We have developed a computationally efficient trajectory generator for six degrees-of-freedom multirotor vehicles, i.e. vehicles that can independently control their position and attitude. The trajectory generator is capable of generating approximately 500’000 trajectories per second that guide the multirotor vehicle from any initial state, i.e. position, velocity and attitude, to any desired final state in a given time. In this video, we show an example application that requires the evaluation of a large number of trajectories in real time.

Multirotor vehicle

The multirotor vehicle used in the demonstration is an omni-directional eight-rotor vehicle. Its unique actuator configuration gives it full force and torque authority in all three dimensions, allowing it to fly novel maneuvers. For more details, please refer to the Youtube video or the research paper: “Design, Modeling and Control of an Omni-Directional Aerial Vehicle”, IEEE International Conference on Robotics and Automation (ICRA), 2016.

Researchers

Dario Brescianini and Raffaello D’Andrea
Institute for Dynamic Systems and Control (IDSC), ETH Zurich, Switzerland – http://www.idsc.ethz.ch

Location

Flying Machine Arena, ETH Zurich, Switzerland.

Acknowledgements

This work is supported by and builds upon prior contributions by numerous collaborators in the Flying Machine Arena project. See the list here. This research was supported by the Swiss National Science Foundation (SNSF).

Jamie Paik with a robot. Credit: NCCR Robotics

Meet the NCCR Robotics Paik Lab (RRL, EPFL) – headed by Professor Jamie Paik, the lab is dedicated to creating interactive robotic systems using cutting edge manufacturing techniques. The lab specialises in creating soft, foldable robots for use in a variety of situations, including creating compliant robotic assistive devices for people with disabilities.

If you enjoyed this ‘meet the lab’ video, you can also watch another in the NCCR Robotics series below:

Over recent years the explosion in popularity of drones, both professionally and for amateur use, has inspired researchers to consider how to make flying robots as safe and robust as possible. Previous design methods have included producing bulky protective cages or making them as unlikely to crash as possible. Recently, researchers from Floreano Lab, NCCR Robotics and EPFL have presented a new approach to making crash resilient quadcopters – making them soft, so it doesn’t matter if they come into contact with their surrounding environment.

Improving on a previous iteration of a folding quadcopter, Stefano Mintchev, the lead researcher on the project, developed a quadcopter utilising the dual stiffness properties seen in insect wings. Insect wings are composed of sections made of cuticle, a stiff material that takes the load bearing portion of the wing, connected with flexible joints made of the protein resilin that have evolved to be shock absorbent and compliant. These two factors together allow insect wings to be both strong and load-bearing, and compliant and durable.

The presented drone is made of a central case and a thin fibreglass external frame with four arms held together by four magnetic joints. As this fibreglass frame is only 0.3mm thick, it is soft and flexible, making it able to withstand collisions without permanent deformation. The four magnetic joints connect the frame to the central case (modelled after hard insect exoskeletons, just to complete the inspiration from nature) and rigidly hold the frame in place during flight. Where these magnets come into their own, is that during a collision they break, meaning that the drone transition to a soft state where the frame becomes disengaged and can safely deform without damaging itself or the inner core. Soft elastic bands ensure that the frame is held close enough in place that the magnets snap back after the collision, allowing the frame to realign and thus ensuring that the drone is once again ready to fly.

The collision resistant drone was tested by dropping it from a height of 2m whereby it completely disengaged the magnetic joints and automatically restored to its pre-crash configuration. In fact, the drone was dropped over 50 times with no permanent damage. On top of that, the design means that the drones can have as many rotators as desired and is not limited to a quadcopter configuration.

Reference

S. Mintchev, S.D. De Rivas and D. Floreano. Insect-Inspired Mechanical Resilience for Multicopters, In IEEE Robotics and Automation Letters, 2017.

Kickstart Accelerator, one of Europe’s largest multi-corporate, zero-equity technology accelerators and an initiative of digitalswitzerland, has today announced that applications are open to international startups for its second programme.

Kickstart Accelerator will select a shortlist of up to 30 startups who will participate in an 11-week programme designed to help them develop their ideas and products across one of the programme’s verticals, including robotics & intelligent systems. In order to tap into unexplored innovation potential, Kickstart Accelerator has entered into a partnership with BaseLaunch (initiated and operated by BaselArea.swiss) to offer a healthcare-specific vertical in the life sciences hotspot Basel.

Image: Philippe Rossier

Successful applicants will be international startups with promising business ideas that have the potential to disrupt the chosen verticals and benefit the wider society. The accelerator will be operated by Impact Hub Zurich, which is part of the largest international network of entrepreneurship and innovation centers, giving the startups access to the brightest talent across the globe.

Patricia Schlenter, Programme Manager at Kickstart Accelerator, said,

Our inaugural year saw over 850 applications from across the globe and so we are looking forward to seeing the calibre of this year’s innovators. The Swiss ecosystem offers startups the opportunity to work with like-minded entrepreneurs, experienced mentors and some of the biggest corporate players to deliver impactful innovations to key industries.

This year’s shortlisted startups will meet with over 15 corporate partners and mentors, including Switzerland’s largest ICT provider Swisscom, multinational insurance firms Swiss Life and AXA Winterthur, Swiss financial services companies Credit Suisse, UBS and Raiffeisen, global consultancy firms EY and PwC, as well as Switzerland`s largest food retailers Migros and Coop among others.

Image: Philippe Rossier

The 2016 cohort led to six partnerships between the startups and corporates. Applicants for 2017 will also have the opportunity to secure a ‘Proof of Concept’ trial with one of the corporate partners. These trials will allow the startups to test the application and scalability of their products in a demanding corporate environment. The trials will also provide the startups with the best possible chance of exploring longer-term commercial partnerships with leading corporate titans and the opportunity to further develop their market offering.

Carola Wahl, Head of Transformation & Market Management at AXA Winterthur, says,

Innovation is a key area of focus for our business and we are committed to working closely with other companies to promote and strengthen Switzerland’s status as an innovation and digital hub. We are particularly interested in ‘smart cities’ as they will strongly influence society’s mobility and have a major impact on the insurance industry. Cooperation between the startups and corporate partners will allow the entrepreneurs to benefit from the corporates’ know-how and large customer networks, as well as enable them to develop new technologies and disruptive products together.

The programme will begin on 4 September, with the official Opening Ceremony taking place on 7 September in the accelerator space at the ewz-Unterwerk Selnau. The Final Demo Day and closing event will be held on 17 November, where each team will present their products to investors, corporate leaders and the media. The ewz-Unterwerk Selnau, an 8,611 sq ft. (800 sq m) industrial building, will house co-working areas, meeting rooms, brainstorming areas, pitching stages and relaxation zones designed from old shipping containers to create a collaborative environment for creativity and success.

Image: Philippe Rossier

Kickstart will not be taking any equity from the participating startups. Founders will have the chance to win up to 25`000 CHF, as well as receiving a monthly founder stipend and masterclass sessions with mentors from the corporate partners and the Swiss innovation ecosystem. Kickstart aims to develop close collaboration between the corporate partners and the startups, as well as between the startups themselves across the different verticals, during and beyond the duration of the programme.

Nicolas Bürer, Managing Director of digitalswitzerland, commented, “With the second edition taking place in Zurich and the extension of the programme to Basel, Kickstart will be one step closer to becoming the largest European startup Accelerator. digitalswitzerland is also looking to extend the scope of the programme and is carrying out research ahead of establishing Kickstart Accelerator and additional verticals in Lausanne. This is another step towards establishing Switzerland as a leading digital innovation hub worldwide.”

To apply for the programme, please visit: www.kickstart-accelerator.com.

Léa Pereyre creating new drone costumes. Credit: Verity Studios

Drone costume designer Léa Pereyre showcases several of her imaginative designs and describes her experience with dreaming up new concepts for this emerging art form.

Check out more designs on their Drone Costume Design Instagram, find it here.

The video below shows clips from the Broadway show PARAMOUR, created by Cirque du Soleil. The flying lampshades soaring over the actors are real. In fact, it’s a special type of magic we do here at Verity Studios. We develop drone shows for entertainment industries.

Once we knew lampshades can fly, we asked ourselves: so what else can fly? This is how I became a drone costume designer. When I arrived, I was given a blank slate. Except for the lampshades, little work existed in this type of field. I needed to conduct research, tests, and experiments, and that meant a number of failures. But with each failure, working designs were right around the corner. In 9 months, we developed lots of costumes. I tried to explore all kinds of varying designs, while at the same time learning about drone technology and its limitations and challenges.

Below, you can find a selection of costume designs.

This first costume is based on a resonance effect. The quad, by flying at the right oscillations frequency, excites the costume movement, giving it a distinct personality. Resonance is often encountered in engineering but usually with negative connotations.

When we create a costume, we have several physical constraints. One of them is the weight. For an 80 cm quad like the one we work with, the maximum costume weight is 250gr. This one (above) is built with a very lightweight and flexible polystyrene foam fixed on a carbon structure.

Each costume is related or will be related to a choreography. So we can decide to design a costume for a specific movement we would like to play with.

Reverse effect on the costume using the drone movement.

This costume is very lightweight: only 150 gr. The white parts are made to catch air. That way, when the quad is flying with large up and down movements the costume reverses. They are all connected with thin carbon rods braided together, providing a nice pattern.

In the next experiment, we aimed to create playful light interaction. We thought it would be interesting, as an alternative, to make use of reflected light.

The result is a simple costume built with mirror surfaces.

And then when you project light onto it, it creates reflections on the wall and ceiling.

And also on the costume itself: it becomes the screen of random graphic effects, giving it an eerie look.

The downward draft created by the drone poses major design challenges for all of the costumes. Since it’s impossible to ignore, why not use it to actuate something on the costume itself? That way we can use it to our advantage. Looking at the GIF below, the blue surface under the quad catches air — as it’s related by wires to the costume — so it creates a “pop-up” movement.

Every time the quad takes off the costume will change shape:

This costume was explored the concept “opening flowers”.

We imagined it at the Singapore airport, in baggage claim. There are giant flowers flying over people, landing on specific platforms to recharge, allowing people to observe the flowers/costumes. Each time the quads take off the costumes would blossom, like flowers.

We are only scratching the surface for this art form, there is still so much terrain to explore. We look forward to continuing this research and I hope for the moment you are inspired to imagine the infinite possibilities within this area.

All images credit Verity Studios.

Check out more designs on their Drone Costume Design Instagram, find it here.

If you enjoyed this article, you may also want to read:

• Drone shows: Creative potential and best practices
• New quadrocopter video points to a future for flying machines in entertainment
• Raffaello D’Andrea at TED2016: Novel flying machines and swarms of tiny flying robots
• SPARKED wins at New York City Drone Film Festival
• Flying robots perform 100th show on Broadway, using new localization technology and algorithms
• Behind the scenes at TED Global: Raffaello D’Andrea and team demo amazing quadrotor “athletes”

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

On 8 October 2016, the world’s first Cybathlon took place in Zurich, Switzerland. The event, organised by ETH Zurich with NCCR Robotics as presenting sponsor, offered the opportunity for people with disabilities to work with technology providers to create solutions that would help them to complete a series of tasks of daily life.

Teams were invited to compete in one of six disciplines, BCI Race, FES Bike Race, Powered Arm Prosthesis Race, Powered Leg Prosthesis Race, Powered Exoskeleton Race and Powered Wheelchair Race and 400 contestants took part in one of the races.

If you weren’t able to attend the Cybathlon in person, or want a look back, this video from the organisers is the next best thing.

T=0h. Autonomous (hand-) launch.

One year after having demonstrated the 81-hour continuous solar-powered flight that is still the current world record in flight endurance for all aircrafts < 50kg total mass, the AtlantikSolar UAV has completed its next milestone by demonstrating the first-ever fully autonomous (from launch to landing) solar-powered perpetual flight with significant payload (Color + Thermal Camera) in a 26-hour Search-and-Rescue (SaR) mission.

While the 81-hour and 28-hour endurance record flights were important milestones that demonstrated the perpetual endurance capability of AtlantikSolar, they required manual pilot control for launch and landing and did not carry any aerial imaging payload. However, the missions that our team really cares about – Search-and-Rescue missions relying on long-endurance aerial sensing to support authorities e.g. in the European refugee crisis currently unfolding over the Mediterranean Sea – require both of these elements, i.e. ease-of-use through full launch-to-land aircraft autonomy as well as significant payloads to help the rescue teams with the detection of victims on land and sea.

The 26-hour solar-powered Search-and-Rescue flight performed by AtlantikSolar AS-3 from July 19^th – 20^th 2016 demonstrated exactly that, and is, therefore the first-ever flight worldwide to combine:

• Perpetual flight: 26-hours of solar-powered day/night- and thus energetically-perpetual flight.
• Full aircraft autonomy: No pilot stick moved within 26-hours of flight.
• SaR payload: The aircraft carried a 10 Watt 300g payload (1 Color camera, 1 Thermal Camera, 1 ODROID onboard computer with WLAN) and performed victim detection from the air during day and night.
• Environment-aware: The aircraft performed automatic thermal updraft tracking for increased energetic efficiency and to speed up the battery recharge.

Flight summary

The 26-hour flight started on July 19^th at 18:02 local time in Hinwil, CH with full batteries. The launch was performed fully autonomously: After all system checks were complete, the aircraft was tossed in the air via a hand-launch and then continued automatically and without pilot interaction towards its first loitering waypoint.

T=2h. Circling above while live-streaming camera data.

The respective flight control technology is based on an ETHZ/3DR Pixhawk autopilot with a custom flight controller designed at the Autonomous Systems Lab. Equipped with a color camera, thermal camera, an onboard computer and wireless LAN, the aircraft began live-streaming the respective images. The full payload was operated until around 21 o’clock, after which the color camera was switched off because of the insufficient lighting conditions. The batteries were at 95% state of charge at that time, having started their discharge shortly before 20 o’clock. Note that operating a fully-fledged SaR payload consuming 10W is a significant challenge for perpetual flight on a small-scale solar-powered UAV such as AtlantikSolar, and the overall power consumption of ~60W was thus closely tracked during the first hours of the evening flight.

T=5h. Flying at night with position indicator LEDs on.

T=5h. The airplane is seen loitering in the top left, performing the SolAIR Search-and-Rescue mission.

The actual testing of the Search-and-Rescue capabilities started just before 23:00. With the aircraft now flying in total darkness, the infrared camera served as the only source of aerial imaging information. As visible in the video, the payload system clearly manages to find the victim lying in low grass (and surrounding houses, tents, cars, the streets and especially the warm electric generator) at 23:05. The victim detection was performed manually by the ground station operator based on the live-streamed images this time. However, the next AtlantikSolar test flight will have automatic on-board victim detection (as already tested in the ICARUS search and rescue project) implemented. These demonstrated capabilities are integral elements for perpetual flight and aerial victim detection missions. We are convinced they can be of great help in solving pressing issues, such as the European refugee crisis of 2015 and 2016 above the Mediterranean Sea.

T=5h. Live-streamed thermal camera images with annotation. Note the victim that can easily be detected.

T=13h. Ground Station on the next morning. We’ve received first sun here.

Despite heavy winds of up to 8m/s, the Search-and-Rescue support activities with the infrared camera payload were continued throughout the rest of the night. The sun hit at 06:20 local time on July 20^th and the minimum battery state of charge was reached with 26% battery energy remaining at 08:04. Considering the additional payload power consumption (and mass) of 10W , this energetic margin – achieved on July 20th, and thus about one month after the solar solstice on June 21st – is a success and even exceeds the margin of 23% predicted by our simulations. To accelerate the battery recharging process, the aircraft also implemented autonomous thermal updraft tracking that was enabled during the late morning once thermal updrafts were encountered (see video). Multiple “free” altitude gains of >100m were achieved this way – again without any pilot interaction. The batteries were fully re-charged at 15:30.

T=26h: Final approach during the autonomous landing.

As a final step, and after 26-hours of solar powered flight, the aircraft performed a fully autonomous landing at the Hinwil, CH airfield. Using its lightweight LIDAR (Light Detection And Ranging) sensor to measure its distance to the ground, AtlantikSolar – a hard to fly aircraft that can usually only be steered and landed by extremely experienced pilots – could safely perform the automatic landing. We consider the demonstrated full flight autonomy a vital step to allow search-and-rescue support teams, which usually do not possess extensive UAV flight training, to benefit from the significant advantages of solar-powered and in general high-performance UAVs.

T=26h. Landed autonomously.

AtlantikSolar AS-3 after its 26-hour fully autonomous solar-powered SaR mission.

The small operating post in Hinwil, CH.

Live-streamed RGB camera image. Our tents are clearly visible.

Further information

Detailed design and technical information on the UAV platform can be found in “Oettershagen P, Melzer A, Mantel T, Rudin K, Lotz R, Siebenmann D, Leutenegger S, Alexis K, Siegwart R (2015), A Solar-Powered Hand-Launchable UAV for Low-Altitude Multi-Day Continuous Flight. In: IEEE International Conference on Robotics and Automation (ICRA)” [Download] .

An additional up-to-date publication, including the research for this flight, is planned.

Some more impressions from the flight were broadcasted live through our twitter account.

Acknowledgements

This research was funded through the research project SolAIR – Solar-powered Automated Aerial Imaging and Reconnaissance Using Infrared Cameras. SolAIR is a project funded under Armasuisse contract #043-12. The AtlantikSolar project is in addition funded with ETH Zurich’s internal resources, private supporters, and the European Union FP7 Search-And-Rescue research projects ICARUS and SHERPA .

Multiple project partners and collaborators have contributed towards making this important milestone possible, and we’d like to thank all of them for their various and ongoing support. Finally, we are grateful towards the Hinwil and Rafz model aeroplane clubs for providing the airfield!

Pilots: Rainer Lotz, Adrian Eggenberger. Development and Operations Team (Autonomous Systems Lab): Philipp Oettershagen, Rainer Lotz, Amir Melzer, Thomas Mantel, Bartosz Wawrzacz, Konrad Rudin, Thomas Stastny, Timo Hinzmann, Dieter Siebenmann, Dr. Gregory Hitz, Prof. Dr. Roland Siegwart.

The AtlantikSolar project was developed at the Autonomous Systems Lab at ETH Zurich. 

If you liked this article, you may want to read:

• Solar-powered flight for 81 hours: A new endurance world record
• Solar powered day/night autonomous flight achieved: Airborne for 28 hours without fuel!
• Flying Ring robot can fly on its side
• IDSC Tailsitter’ flying robot performs vertical loops and easily transitions between hover and forward flight
• ‘Tailsitter’ flying robot hovers and recovers easily thanks to new algorithm

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

The Flying Ring in action. Source: Rajan Gill/YouTube

The Flying Ring is a new flying vehicle being developed at the Institute for Dynamic Systems and Control, ETH Zurich. The goal of the project is to fully characterize all aerodynamic properties of the vehicle. While traditional quadcopters are agile and carry high payloads they are not efficient in forward flight, with traditional lift to drag ratios comparable to a fruit fly. The Flying Ring vehicle, however, can fly on its side, allowing the blades to propel it forward faster than a typical quadcopter.

The video depicts the first prototype flying tethered. The annular wing (or ring) has a flat airfoil shape, which also covers the propellers and enhances human safety. These autonomous controlled flights help extract aerodynamic properties of the vehicle. A lift to drag ratio (which is a metric for aerodynamic efficiency) of 12 is achieved for the ring only. The total vehicle lift to drag ratio is lower, but can be substantially improved upon with an optimized design. Further details will be submitted to a future conference or research journal.

Why is the Flying Ring tethered? Flying tethered is an important part of the test, as it is used to characterize the steady state operating conditions at various flight speeds in a tight space, namely:

• Thrust of the propeller in forward flight
• Analysing annular wing lift and drag
• Evaluating body drag

In terms of structure, the vehicle is a standard quadrotor configuration. It has depron foam sheet attached via zip ties to the four motor mount arms, with black carbon slab wrapped around the foam.

Solidworks render of the vehicle, Flying Ring. Photo credit: Rajan Gill

Links to other videos shown:
Quadrotor pole acrobatics
Cooperative quadrotor ball throwing and catching
Onboard quadrocopter failsafe: flight after actuator failure
Flying Robots, Builders of tomorrow

Researchers
Rajan Gill and Raffaello D’Andrea
Institute for Dynamic Systems and Control (IDSC), ETH Zurich, Switzerland
ETH Zurich, Flying Machine Arena

Acknowledgments
This work is supported by and builds upon prior contributions by numerous collaborators in the Flying Machine Arena project.

This research was funded in part by the National Research Council of Canada (NSERC) and the Swiss National Science Foundation (SNSF).

If you enjoyed this article, you may also want to read:

• ‘IDSC Tailsitter’ flying robot performs vertical loops and easily transitions between hover and forward flight
• ‘Tailsitter’ flying robot hovers and recovers easily thanks to new algorithm
• Multiple tethered quadrotors whip around a pole together at high speeds 
• Quadrocopter failsafe algorithm: Recovery after propeller loss
• Three new quadrotor videos demonstrate agile control and the power of machine learning
• Video: Quadrocopter learns from its mistakes, perfects slalom air racing

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Photo: Cirque du Soleil – PARAMOUR on Broadway – at the Lyric Theatre. Featuring Flying Machine Design and Choreography by Verity Studios. Pictured: Ruby Lewis as ‘Indigo’ Ryan Vona as ‘Joey’. ©, Cirque du Soleil Theatrical. Photo by: Richard Termine

Since April, a troupe of eight flying machines has been performing in a Cirque du Soleil Broadway show called Paramour. This group of quadcopters has now completed its first 100 shows in front of a live theater audience, without a single incident. Given the string of recent safety incidents with drones (there’s more), this begs the question: How was this accomplished?

The Paramour quadcopters were designed and created by Verity Studios of Zurich and were transformed into flying lampshades in collaboration with Cirque du Soleil. Some readers may recognize them as the direct siblings of the similarly dressed quadcopters in Sparked: A Live Interaction Between Humans and Quadcopters; a short movie shot over the span of two days in the controlled environment of a research lab (see previous Robohub article and Quadrotors vs. CGI Q&A.) What sets the Paramour quadcopters apart, and the key to their ongoing success on Broadway, are a new localization technology and fail-safe algorithms, that keep the fully redundant quadcopters safely on course, performing 8 times a week, in front of a live audience of up to 2,000 people, without nets.

The people behind Verity Studios are no strangers to performing quadcopters. Founder Raffaello D’Andrea is a professor of control systems at the Swiss Federal Institute of Technology (ETH Zurich), from which Verity Studios was spun off. From a lab aptly named the Flying Machine Arena he has been conducting research for over 10 years on complex, autonomous flight, using a high-precision motion capture system to guide the vehicles. The ETH team’s first dancing drones performed in 2009 as part of research by Prof. D’Andrea’s former PhD students, Federico Augugliaro and Angela Schoellig. The group first stepped into the public performance space in 2011 with Flight Assembled Architecture, the world’s first multi-quadcopter performance in front of a large audience. In all, more than 200 live research demonstrations have taken place so far in the Zurich lab with occasional appearances given abroad, such as Google IO 2012.

While the team used motion capture technology extensively over this period, this type of localization technology proved inadequate for a long-running Broadway production when taken out of the research laboratory. The fundamental issue is that motion capture systems rely on a centralized architecture whereby all commands are forwarded to a single computer. A failure in that computer’s hardware or software may cause a sudden loss of control for the complete fleet.

Whereas an occasional failure of this type may be inconsequential in a research environment like the Flying Machine Arena, it is unacceptable for most commercial and industrial applications. The live events industry, in particular, has high safety standards owing in part to the amplification of safety risks when performing close to crowds of people. In addition to the safety risks, the consequences of a mishap entailing personal injury can be severe in terms of negative publicity, brand damage, and litigation.

Nevertheless, motion capture based performances near a live audience have been attempted, such as in this recent America’s Got Talent performance.

https://www.youtube.com/watch?v=1CjX1r-gh8U

To address these shortcomings, Verity Studios moved away from vision-based localization and developed a new system specifically for industrial applications that must meet strict safety and reliability standards. As stated by Raffaello D’Andrea at a recent TED talk, both the new radio-frequency based proprietary localization system and the flying machines are redundant and use fail-safe algorithms such that every vehicle can withstand any single point of failure.

Another key factor in the system’s success is its interoperability within a theatrical environment. Any theatrical system must function within a complex ecosystem of stage automation where stringent industry standards prevail.

“These flying machines have met or exceeded all expectations in terms of safety, reliability, maintenance, and ease of operation,” states Michael Shepp, Automation Carpenter for Paramour.

The technological achievement of creating a safe and robust system for flying a multitude of vehicles before a live audience introduces a rich palette for artistic expression. Creative staff at Cirque du Soleil recognized this potential and have worked side-by-side with Verity Studios to achieve this milestone on Broadway. Cirque du Soleil Chief Creative Officer, Jean-Francois Bouchard, states: “The flying machines are unquestionably one of the most important statements of the Paramour show.”

Cirque du Soleil and Verity Studios are currently exploring the artistic use of flying machines in other upcoming productions.

PARAMOUR runs at the Lyric Theatre (213 West 42nd Street) in New York.

If you enjoyed this article, you may also want to read:

• Raffaello D’Andrea at TED2016: Novel flying machines and swarms of tiny flying robots
• New quadrocopter video points to a future for flying machines in entertainment
• Quadrotors vs CGI: A Q&A with the makers of Sparked
• Behind the scenes at TED Global: Raffaello D’Andrea and team demo amazing quadrotor “athletes”
• Video: Throwing and catching an inverted pendulum – with quadrocopters
• Surrounded by his quadrocopter drones on stage, Raffaello D’Andrea explains feedback control and talks about the coming Machine Revolution

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

The IDSC Tailsitter has been designed at the Institute for Dynamic Systems and Control, ETH Zurich, as a testbed for novel control algorithms for tailsitter vehicles. The goal of the project is to develop controllers that enable agile and robust flight for all flight regimes, such that the full potential of these vehicles can be exploited.

Airframe based on a Clark Y profile. Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

The airframe of the vehicle is based on a Clark Y profile and designed such that for regular flight the pitching moment vanishes for zero flap angle, and such that the aerodynamic neutral point coincides with the vehicle’s center of gravity. The objective of this design is to allow agile maneuvers for all flight regimes and to avoid flap angle saturation problems caused by large trim angles.

Internal structure. Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

The internal structure of the vehicle is built upon a core of a carbon sandwich composite material. The motors and servos are attached to the core using 3D-printed mountings, where the servos are placed such that they can be directly connected to the flaps. Further, a set of wing profile ribs and two carbon fiber tubes on the side for protection are mounted to the core structure. The electronics are placed at the center of the vehicle, and the battery at the front such that the center of gravity is at the desired position. All parts of the vehicle are screwed together (no glue is used), in order to simplify the replacement of broken components. The tailsitter’s wingspan is 48cm and the total weight is 150g.

The vehicle is controlled by a global controller enabling recovery to hover from any initial condition. A cascaded control architecture is used: Based on position and velocity errors an outer control loop computes a desired attitude keeping the vehicle in coordinated flight, while an inner control loop tracks the desired attitude using a lookup table with precomputed optimal attitude trajectories. The controller runs with an update rate of 500Hz on a Cortex M4F microprocessor. The vehicle is able to communicate with a ground station using an nRF51822 chip from the company Nordic Semiconductor. Communication can be established for recording telemetry data or for sending high-level commands to the vehicle, such as “take-off” or “land”. However, the vehicle is able to fly autonomously, the trajectories that are being tracked are stored on-board.

The on-board state estimation algorithms and technology are provided by the ETH spin-off company Verity Studios.

The attitude control algorithm is presented in the research paper “A Global Strategy for Tailsitter Hover Control”, International Symposium on Robotics Research (ISRR), 2015.

Researchers

Robin Ritz and Raffaello D’Andrea
Institute for Dynamic Systems and Control (IDSC), ETH Zurich, Switzerland
Flying Machine Arena

Technical details

Airframe: Custom design based on a Clark Y profile
Electronics: Custom design using a Cortex M4F microprocessor
Battery: Thunder Power RC G8 Pro Lite 25C LiPo 480mAh 2S
Motors: Hacker A05-13S
Motor controllers: Dys SN20A Mini ESCs with SimonK firmware
Propellers: 5×3 GWS EP-5030
Flap servos: MKS DS65K
Infrastructure: Flying Machine Arena

If you enjoyed this article, you may also want to read:

• ‘Tailsitter’ flying robot hovers and recovers easily thanks to new algorithm
• Multiple tethered quadrotors whip around a pole together at high speeds 
• Quadrocopter failsafe algorithm: Recovery after propeller loss
• Three new quadrotor videos demonstrate agile control and the power of machine learning
• Video: Quadrocopter learns from its mistakes, perfects slalom air racing

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Autonomous exploration of unknown environments corresponds to a critical ability and a major challenge for aerial robots. In many cases, we would like to rely on the ability of an intelligent flying system to completely and efficiently explore the previously unknown world and derive a consistent map of it. On top of this basic skill, one can then work on several tasks such as infrastructure inspection, hazard detection, and more.

Source: Dr Kostas Alexis, UNR

Our algorithm “Receding Horizon Next-Best-View Path Planning” is a recent contribution towards enabling the key goal of autonomous exploration. It achieves this by sampling finite-depth candidate paths within the environment, selecting the one that maximizes the amount of new space to be explored, and executes only the first step while then repeating the whole process in a receding horizon fashion. By performing multiple iterative steps of this process the space is fully and efficiently explored, and a volumetric representation is derived. Finally, one can afterwards launch a second mission for higher-fidelity surface inspection and more accurate 3D reconstruction of the environment.

The algorithm has been experimentally verified with aerial robotic platforms equipped with a stereo visual-inertial system, as shown in our video:

Finally, to enable further developments, research collaboration and consistent comparison, we have released an open source version of our exploration planner, experimental datasets and interfaces to established simulation tools, including demo scenarios. To get the code, please visit: https://github.com/ethz-asl/nbvplanner/

This research was conducted at the Autonomous Systems Lab, ETH Zurich and the University of Nevada, Reno.

Reference:

1. Bircher, M. Kamel, K. Alexis, H. Oleynikova, R. Siegwart, “Receding Horizon “Next-Best-View” Planner for 3D Exploration”, IEEE International Conference on Robotics and Automation 2016 (ICRA 2016), Stockholm, Sweden. Open-Source Git Repo: https://github.com/ethz-asl/nbvplanner

UAV developed by Ascending Technologies. Photo credits: TRADR

The University of Oulu will host a summer school on heterogeneity in Robotic Systems this August in Oulu, Finland, where the latest advances and developments in the field of European research within this area will be presented.

The euRathlon/TRADR summer school 2016 will take place from 22-26 August and will provide participants with both theoretical and practical insight in multi-domain (ground, marine and aerial) real robotic systems for deployment in disaster response scenarios.  The trend in this area is towards multi-robot systems with different platforms, processing powers and operational spaces (ground, water, air) that will be deployed over long periods and several sorties. This raises many challenges including multi-modal heterogeneous mapping, semantic analysis and reasoning, collaborative planning under uncertainty, and the integration of mapping and planning.

The summer school programme has been designed to provide attendees with hands-on experience; they will work on practical tasks using several robots with different sensory equipment.

Three invited speakers will give master classes. The keynote speakers confirmed are:

• Jan Peters  from the Technische Universitaet Darmstadt and Max-Planck Institute for Intelligent Systems (Germany),
• Cesar Dario Cadena Lerma from ETH Zurich (Switzerland), and
• Matthijs Spann from TU Delf (The Netherlands).

The intended audience of the summer school is undergraduate students, Master students, PhD students, postdoc students, researchers from universities/organisations and engineers from industry companies around the world. The summer school will provide an opportunity for attendees to deepen their understanding of heterogeneous robotics systems and share ideas and experiences. Participants can optionally present a paper/poster during the summer school.

Participants of euRathlon/SHERPA 2015 summer school during the hands-on experience with domain-specific simulators. Photo credits: euRathlon

During their stay in Oulu, participants will extend their knowledge by learning about the latest advances in multi-domain real robotic systems for deployment in disaster response scenarios.

In addition to improving their knowledge in field robotics, the event constitutes a great opportunity to meet professionals and specialists with common interests and can serve to create new teams willing to participate in the ERL Emergency competition in 2017.

The call for participation in the summer school is now open and full information is available on http://www.eurathlon.eu/index.php/workshop/summerschool2016/

The summer school is jointly organised by EURATHLON and TRADR research projects funded by the Seventh Framework Programme and the Horizon 2020 Programme of the European Commission, respectively.

Participants of euRathlon/SHERPA 2015 summer school test the USV on the lake in Oulu. Photo credits: euRathlon

euRathlon is an outdoor multi-domain robotic competition inspired by the 2011 Fukushima accident. The euRathlon Challenges requires teams of land, underwater and flying robots to work together to survey the scene, collect environmental data, and identify critical hazards. After three successful years, euRathlon takes a step further under the RockEU2 EU-Horizon 2020 project.  RockEU2 builds on the success of the RockEU FP7 coordination action, together with the expertise in robotics competitions generated within euRathlon, RoCKIn and EuRoC EU-FP7 projects. The approach to robot competitions will be transitional and experimental. RockEU2 traces the first steps of a novel model for competitions: the European Robotics League (ERL). The ERL model will be tested for viability alongside its implementation during the next two years, in which euRathlon will become ERL Emergency Robots.

Watch the video resume of the euRathlon 2015 Grand Challenge:

TRADR is a research project. It focuses on long-term human-robot teaming for robot-assisted disaster response and addresses the scientific challenges arising from making the experience of a human-robot disaster response team persistent over multiple sorties during a prolonged mission. Using a proven-in-practice user-centric design methodology, TRADR develops novel science and technology for human-robot emergency teams.

Ground robots used in survey and rescue missions by TRADR. Photo credit: TRADR.

Different types of robots collaborate with human team members to explore the environment, and gather physical samples. Throughout this collaborative effort, TRADR enables the team to gradually develop its understanding of the disaster area over multiple synchronous and asynchronous sorties (persistent environment models), to improve team members’ understanding of how to work in the area (persistent multi-robot action models), and to improve team-work (persistent human-robot teaming).

Watch the video of TRADR Joint exercise in Dortmund, Germany:

Fig. 1. The Monospinner in flight.

The Monospinner (Fig.1), developed at the Institute for Dynamic Systems and Control at ETH Zurich, is the mechanically simplest, controllable, flying machine in existence. It has only one moving part (the rotating propeller), but can still fully control its position in space. The vehicle features no additional actuators or aerodynamic surfaces. 

Our research group aims at pushing the boundaries of flying machines by asking fundamental questions, such as “what is the minimum number of moving parts necessary for controlled flight?” All common flying vehicles require multiple moving parts: conventional quadrocopters, for example, have four moving parts (the four fixed-pitch propellers).  A helicopter’s main rotor requires a complicated swashplate mechanism with many moving parts, and a typical fixed-wing airplane requires one moving part for each of the ailerons, rudder, elevator, and main propulsion. Samara-type vehicles look like maple seeds (or samaras), and rotate while flying. These vehicles typically need two actuators to be controllable in position. Some toys have only one moving part, but are not controllable in the horizontal direction.

We set out to create a vehicle that has only a single moving part. The theoretical basis for this followed from previous work on quadrocopters, where we showed that a quadrocopter can maintain flight despite the complete loss of one, two, or three propellers. To do this, we redefined the definition of “to hover”: now the vehicle may rotate at a constant angular velocity as long as it remains approximately at the same point in space. Of course, the vehicle then has to be controlled near this hover solution, to allow it to track trajectories and reject disturbances.

This is tricky for the Monospinner, as it has only a single input (the thrust force) to control its states (compared to a conventional quadrocopter that has four inputs). We designed a cascaded controller (Fig. 2): the faster inner loop controls the thrust direction, while the slower outer loop controls the vehicle’s acceleration and thereby position. Roughly speaking, the single control input (the thrust magnitude) is decomposed into two parts, the average part of the thrust (calculated by the outer loop) which determines the acceleration of the Monospinner and the deviation from the average thrust (calculated from the inner loop) which controls its orientation.

Fig. 2. Cascaded control structure: the outer position controller defines a desired acceleration, where the inner attitude controller defines the vehicle’s attitude.

After the theoretical analysis, we proceeded to build a vehicle. However, there are a lot of uncertainties in the real world: one example is that we do not have a good aerodynamic model of such a complex rotating object. In addition, there are uncertainties such as the mass distribution or the position of the vehicle’s center of mass. We set out to design something that would fly even if we did not know the parameters exactly. We evaluated different designs using Monte Carlo simulations, where we sample different perturbations from the above-mentioned uncertainties and use simulations to test whether our controller would still work. We did this until we found a configuration that works in most situations: the resulting Y-shaped vehicle is shown in Fig. 3 below.

Fig. 3. Monte Carlo simulation results, showing how likely a vehicle is to be controllable (the color scale indicates the likelihood of a crash) as a function of where the vehicle’s electronics are placed. The vehicle’s approximate size and shape are based on existing vehicles.* The vehicle has three main components, which are approximately equally massive: the battery, electronics, and the motor/propeller. By fixing the positions of the propeller and the battery as two vertices of an equilateral triangle, a Monte Carlo analysis was conducted for different positions of the electronics in the vicinity of the third triangle vertex. The final electronics position was chosen as a compromise between low likelihood of failure (as determined by the Monte Carlo simulations) and other considerations (such as ease of mechanical construction). This location is plotted with a red dashed line.

*Link to research

The control strategy only works near hover, where the vehicle spins about 4 revolutions per second. To get the vehicle near the operating angular velocity, we built a passive platform (Fig. 4 below), which has a vertically oriented bearing allowing the Monospinner to rotate freely. The rotation is achieved through the reaction torque of the propeller, and the thrust is slowly ramped up from zero. Once the vehicle is sufficiently near the hover angular velocity, the controller is switched on and the vehicle jumps off the platform. The platform ensures that the take-off condition is near the hover solution for each experiment.  Once we were confident that the vehicle would reliably work from such a controlled starting point, we pushed our luck, and we found out that the system is robust enough to recover after it is thrown into the air like a Frisbee (see the video).

There are still open questions, which we will explore in future work: for example, we plan to refine the control strategy to allow the Monospinnner to recover from a larger range of initial conditions.

Fig. 4. The Monospinner resting on the takeoff platform, which allows the vehicle to freely rotate about its axis of rotation, so that the vehicle can take off near its hover angular velocity and orientation. We have since shown that the Monospinner can also be hand-launched, by throwing it like a Frisbee.

If you liked this article, you may also be interested in:

• Three new quadrotor videos demonstrate agile control and the power of machine learning
• Raffaello D’Andrea at TED2016: Novel flying machines and swarms of tiny flying robots
• Behind the scenes at TED Global: Raffaello D’Andrea and team demo amazing quadrotor “athletes”
• Quadrocopters learn from prior experience to improve slalom flying

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

The 3-month program runs over the summer from late August to November and provides mentoring, expertise, up to CHF 25K in seed-funding, living stipends, and office space to the selected teams. The program culminates with a Demo Day, where each startup presents their company to Swiss venture capitalists, corporate leaders, and journalists.

We’re looking for outstanding talents with a brilliant idea in the field of Robotics who have the spirit and dedication to become successful entrepreneurs and change the world.

The accelerator aims to put Switzerland on the map by bringing some of the most promising early-stage startups from different fields to Zurich, and doing everything in its power to make them succeed. Applications are welcome from anywhere in the world.

Kickstart is backed by academia, corporates and the local startup ecosystem. Notable mentors in the robotics field include Roland Siegwart director of the Autonomous Systems Lab at ETH Zurich and co-director of the Wyss Translational Center, as well as Simon Dössegger, previously CEO at skybotix.

You can find more information about the Kickstart program here, the deadline for applications is April 30, 2016.

Drone flying over a field.

by Fintan Burke

The last place you might expect to find drones and rovers is checking up on a corn field, but they could soon join tractors and ploughs on a farmer’s list of must-have agricultural tools, thanks to their potential to reduce pesticide use and increase the amount of crops that can be grown.

It’s part of a move towards so-called precision farming, where farmers use equipment to monitor their crops and respond to issues when and where they occur, rather than applying blanket solutions to an entire field.

The Issue
The dangers of excessive pesticide use on the environment can be traced back to the 1962 book ‘Silent Spring’ by Rachel Carson, which has been credited as starting the modern conservation movement.
The EU now applies restrictions to certain pesticides containing neonicotinoids, which have been linked with the collapse of honey bee populations throughout Europe.
In 2014, an EU study highlighted the benefits of precision farming. Using this method can reduce pesticide and fertiliser runoff, which can greatly damage the local environment

Dr José M. Peña of the Institute for Sustainable Agriculture in Cordoba, Spain, ran the EU-funded TOAS project, in which drones were flown over crops to create weed infestation maps for farmers so they could pinpoint which areas to treat.

‘In Europe, 60 % of the pesticides we apply are herbicides to control the weeds,’ said Dr Peña. ‘(With) the technology applied in the crop we can radically reduce the use of these chemicals, and that is a benefit for the environment and the farmer.’

Dr Peña and his team used drones and image analysis technology, which detects slight differences in field colour, to discover vegetation and competitive weeds. However, weeds and budding crops can appear similar in the early season, when crops are at their most vulnerable.

The solution involved examining crop patterns alongside images. ‘We know the crop follows a pattern, and the vegetation that is out of this pattern is classified as weeds,’ said Dr Peña.

‘So in this way we can integrate the spectral information (and) also the position and the shape of the plants in the software to detect those ones that are weeds.’

Farmers can then apply weedkiller to specific areas, monitor the evolution of their crops over time, and create a photorealistic 3D map of their field by taking aerial pictures from multiple views.

Researchers programmed drones to recognise weeds outside normal crop patterns. Image courtesy of TOAS

Maize, olives

After firstly analysing maize fields and olive groves, the team later found the technology worked for other crops such as sunflowers, almonds and grapes.

‘This demonstrates that the technology and the project can go further than the original idea,’ said Dr Peña. ‘As well, we attained a very high accuracy – we can detect more than 95 % of the weeds in the fields. One important thing is that we can detect the parts of the crop field where it’s free of infestation. This place is the part where the farmer does not have to apply the herbicide.’

Spotting the weeds is just one half of the task, though, and researchers elsewhere are developing unmanned ground vehicles, or rovers, that can complete the job by getting rid of the weeds.

“We can radically reduce the use of these chemicals, and that is a benefit for the environment and the farmer.” Dr José M. Peña, Institute for Sustainable Agriculture, Spain.

‘What we are doing is really demonstrating that it can be done fully automatically,’ said Prof. Roland Siegwart of ETH Zurich, Switzerland, who leads an EU-funded robotics project called FLOURISH to develop a prototype of an integrated drone and rover system.

By scanning different crop characteristics, such as height and canopy cover, the drone can communicate the areas that need attention to the unmanned rover on the ground. The rover then removes the weeds, applies pesticide to a specific area, or highlights areas that may need extra fertiliser to the farmer.

Prof. Siegwart says that this could lead to much more efficient use of pesticides.

‘I would estimate it’s probably a very small fraction of a percent of all chemicals which are sprayed on the field which really has an impact,’ he said. ‘If we have more information you can actually, hopefully, get to a much higher efficiency. With probably 100 times less chemistry put on the field you have exactly the same effect.’

Increased research in agricultural technology may also have the added benefit of removing some stigma about drone technology itself as it helps to solve problems such as how to produce enough food for a growing population.

‘Typically we say that around 20-30 % of the whole collection of food on the field is already lost because there are some issues on the field. If you can reduce this it can really help to feed the world’s society.’

Here is the next set of posts from the OSRF blog, along with videos.

ROS android_ndk: What? Why? How?, with Gary Servín (Ekumen)

What’s ROS android_ndk? Why should you care? How does it work? Gary Servín is with Ekumen, an engineering and software consulting company based in Buenos Aires, Argentina that specializes in ROS, web and Android development. With the backing of Qualcomm and OSRF, Ekumen has been trying to make it both possible and easy to run ROS applications on small Android devices like tablets and cellphones using Android’s native language development kit.

As Gary explains, the increasing performance, decreasing cost, and overall ubiquity of Android devices make them ideal brains for robots. The tricky part is getting ROS packages to play nice with Android, which is where ROS android_ndk comes in: it’s a set of scripts that Ekumen is working on to make the process much easier. Unlike rosjava, ROS android_ndk gives you access to 181 packages from the desktop variant of ROS, with the ability to run native ROS nodes directly.

Ekumen is actively working on this project, with plans to incorporate wrappers for rosjava, actionlib implementation, and support for ROS 2. In the meantime, there’s already a set of tutorials on ROS.org that should help you get started.

ROS on Dronecode Systems, with Roman Bapst (ETH Zurich and PX4)

PX4 is a flight control software stack for autonomous aerial robots that describes itself as “rocket science straight from the best labs, powering anything from racing to cargo drones.” One of these labs is at ETH Zurich, where Roman Bapst serves on the faculty. Bapst works on computer vision and actively contributes to the PX4 autopilot platform.

Bapst starts out by describing some of the great things about the PX4 autopilot: it’s open source, open hardware, and supported by the Linux Foundation’s Dronecode Project, which provides a framework under which developers can contribute to an open source standard platform for drones. PX4 runs on 3DRobotics’ Pixhawk hardware, and once you hook up some sensors and servos, it will autonomously pilot nearly anything that flies – from conventional winged aircraft to multicopters to hybrids.

One of PX4’s unique features is its modularity, which is fundamentally very similar in structure to ROS. This means that you can run PX4 modules as ROS nodes, while taking advantage of other ROS packages under PX4 to do things like vision based navigation and control. Additionally, it lets you easily simulate PX4-based drones within Gazebo, which, unlike real life, has a free reset button that you can push after a crash.

The PX4 team is currently getting their software modules running as ROS nodes on Qualcomm’s Snapdragon Flight drone development platform, which would be a very capable and (affordable) way of getting started with a custom autonomous drone.

ROS 2 on “Small” Embedded Systems, with Morgan Quigley (OSRF)

Morgan Quigley is first author of the authoritative 2009 workshop paper on the Robot Operating System. He’s been Chief Architect at OSRF since 2012, and in 2013, MIT Tech Review awarded Quigley a prestigious TR35 award. In addition to software development, Quigley knows a thing or two about hardware: he helped Sandia National Labs design high-efficiency bipeds for DARPA, and he also gave Sandia a hand with the development of their sensor-rich, high-DOF robotic hand.

Quigley’s ROSCon talk is focused on small (but not tiny) microcontrollers: 32-bit MCUs running at a few hundred megahertz or so, with USB and Ethernet connections. While these types of processors can’t power smartphones or run Linux, they are found in many popular embedded systems, such as the Pixhawk PX4 autopilot. Microcontrollers like these would be much easier to integrate if they all operated under a standardized communication protocol, but there are enough inconvenient hoops that have to be jumped through to run ROS on them that it’s usually not worth the hassle.

ROS 2, which doesn’t rely on a master node and has native UDP message passing, promises to work much better than ROS on distributed embedded systems. To make ROS 2 fit on a small microcontroller, Quigley demonstrates a few applications of FreeRTPS, a portable, embedded-friendly implementation of the network protocol underlying ROS 2.

After showing the impressive results of some torture tests on a Discovery board, Quigley talks about what’s coming next, including a focus on even smaller microcontrollers (like Arduino boards that communicate over USB rather than Ethernet). Eventually, Quigley suggests that ROS 2 will be small and light enough to run on the microcontrollers inside sensors and actuators themselves, simplifying real-time control.

ROS + Docker: Enabling Repeatable, Reproducible, and Deployable Robotic Software Via Linux Containers, with Ruffin White (Georgia Tech)

Every day, roboticists write code that helps their robots do amazing new things. And every day, this code remains virtually useless to anyone else, because outside distribution is such a hassle. This isn’t a problem that’s unique to robotics: distributing software in general is tricky to do reliably and well, since you’re never sure what kind of system your end user has. Robotics magnifies this challenge because of the unpredictably exotic mix of hardware and software that makes up a given robot doing a given thing at a given time, combined with the extraordinarily rapid pace of advancement. Given all of this complexity, how do you make code that’s portable and robust and useful to as many people as possible?

Ruffin White, a graduate research assistant at the Institute for Robotics and Intelligent Machines at Georgia Tech (and ex-OSRF intern), discusses how Linux containers can help manage some of these issues. A Linux container is a software package that lives somewhere in between a complete virtual machine and bare code. Using a service called Docker, you can wrap up code, distros, libraries, drivers, and all the other dependencies necessary for your code to function into portable containers that still use the underlying kernel on whatever they end up getting installed on. This allows the container to be very lightweight, while also providing adaptability to local infrastructure.

White gives three different demonstrations of how Docker containers can come in handy for robots in a ROS environment. In the first, he shows how in an educational context, you can use containers to provide a preset environment that can be safely experimented in without any risk. Second, for researchers, containers can allow you to easily test different algorithms, provides a way to publish code in a repeatable and reproducible way, and makes collaborative research much simpler. And finally, industry can take advantage of containers to deploy multiple nodes on different cloud services, or to manage entire swarms of robots at once.

If you want to give ROS a try inside Docker containers, the offical repo can be found at https://hub.docker.com/_/ros/.

The rest of the videos from the conference can be found here.

If you enjoyed reading this post, you may also enjoy reading: 

• ROSCon 2015 recap and videos – part 1

Cybathlon provides a platform for the development of novel assistive technologies that are useful for daily life. There are races for athletes with powered arm and leg prostheses, for those wearing a robotic exoskeleton, and for powered wheelchairs. There’s also a race for cyclists using electrical muscle stimulation and a brain-computer interface race.

On the day, there will be experts and moderators to present the events along with hands-on-demos so that visitors can try out some of the technologies on show at Cybathlon.

Through the organisation of the Cybathlon, we want to remove barriers between people with disabilities, the public and technology developers.

Hardware experiments on motion planning for the the ballbot Rezero using direct transcription. Source: ADRLab ETH/youtube

When you walk across a room or down a path, your brain is making thousands of decisions on how best to move. For example, how best to use your weight, scanning for any obstacles or uneven surfaces, and how rigid (or soft) your limbs and joints should be. Teaching a robot to conduct the same decision-making process is ongoing in robotics, and a team from ADRL, ETH Zurich and NCCR Robotics is studying existing direct transcription methods for trajectory optimization applied to robot motion planning.

Rezero, the dancing ballbot. Source: ETH Zurich.

Using a method of control called direct transcription (where complex mathematical problems are broken down into smaller problems and each solved individually), the team uses direct transcription to enable an unstable ball-balancing robot to perform a series of tasks with increasing complexity. The common issue with direct optimisation methods, which are used to allow the robots to obtain more natural movements, is that they require computers to continuously run multiple algorithms at once, meaning that planning a path in real time, like the human brain does, has not yet been achieved. Simply put, the computers working online with a robot are nowhere near as fast, efficient and robust as your brain, and that’s before considering how heavy such a computer might need to be, or how much bandwidth this communication requires.

First, by using computer models, the team tested the unstable ball balancing robot (see video below) with three variations of a simple task where the robot had to move from one location to another while avoiding fixed obstacles. By allowing the robot to use the best solution it found for previous tasks, coupled with a feedback controller to stabilise the system, the simulated robot was able to find a path through two obstacles in under a second. When using the real robot, the same paths and trajectories were followed, with the robot reaching the planned destination safely and in the same period of time as the virtual robot, thus validating the hypothesis.

The speed with which the robot is able to assess its scenario and follow a path that it has decided for itself without falling is a positive step forward that can be transported onto more complex robots (such as quadrupedal robots) in more uneven environments.

If a quadrupedal robot, such as HyQ or StarlETH, are able to understand obstacles in its path and successfully avoid or modify a movement to accommodate, such as softening joints when walking over rocks, then robots have made one step further towards regularly being sent to disaster zones to locate victims and save more lives.

Welby Altidor, Executive Creative Director of Creation, Cirque du Soleil (L) and Benjamin Dupont (R). Source: 2016 NYCDFF

SPARKED: A Live Interaction Between Humans and Quadcopters won the 2016 New York City Drone Film Festival (NYCDFF) Featuring Drones category.

NYCDFF is the world’s first event exclusively dedicated to celebrating the art of drone cinematography. The festival offers an international platform for filmmakers from every corner of the globe to exhibit their work in front of industry professionals and the drone cinema fan community. 

Watch their award winning film here:

Cirque du Soleil, ETH Zurich, and ETH spinoff Verity Studios partnered to develop the short film that features 10 quadcopters in a flying dance performance. The collaboration resulted in a unique, interactive choreography where humans and drones move in sync. Precise computer control allows for a large performance and movement vocabulary of the quadcopters and opens the door to many more applications in the future.

You can also watch a short film about the making of SPARKED here:

If you like this post, you also may also enjoy reading:

• New quadrocopter video points to a future for flying machines in entertainment
• Quadrotors vs CGI: A Q&A with the makers of Sparked

ANYmal walking. photo source: ETH Zurich, RSL

ANYmal is a quadrupedal robot designed for autonomous operation in difficult terrains. It is capable of running and climbing, and with its incorporated laser sensors and cameras, the robot can perceive its environment to continuously create maps and accurately localize.

Following the successes of StarlETH, ETH Zurich’s bioinspired walking robot, Marco Hutter (RSL, ETH Zurich and NCCR Robotics) explains how ANYmal has been upgraded and why this robot is important for search and rescue platforms.

And here you can watch the AnyMal robot in action:

Most of D’Andrea’s work shown at this latest demonstration is dedicated to pushing the boundary of what can be achieved with autonomous flight. One key ingredient is localization: To function autonomously, robots need to know where they are in space. Previously his team has relied on an external high-precision motion capture system available in his Flying Machine Arena at ETH Zurich for positioning. In his previous TED talk on robot athletes for example, you can clearly see the reflective markers required by the motion capture system. This meant that most algorithms were difficult to demonstrate outside the lab. It also meant that the system had a single point of failure (SPOF) in the centralized server of the mocap system — a highly problematic point for any safety critical system.

In another world first, Raff and his team are now showing a newly developed, doubly redundant localization technology from Verity Studios, a spin-off from his lab, which gives flying machines, and robots in general, new levels of autonomy. For the live demonstrations, all flying machines use on-board sensors to determine where they are in space and on-board computation to determine what their actions should be. There are no external cameras. The only remote commands the flying robots receive are high level ones, such as “take-off” or “land”.

The nature of this performance was also unprecedented in that it did not use safety nets to separate the audience from the action, and in that it even saw dozens of vehicles fly directly above the audience.

The performance included demonstrations of various safety systems for flying machines, including a large, high-performance quadcopter that is fully redundant and that utilizes a state-of-the-art failsafe algorithm (see previous Robohub article) among its many other onboard and offboard safety features.

Following extensive technical discussions on the various failure modes of the positioning system and of each flying machine as well as on the systems’ numerous redundancies and safety features, the organizers of TED had full faith in the systems’ safety and reliability. So much so that they decided to indemnify the venue against any lawsuits to overcome its ban on drones.

Here is the video:

And here is a more in-depth breakdown of what you are seeing, based on a transcript of the presentation and information from Raff D’Andrea’s team:

Intro video – Institute for Dynamic Systems and Control (IDSC), ETH Zurich

The video shows some of the previous work of D’Andrea’s group on aerial construction: A 6-meter tall tower built out of 1500 foam bricks by four autonomous quadcopters over a three day period in front of a live audience and a rope bridge built by three autonomous quadcopters in the Flying Machine Arena.

Live demo 1: Tail-Sitter – IDSC, ETH Zurich

The Tail-sitter. Photo: Bret Hartman / TED

“This is a so-called tail-sitter. It’s an aircraft that tries to have its cake and eat it: Like other fixed wing aircraft, it is efficient in forward flight, much more so than helicopters and variations thereof. Unlike most other fixed wing aircraft, however, it can hover, which has huge advantages for take-off, landing, and general versatility. There is no free lunch, unfortunately, and one of the challenges with this type of aircraft is its susceptibility to disturbances, such as wind-gusts, while hovering. We are developing control architectures and algorithms that address this limitation. [Pushes the vehicle, then grabs it and throws it] The idea is to allow the aircraft to autonomously recover no matter what situation it finds itself in. [Second throw] And through practice, improve its performance over time. [Third throw, violently spinning the vehicle]”

Demo 2 (video of demo the night before): Monospinner – IDSC, ETH Zurich

The Monospinner. Photo: Marla Aufmuth / TED

“When doing research we often ask ourselves abstract, fundamental questions that try to get at the heart of a matter. One such question: What is the minimum number of moving parts necessary for controlled flight? This line of exploration may have practical ramifications; take helicopters, for example, which are affectionately known as “machines with over 1000 moving parts all conspiring to cause bodily harm”. Turns out that decades ago skilled pilots were flying RC airplanes with only 2 moving parts: a propeller and a tail rudder. We recently discovered that it could be done with only 1.”

“This is the monospinner, the world’s mechanically simplest, controllable flying machine, invented just a few months ago. It has only one moving part, a propeller. There are no flaps or hinges, no control surfaces or valves, no other actuators. Just one propeller. Even though it is mechanically simple, there is a lot going on in its electronic brain to keep it stable and move through space in a controllable fashion. Even so, it does not yet have the recovery algorithms of the tail-sitter, which is why I have to throw it just right.”

Live demo 3: Omnicopter – IDSC, ETH Zurich:

The Omnicopter. Photo: Bret Hartman / TED

“If the monospinner is an exercise in frugality, this machine here, the omnicopter, with its 8 propellers, is an exercise in excess. What can you do with this surplus? The thing to notice is that it is highly symmetric, and as a result it is ambivalent to orientation. This gives it an unprecedented capability: It can move anywhere in space, independently of where it is facing, and even of how it is rotating. It has its own complexities, mainly due to the complex, interacting flows of its 8 propellers. Some of this can be modeled, while the rest can be learned on the fly. [Omnicopter takes off, manoeuvres around the stage, lands]”

Live demo 4: Fully redundant multicopter – Verity Studios

Fully redundant quadcopter. Photo: Ryan Lash / TED

“If flying machines are going to find their way into our daily lives, they will need to become extremely safe. This machine here is a prototype being developed by Verity Studios. It actually consists of two separate, two propeller flying machines, each capable of controlled flight. One wants to rotate clockwise, the other one counter clockwise. When all systems are operational, it behaves like a high-performance, 4 propeller quadrocopter. [Quadcopter takes off and flies an arc across the stage] If anything fails, however – propeller, motor, electronics, even a battery pack – it is still able to fly, albeit in a degraded way [One half of the quad is de-activated, the quadrocopter starts to spin and fall, the failsafe mode kicks in and the quadrocopter recovers, flies to the back of the stage, and performs a controlled landing at the takeoff spot].”

Live demo 5: Synthetic swarm, 33 small flying machines – Verity Studios

Photo: Bret Hartman / TED

“This last demonstration is an exploration of synthetic swarms. The large number of coordinated autonomous entities offers a radically new palette for aesthetic expression. We have taken commercially available micro-quadrocopters, each weighing less than a slice of bread, and equipped them with our localization technology and custom algorithms. Because each unit knows where it is in space and is self-controlled, there really is no limit to their number. [Swarm performance]”

Raffaello D’Andrea wrapped up with: “Hopefully these demonstrations will motivate you to dream up new revolutionary roles for flying machines. For example, the ultra-safe flying machine [points to the fully redundant multicopter] has aspirations to become a flying lampshade on Broadway. The reality is that it is difficult to predict the impact of nascent technology. And for folks like us, the real reward is the journey, and act of creation. It is also a continual reminder of how wonderful and magical the universe we live in is; that it permits clever, creative creatures to sculpt it in such spectacular ways. The fact that this technology has huge commercial potential is just icing on the cake.”

More photos for your viewing pleasure:

Photo: Bret Hartman / Ryan Lash / TED

Photo: Bret Hartman / Ryan Lash / TED

Photo: Bret Hartman / Ryan Lash / TED

Photo: Steven Rosenbaum / Waywire

Testing knee perturbator. Photo source: ETH Zürich, RELab, Stefan Schneller

When designing exoskeletons for rehabilitation of patients after spinal cord injury or stroke, a constant concern is creating them to be as natural as possible to best enable user training to rebuild both muscles and neural networks.

Stefan Schrade from the Rehabilitation Engineering Laboratory, RELab, at ETH Zurich and NCCR Robotics, Switzerland, explains how the ETH knee perturbator is exploring the mechanical properties of the human knee and also helping understand how we recover from everyday stumbles.

And here’s a video of one of the experiments.

Design process

As a starting point we derived a physical model of the flying machine, which helped us to understand the behavior of the system. For instance, as the electric ducted fans are placed farther away from the center of the vehicle, the lever arm of the thrust vectoring system increases – but so does the inertia of the system. These are conflicting requirements for high maneuverability, where one seeks to maximize the lever arm, but still keep the inertia small. The physical model helped us to find a suitable tradeoff.

In parallel, the electric ducted fan and the thrust vectoring mechanism were characterized quantitatively by doing measurements on a separate test bench. In this way, the properties of the actuation – e.g. the total thrust, the time constants of the fan, and the thrust vectoring mechanism – could all be determined experimentally.

Figure 1: The test bench for characterizing the electric ducted fan and the thrust vectoring system.

The measurements on the test bench were used to update the physical model of the flying machine and to assess its flight performance in simulations.

Figure 2: Electric ducted fan with exit nozzle and control flaps.

Key Facts

Flying Platform Website

Researchers
Michael Muehlebach
Raffaello D’Andrea

Mechanical and electrical design
Michael Egli
Marc-Andrè Corzillius

Status
Ongoing research project

Hardware design and specifications

The analysis based on the physical model was used to determine the specifications of the hardware design. The three electric ducted fans (Schübeler DS-51-DIA-HST) were aligned on an equilateral triangle of 30cm side length. A carbon fiber honeycomb structure was used to connect the fans, and a 3D printed exit nozzle was mounted on each fan (see Fig. 2) in order to increase the airflow velocity and augment the thrust vectoring capabilities. The exit nozzle also integrated the two servos that actuate the control flaps. The flaps were optimized for a high stall angle using the XFoil software package (see https://en.wikipedia.org/wiki/XFOIL). Three aluminum feet support the structure when the Flying Platform is on the ground. In total it weighs 7.6kg.

Power is delivered by six 2-cell (or alternatively three 4-cell) battery packs that have a capacity of approximately 6.6Ah. The power consumption at hover is roughly 5.3kW at 120A. A PX4 flight computer is used to run the control algorithms. Each fan delivers a maximum thrust of 4.2kg, which results in a payload of approximately 3kg.

Research on control algorithms

The Flying Platform is used for benchmarking novel control strategies that account for actuation limits. In particular, the flaps are limited to a range of approximately 18°. Control algorithms explicitly accounting for this limitation can provide larger stability margins and other performance enhancements.

We are currently investigating model predictive control algorithms. The idea is to explicitly exploit the physical model of the system – including input and state constraints – for making model-based predictions. Since these methods are computationally expensive, we seek to trade off the prediction accuracy with computational cost, and quantify the consequences of such approximations.

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• Multiple tethered quadrotors performing high-g, high-speed formation maneuvers 

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Credit: ETH Zurich / Alessandro Della Bella

In 21 countries across the globe, hundreds of people are preparing for Cybathlon 2016, where cutting edge robotic assistive technologies will help people with disabilities to compete in a series of races. This summer the Cybathlon practice session took place at the Swiss Arena in Kloten so that the teams could test out the courses. Watch the trailer for the rehearsal games!

Cybathlon 2016 is organised by ETH Zurich and will showcase six disciplines:

• BCI Race Functional Electrical Stimulation (FES) Bike Race
• Powered Arm Prosthesis Race
• Powered Leg Prosthesis Race
• Powered Exoskeleton Race
• Powered Wheelchair Race

The finals will take place on October 8, 2016.

Find out more at www.cybathlon.com

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• Noonee: The chairless Chair

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Robots can now teach each other new tricks

MIT Technology Review — Researchers at Brown University and Cornell have successfully transferred robot learning from a PR2 research robot to the industrial co-worker robot, Baxter.

The research — which builds on the Robobrain project — could enable different types of robots to learn from each other and adapt quickly to new situations.

Ashutosh Saxena, who led the development of TellMeDave and RoboBrain, said that robots will increasingly share information in the future. “We are trying to make robots to learn and share knowledge,” he said. “Different robots can push and pull knowledge from the [RoboBrain] database.”

The key challenge in transferring learning between the robots at Cornell and Brown was that they are physically completely different, which means that low-level commands, such as those specifying the position each joint needs to assume in order to reach for a mug, will not match.

Collaborative robotics brings the best of existing human and robot capabilities together. However, if robots could collaborate among themselves and also with humans, we could be looking at rapid increases in robot capabilities in a very short time frame.
 
 

Robot builder designed for construction sites

Reuters — Meet the In-situ Fabricator: an autonomous brick-laying and construction robot that can adapt to “unplanned circumstances” such as dropped tools and sudden design changes.

As Reuters reports:

Matthias Kohler, of ETH Zurich (Swiss Federal Institute of Technology in Zurich), is one of the supervising professors on the research team. According to Kohler, who is also an architect, it is “the first machine that can actually go on construction sites and build non-standard designs, meaning designs which can vary and adapt to the local conditions directly in the building site”.

Leeds could become the first ‘self-repairing city’ with a fleet of robotic civil servants 

Digital Trends — Leeds could become a “self-repairing” city serviced by a fleet of robotic infrastructure inspectors and utility workers. The £4.2 M ($6.5 M) government-funded project is expected to incorporate drones and eventually terrestrial repair bots to take care of the English city’s needs:

Leeds’ robot fleet will focus on robotic fixes for citywide issues like burst or damaged utility pipes, broken or nonfunctional street lights, and road fractures that disturb drivers on their way to anywhere.

Three main branches of the project cover the functions of the Leeds robots: Perch and Repair; Perceive and Patch; and Fire and Forget. The Perch and Repair segment covers research into robotic drones that can land, or “perch” like birds atop tall structures like street lamps or building-mounted civil structures.

The Perceive and Patch team leads research into drones that can survey popular roads or even particularly dangerous ones in order to identify and repair potholes where they exist, and in the future, even prevent them before they occur.

Finally, […] Research into Fire and Forget would handle inspection and metering jobs for utility lines, theoretically including all gas, water, and electricity networks throughout the city of Leeds. These robots would also be able to perform repairs, although much of their function would most likely be focused on reporting, with the goal of avoiding repairs.

L.A. Authorities seek owner of drone that took out power lines in West Hollywood 

Hollywood Reporter — Yet another example of why we need drone regulation:

Los Angeles authorities are determining how to move forward after someone flew a drone into power lines in West Hollywood on Monday, knocking out electricity for roughly 200 customers.

“This is a first, but it will probably start happening every day,” said Sgt. Dave Valentine of the L.A. County Sheriff’s Department.

While we’re on the topic of drones, check out Routledge’s Global Affairs journal online, which has made some excellent articles about armed drones available for free viewing and download, including: Why and how the EU should act on armed drones and Drone warfare and morality in riskless war.

This Is A Tipping Point: Robots “Cheaper Than Any Human Worker” Means The End Of Jobs

Activist Post — It’s easy to be dismissive of some of the more dystopian visions of our robotic future, especially when some people have vested interests in painting the worst picture imaginable.

At the same time, it would be imprudent to pay no attention whatsoever to how the debate around robotics is playing out in different social groups, no matter how eccentric it appears. Fail to prepare for the forthcoming debate, as the saying goes… and prepare to fail.

Take prepper website “Activist Post”, for example, which ran a no-holds-barred robopocalyptic piece recently on human labor replacement as a result of robotics:

Before future-history brings us a dark and grim reality pitted against a killer Terminator
robot army, humanity will have to face job killing robots.

And that may be the bloodiest period of human history, after unemployment leads to riots,
unrest and bitter aftermath scenarios play out as a consequence.

Robotic labor is now literally cheaper than human labor, and it is poised to undercut work
forces and drive layoffs in even in the most exploitative, slave-wage factories in the world.

Sheesh. So, what’s the bad news?

It’s important for the robotics community to counter these dystopian visions by highlighting not just the business efficiencies robotics can provide, but also the great benefits, enhanced capabilities and opportunities robots can bring to existing workers.

Stuart Russell on Why moral philosophy will be big business in tech

KQED — As robots and AIs proliferate, the discussion about how these devices can make ethical decisions becomes more and more important.

With that in mind, it’s not surprising that at least one AI expert believes that moral philosophy is about to become a key topic of interest for robot and AI developers:

“In the future, moral philosophy will be a key industry sector,” says Russell.

Translation? In the future, the nature of human values and the process by which we make moral decisions will be big business in tech.

And he says, not to be flippant, but nobody’s going to buy a robot that cooks a cat. So it’s just a matter of time before tech companies, universities and the government starts pouring resources into programming robots with morals.

“In some sense [the robots’] only purpose in existing is to help us realize our values, and perhaps it’ll make people better,” says Russell.

Listen to the full interview with Russell here: https://soundcloud.com/thecaliforniareport/big-think-moral-philosophy-as-big-business

And finally…

Toshiba unveils trilingual robot in Odaiba — Japan Times

‘Whalecopter’ drone swoops in for a shot and a shower — Science News 

What Dancing Lizards Can Teach Us About Human-Robot Interaction — MIT Technology Review

A giant robot sentry guards the territory of Zaqistan — Sky News 

Scientists Connect Brain to a Basic Tablet—Paralyzed Patient Googles With Ease (SingularityHub); ‘Spring-mass’ technology heralds the future of walking robots (ScienceDaily); Interactive Performance Art/ificial Intelligence — Robotic Ape Comes to BAM (Huffington Post); Drones vs. driverless cars: A tale of two robotics policies (MarketWatch); PANERA CEO: Robots will replace our labor ‘like the sun comes up in the morning’ (Business Insider); Blood, Sweat, Tears, and Cheers (Georgia Tech).

Precisely controlled elastic actuators allow for temporary energy storage – in fact this robotic system consumes 10 times less power than other hydraulic systems. Weighing in at just 26 kg, it can be handled by a single operator, but operates autonomously at a speed of 2km per hour walking or running. Potential applications for such a highly mobile robot include: inspection of industrial, construction, or polluted environments, search and rescue operations, security, or even the entertainment industry.

Further reading:
http://www.leggedrobotics.ethz.ch/doku.php?id=robots:starleth:starleth
http://www.leggedrobotics.ethz.ch/doku.php?id=robots:scarleth
http://www.leggedrobotics.ethz.ch/lib/exe/fetch.php?media=robots:starleth:description:201401_descriptiontransporter.pdf

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In-situ fabricator. Source: NCCR Digital Fabrication

Digital fabrication enables the seamless combination of digital design with physical construction processes. To fully exploit this emerging technology within architecture, robotic fabrication must be expanded in prefabrication, but also fully implemented directly on construction sites. Achieving in-situ fabrication using mobile construction robotics is the goal of several research projects within the National Centre for Competence in Research (NCCR) Digital Fabrication.

In order to be able to work on a construction site a robot must be:

• mobile
• robust
• precise
• aware of its position on the construction site
• and able to adapt to uncertainties

These issues have already been subject of previous research including a recently completed doctoral thesis by Volker Helm. This initial project executed at the Chair of Architecture and Digital Fabrication resulted in the “dimRob” platform; an industrial robot arm mounted on a mobile track system and powered by a diesel engine. The robot was able to move across different terrains, manipulate materials and tools for construction, and was also fitted with a scanning system to manage the construction tolerances. The functioning of “dimRob,” however, still required significant human interaction: The robot had to be driven, stabilized, and localized manually by an operator before being able to build.

A new interdisciplinary collaboration will take this robotic platform to the next level, with the long-term goal of transforming the platform into an autonomous robot – the “In-situ Fabricator.” This augmented system will reduce the need for manual input and should be able to accurately build complex structures to millimetre level construction tolerances, while simultaneously being able to deal with the uncertainties of a construction site.

Timothy Sandy, PhD student at the Agile & Dexterous Robotics Lab (ADRL), ETH Zurich, explains that “the system should rely solely on on-board sensing and computing.” This is the crucial distinction compared to its precursor and a significant developmental challenge. Together with his colleagues Markus Giftthaler, PhD student at ADRL, and Kathrin Dörfler, PhD student at the Chair of Architecture and Digital Fabrication, Sandy is part of the interdisciplinary project team formed within the NCCR Digital Fabrication. This research initiative, funded by the Swiss National Science Foundation (SNSF), enables interdisciplinary collaborations and projects that individual disciplines are unable to achieve alone.

The robot’s arm is equipped with a laser range finder. As the robot sweeps its arm, the laser measures points in space to generate a 3D map of its surroundings. This map is registered against an initial scan of the context in order to calculate the robot’s position. Source NCCR Digital Fabrication

“One of the big challenges in the past month was the development of a precise localisation system”, Kathrin Dörfler explains. This might sound trivial, but how can a mobile robot localize itself when it doesn’t have an external reference point on which to base its coordinate system? A first proof of concept of the localization system was demonstrated in March. The method uses a 2D sweeping laser rangefinder that scans the surroundings to generate a 3D map of its context. This map is then registered against previous scans of the space in order to calculate the robot’s position.

A similar scanning and measuring feedback loop is also used to cope with the tolerances of construction: by comparing the point cloud scans of the existing state of construction to the CAD model of the structure to be built, the robot and its control systems are able to determine any small deviations from design and make adaptions within the construction process. “One of the shortcomings of previous robotic fabrication technologies, is that they are not linked to the design environments of architects,” says Dörfler, explaining the value of this technology to her profession. By linking the CAD systems used by architects with the technologies that build, there is a stronger understanding of what is possible and how to use the technology creatively.

Patches of bricks for assembly are automatically generated according to the robot’s location and range constraints. Source: NCCR Digital Fabrication

All of this sounds as if the “In-situ Fabricator” is ready to go on site tomorrow. However, according to the researchers, the technologies and processes are still “primitive” for now. Sandy explains: “At the moment the robot can be considered to be ‘working in the blind.’” This means that, after having moved, it isn’t aware of its position anymore, and first has to localize itself again. “In future the robot should be continuously aware of its position, even when in motion, and capable of steady, and accurate construction.” Only then will the seamless combination of the digital design with the physical construction process be entirely achieved.

Rock Print, Architectural installation at the Chicago Architecture Biennial 2015 from Gramazio Kohler Research, ETH Zurich and the Self-Assembly Lab, MIT

Inspired to take 3D printing technology to new heights, ETH Zurich and MIT researchers create “Rock Print” — a full-scale architectural installation on display at the Chicago Architecture Biennial until January 3, 2016.

Standing over 13 feet (4 metres) high in the Chicago Cultural Center, the monolithic Rock Print installation with its rough and elegant contours confirms that collaboration inspires “State of the Art Architecture” – the theme of the inaugural Chicago Architecture Biennial.

Born out of a 2012 University of Chicago conference that brought architects, engineers, material scientists, and physicists together, Rock Print demonstrates a principle called “jamming” that refers to aggregate granular materials, like gravel that are quite literally crammed together in such a way that they hold their form and shape like a solid, even though their molecular properties are closer (in terms of behaviour) to a liquid substance.

“Jamming” together, researchers from Gramazio Kohler Research, ETH Zurich and Skylar Tibbits’ Self-Assembly Lab at the Massachusetts Institute of Technology (MIT) produced, Rock Print – a zero waste and fully reversible architectural installation for the inauguration of the Chicago Architecture Biennial that opened on 3 October 2015.

Inspired by 3D print technology

“Rock Print is a proof of concept that takes current robotic fabrication technology and applies it to a full-scale architectural project,” said Andreas Thoma, ETH Zurich.

Petrus Aejmelaeus-Lindstroem, lead researcher for the project at ETH Zurich added, “The project shows the capacity of a 3D printing process to create a geometrically-complex construction using two simple components found in everyday life – string and rocks.”

The environmentally conscious ETH and MIT installation team used a custom robotic fabrication setup to lay down nearly 5 miles (9.1 km) of a recycled textile string in a complex pattern guided by a specifically designed algorithm. Like making lasagne, the string is alternated with layers of a loose standard concrete aggregate (rocks) from the Swiss company Misapor. The company makes self-insulating concrete using crushed glass, additives, and a heating process that expands the glass into a foam-like aggregate of mostly air.

While the foam glass is a fraction of the weight of conventional gravel aggregate, Rock Print weighs in at slightly less than one tonne (970 kg to be exact). The weight is a delicate balance – a lighter weight material is necessary for an indoor installation, but the structure of the installation depends on weight to provide strength to the compressional forces that maintain its shape and to compensate for the relatively weak tensional forces.

New possibilities for the future of architecture

Matthias Kohler, who also serves as the Director of the National Competence Centre in Research (NCCR) Digital Fabrication, commented on how 3D printing technology may influence architecture in the future stating, “3D printing technology is an inspiration for the future of architecture as it brings together resource efficient additive building principles with new possibilities for design. Such technology enables production of complex forms and intricate details of building elements at a minimal cost. Today’s commercially available 3D printing technologies are not yet suitable for the scale needed for architecture or its economic and structural demands.”

The Rock Print installation challenges and expands the scope of 3D printing to an architectural scale by introducing robotic fabrication and the use of inexpensive, reconfigurable bulk construction materials. This approach attempts to open new possibilities for future architecture – using advanced digital fabrication technology to build with sustainable and locally available materials.

Kohler says, “There is still a lot of interdisciplinary research needed to fully understand and leverage future digital fabrication principles at a full building scale, but after ten intensive years of research in the field, I am positive that such new principles will not only lead to exciting architecture projects, but also to a new digital building culture – possibly to a socially relevant transformation of our built environment.”

Gramazio Kohler Research, ETH Zurich

The research group headed by Professors Fabio Gramazio and Matthias Kohler at ETH Zurich examines the changes in architectural production that result from the introduction of digital manufacturing techniques. The main focus is ground-breaking research into computational design, constructive systems and their synthesis through the use of novel robotic fabrication technologies. Lindstroem and Thoma indicated that Rock Print was made possible through the collaborative knowledge of architects, engineers, and computational physicists. Prof. Dr. Hans J. Herrmann and Dr. Falk Wittel from ETH Zurich’s Institute for Building Materials and Prof. Dr. Heinrich Jaeger from the University of Chicago consulted on the project.

Gramazio Kohler Research – Rock Print project page

Chicago Architecture Biennial 2015

Rock Print is on display throughout the biennial that runs through 3 January 2016 in the Chicago Cultural Center – the former public library across from the stunning Millennium Park in the heart of the city. Famous for its contemporary architecture and landmark skyscrapers, the Chicago Architecture Biennial celebrates with the theme, “State of the Art in Architecture” providing a platform for ground-breaking architectural projects and spatial experiments that demonstrate how creativity and innovation can radically transform our lived experience. It offers an opportunity to take stock of more than 70 architectural projects and experiments from 30 countries around the world. Rock Print represents the Swiss-US collaboration at the forefront of innovation in architecture.

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Transcript below.

In this episode, Audrow Nash speaks with Brad Nelson, Professor at ETH Zurich, about his research regarding micro and nano robotics. They discuss many of Nelson’s projects: retinal and heart surgery, crystal harvesting, and robots with simulated flagella for mobility.

The video below shows some of the research discussed during the interview.

Brad Nelson 

Brad Nelson has been the Professor of Robotics and Intelligent Systems at ETH Zürich since 2002, where his research focuses on microrobotics and nanorobotics. Fundamentally, he is interested in how to make tiny intelligent machines that are millimeters to nanometers in size.

He studied mechanical engineering at the University of Illinois and the University of Minnesota, worked as a computer vision researcher at Honeywell and a software engineer at Motorola, served as a United States Peace Corps Volunteer in Botswana, Africa, and then obtained a Ph.D. in Robotics from Carnegie Mellon University. He was an Assistant Professor at the University of Illinois at Chicago and an Associate Professor at the University of Minnesota before moving to ETH.

Links:

• Download mp3 (18.4 MB)
• Subscribe to Robots using iTunes
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• Link to the Muli-Scale Robotics Lab

Transcript

Audrow Nash: Hi, can you introduce yourself?

Brad Nelson: My name is Brad Nelson. I am a professor of robotics and intelligence systems at ETH Zurich. I’ve been there for almost 13 years now.

Audrow Nash: Can you give me the big picture goal of your research?

Brad Nelson: The focus of our research is micro and nano robotics. We’re trying to understand how to make machines as small as we can and, along the way, we develop fabrication techniques to manufacture them. We look at ways to make them move, we look at applications for them and try to put that all together. We try to move the technology from fundamental research into a spinoff, a clinical application or something we might license to another company.

Audrow Nash: Just how small are these machines?

Brad Nelson: We work on things that are millimeters down to nanometers in scale. One of the things we’ve worked on for several years now is a device we call an artificial bacterial flagella. It’s about the size of a bacteria, maybe 15 or 20 microns long. You could fit about three billion in a teaspoon. They’re very tiny, you put five of them head to head and they might be about the width of a hair.

These are the smallest things we can see with optical microscopes. But then we also do a lot of work on nano fabrication with nano wires and nano structures, where you can’t see them, even with optical microscopes, so we need electron microscopes. Some of these structures will go down to 30 nanometers in diameter. And then we have things we put in the eye that are perhaps a millimeter or two long.

Audrow Nash: What are some applications of those?

Brad Nelson: One thing we’ve been working on has been retinal surgery; ways we can deliver drugs to specific locations on the retina, to target diseases such as age related macular degeneration or diabetic retinopathy. We’ve also realized that some of the technologies are not just for moving micro robots, but can move small catheters and endoscopes that you might want to put into the body.

We also work on how we might guide, not just untethered autonomous machines but small endoscopes or catheters, into the heart or the brain.

Audrow Nash: Do you see applications outside of the medical field?

Brad Nelson: We do. Drug discovery is one. One of the methods for discovering drugs is to first develop models of proteins. In the human DNA, we know the atomic sequence of protein molecules but we still have to understand the structure.

In structural biology, one of the main methods used to determine the shape of these tiny little molecules is to isolate proteins and crystallize them – grow them into tiny crystals. We’ve developed some of our micro robotic technology to handle these tiny crystals and to automate the process of retrieving them from the “mother liquor” and place them on a loop. That device is then immediately freeze dried, with the protein crystal on it, and then put into a high-energy x-ray beam. The structural biologist can infer the shape from the x-ray diffraction pattern.

It’s a long process but nobody has been able to automate it, up to now, so we think we have a solution there.

Lately, we have also been thinking of ways we can use these devices to create a catalytic reaction to treat wastewater.

Audrow Nash: Catalytic reaction?

Brad Nelson: To photo catalyze pollutants, for instance, and take toxins that are in the environment and degrade them into harmless substances. The idea is to put micro robots into polluted water, to treat and clean it.

There are also sensing applications: we can put micro robots into an environment and look at what chemicals are there, what kinds of substances that we want to get rid of. So we can use them as sensors to monitor the environment.

Audrow Nash: To understand this a little bit better I would like to talk about a few of your projects. To begin with, controlling micro robots with five degrees of freedom, can you describe that?

Brad Nelson: One of the first challenges we have is how to make small things. There’s micro fabrication technology and we borrow from the semiconductor industry; to make small machines, it’s the same technology as for making computer chips.

The second problem is how to make these small machine move: what kind of technologies can you use? Is there some kind of chemical reaction? Can you use lasers to deliver energy? The community has kind of settled, recently, on the use of magnetic fields, so you generate fields externally with electromagnets.

Basically, you wrap a wire around some kind of an iron core and, as you generate the electric current around it, you can create weaker and stronger magnetic fields. By changing their strength, we can exert forces that work on these small devices if they’re made of magnetic material.

We first started doing this over a decade ago with just two degrees of freedom, making it move on a surface. Then we started working on three degrees, to make things move in the X to Y and Z coordinates and to rotate.

Then we turned to five degrees of freedom motion. We realized we were going to need several electromagnets for this. We did a lot of numerical simulations on a computer to understand where the best place to put these magnets was, and the best way to control them. We realized we needed at least eight electromagnets. We built a system we call the OctoMag, so that we can very precisely control the current in each magnet and move small things with it.

Audrow Nash: Why do you need eight electromagnets for five degrees of freedom?

Brad Nelson: That’s something that we never quite understood until just recently. One of my post docs is working with me on this. Looking at the math, he realized that we can actually prove mathematically that eight is the minimum. We knew people who built systems that only had six magnets and they were having issues.

Magnetic fields can generate a force or a torque on something. The torque is like a compass needle on a magnetic field; we always know it’s going to point to the north and align itself with the earth’s magnetic field. Just by taking our field and rotating it, we can get other things – the magnetic particles, structures and micro robots – to rotate too, to align with the field.

Forces are a little more complicated because they require a special gradient of the field. The field has to be getting stronger in a direction, so that the micro robot moves in that direction. It’s with this coupling that the math gets a little complicated; you see a dependency between how you generate the gradient and the magnetic field.

It means that, although with five degrees you might think you just need five electromagnets, you can’t generate obituary gradients and fields at the same time. You need to add more electromagnets, and the question is: what’s the minimum? For our problem, it happened to be eight. The theoretical results are about to appear online now. It’s fascinating. People have been trying to understand how fields are generated since the 1800s, the 1700s even, and we’re still discovering new things. I think that’s going to help spur us on to new ideas and ways of making small things move, which is really the ultimate goal of what we’re trying to do.

Audrow Nash: This technology has gone into your startups. In addition to using small robots for crystallography, can you talk a bit about having a viable business model in research for this? Did you begin the research with a plan to market it?

Brad Nelson: I became a professor in 1995, so 20 years ago. My goal then was just to do interesting research, write good, grand proposals to get funding and to publish papers that people wanted to read. I think we’ve been successful in that.

Then, along the way, we started to get interested in getting our technologies out into the real world and that is a tremendous challenge. It’s one thing to have a research result to publish and another to actually develop a technology that people want to pay money for and use, and to help improve peoples’ lives in some way.

As I’ve developed my research agenda over the past 20 years, I started to think more carefully about potential business plans that might make sense. In biomedical, it’s clear you need to have patents and to be aware of what the patent landscape is. Even now, with some of our Masters projects, we will often go and just look at what patents are out there in this area.

If somebody like Siemens or Phillips already has a patent in an area, it can block the technology. It doesn’t make sense to go down a route where somebody has the IP locked up and, even if you do develop the new technology, there’s no chance of getting it out. You start to think in terms of: can you own, or do you have the potential to own, some important intellectual property in the area and develop it. You also consider, as you’re working on things, what potential therapies might this benefit and does it make sense, from a business standpoint, to develop these therapies.

Audrow Nash: What do you mean by therapies?

Brad Nelson: Well, for instance, one of our startups is called Aeon Scientific. They took our technology and they’re starting to look at some uses for magnetic fields. They looked at a lot of different areas and one thing they realized is that, with the aging population, more and more people need a particular heart procedure to treat a condition called Atrial Fibrillation, where your heart doesn’t beat properly; the electric signals don’t propagate through the heart.

Audrow Nash: It’s too fast or too slow or irregular?

Brad Nelson: Too fast or too slow or it doesn’t synchronize properly and so electrophysiologists and cardiac surgeons have discovered that, if they do a little therapy within the heart, they can reset it. People see potential to help a lot of people, but that also means potential to make money. It takes a tremendous investment to get this technology into the clinic. To justify that investment, you’ve got to realize a return on it. For that therapy, it makes sense.

Another therapy we’ve thought about is bronchoscopy, putting some of these devices into the lungs, particularly in premature infants, and trying to see which portion of their lung might be collapsed. That’s a therapy we’re interested in. The business model isn’t so convincing there; people just don’t project the potential number of cases that would justify the investment. That’s one of the reasons you’ve got funding agencies to enable you to progress further.

Audrow Nash: You mean funding agencies that fund research that’s not as in demand?

Brad Nelson: They fund research where the business model may not be clear. Although there are benefits, business investors may not find it persuasive, but it’s certainly going to be able to treat patients. We try to balance the two. We’re always trying to weigh up the problems we’re working on, the ones that have the potential to make a big impact. There are a lot of ways to measure this. One of these is the business case.

Audrow Nash: Going back to steerable catheter design with Aeon Scientific. So, you insert a catheter and that goes in through the arm or the groin or the neck, correct?

Brad Nelson: It goes through the femoral artery, near the groin. It enters the right chamber and then you can move over into the left chamber. You can get into all four chambers with this.

Audrow Nash: It has a flexible end that you direct using similar principles to the five degrees of freedom of manipulating small devices?

Brad Nelson: Yes, so the end of the catheter – the last few centimeters – is very floppy. At the very end is a permanent magnet. We can control its position and its orientation in the heart very precisely. We use that to deliver radio frequency therapy to ablate, to create this transmural ablation to stop electric signals from passing though certain areas of the heart.

Audrow Nash: The permanent magnet that’s at the end of the catheter is much bigger than some of the previous work you’ve done. Does the control of these magnetic robots scale?

Brad Nelson: It tends to scale well, although that needs a bit of explanation.

Generally, as devices get larger, magnetic fields can scale more favorably. But as they get smaller, it’s different. Magnetic forces and torques are a function of the volume of the magnet. Whenever you have something that depends on volume, as it gets smaller that’s not good, because if something is a cubic meter and then goes down to 10 centimeters, the size is decreased by just a factor of 10, but the volume has gone down by a factor of 1000. You’re getting these incredible decreases in the forces you can generate, so then we have to rethink our strategies. That’s where we’re inspired by nature – bacteria, for instance. We look at why E. coli swim with a rotary motor and use a flagella.

Audrow Nash: Describe the flagella a bit.

Brad Nelson: When Howard Berg [a professor of physics and molecular and cellular biology at Harvard] was in Colorado in 1973, he discovered that some bacteria, like E. coli and salmonella, have this little flagella. It’s a hair-like structure. People would look at it under a microscope and they couldn’t tell exactly how it moved. What Howard discovered, which surprised a lot of people, was that there was actually a rotary motor on this bacteria. People were astounded by that discovery. It was the first example of rotational motion in nature.

Audrow Nash: So it moves forwards in a similar way as a screw into wood?

Brad Nelson: Yeah, it’s like a screw, so it rotates this hair, this flagella, into a kind of helix shape, like a coil, and it propels itself that way. There’s a lot of physics, a lot of biology about why this works so well at these scales, that’s fascinating. How did nature evolve this kind of a structure? That’s a wonderful question.

We looked at it and realized that we can’t build that motor. It’s about 45 nanometers in diameter and it’s got 30 or 40 parts that are made out of proteins. What we could make, using some recent developments in nanotechnology, is these tiny little screws. Then we realized, if we put little magnets on the screws and rotated that field, we could get them to turn just like the E. coli flagella do. So they started propelling themselves, moving in fluid. That was in about 2007. We were surprised how well it worked and, as we understood the physics and the mathematics in the fabrication issues behind it, it’s been a very thrilling, rewarding area of research.

We’re always discovering something new and we’ve recently published a couple of papers. In one of them we’ve put DNA on these structures and we’ve demonstrated that, as we swim them near cells, we can get the cells to take up the DNA and then do gene transfection and express these.

The DNA would be coded for a particular florescent protein, so then the cells would express it and we can watch the cells start to light up. It demonstrates that we can target individual cells and do gene transfection with them.

In another project we’ve taken 80,000 of these ABF – the Artificial Bacteria of Flagella. We took this huge swam and injected it into the peritoneal cavity of a mouse and we’ve tracked it swimming within it. That paper’s recently come out.

Audrow Nash: What applications are there in that?

Brad Nelson: What we’re trying to do is demonstrate how we could potentially load some kind of drug on to these, and then target a particular location in the body. We demonstrated that we can load DNA and do transfection, then we demonstrated that we can move swarms of them and target particular locations, in this case in a mouse. Then, eventually, the furthest steps would be putting some kind of a drug that may treat a condition on there, and trying to target some very specific location, maybe a tumor in the body, and getting them to swarm around it and deliver the drug in a very localized area.

Audrow Nash: What do you think is the future and timeline of micro and nano robots?

Brad Nelson: I really think the field has made tremendous strides in the past 10 to 15 years. There are so many interesting problems and so many results that surprise me. I certainly think that within the next decade we’ll see these devices in clinical trials.

If we’re looking at medical applications, the first people we have to get interested in this are the doctors, the people who are really going to use it. They have to understand what the potential is and they have to understand what conditions could be treated with it. They have to get excited about it and be willing to work with us on it.

The first thing is you get doctors involved. Doctors have spent some of their valuable time with us on this. It takes tremendous investment and resources to get these things pushed through, to get all the engineering done properly and the FDA regulations, or whatever medical regulations need to be followed. That means you need business people; you need investment, so you need to convince business people too.

You’ve got to bring together, not just the engineers and scientists, but also the medical doctors and the business side. That’s what always makes it difficult to predict exactly how long this will take. With the right resources we can move very quickly, but not everybody’s vision is in alliance, initially. I certainly hope and expect that within less than a decade we’ll see applications in the clinics. I think, with this kind of thing, once it gets going, more and more things – things we can’t see right now – will start to emerge. I’m very confident about that.

Audrow Nash: Thank you.

Brad Nelson: Thank you very much.

All audio interviews are transcribed and edited for clarity with great care, however, we cannot assume responsibility for their accuracy.

If you like this post you may also enjoy:

• Micro-robotics and medicine: Interview with Toshio Fukuda
• Minimally-invasive eye surgery on the horizon as magnetically-guided microbots approach clinical trials
• Better micro-actuators to transport materials in liquids
• Crowdsourcing new strategies for cancer treatment: Towards swarming nanobots
• Robots Podcast: Nanosystems

ETH Zurich, 2015.

Using quadrocopters and some rope, researchers have woven together a bridge strong enough to walk across.  Made at the ETH Zurich Flying Machine Arena in Switzerland, the bridge joins two scaffolds, and is the first full-scale load-bearing structure autonomously built by flying machines. The feat represents one more step in the field of robotic aerial construction [1, 2].

Except for the metal scaffolding at either end of the structure, the bridge itself consists exclusively of Dyneema rope, a tensile material with a low weight-to-strength ratio that makes it ideal for aerial construction. Weighing just 7 grams per meter, a 4 mm diameter Dyneema rope can sustain up to 1300 kg. The 7.4 m long bridge uses various rope techniques – knots, links and braids [3] – and has a total rope length of about 120 m.

How it works

The project was developed at the Flying Machine Arena [4], a research and demonstration platform for aerial robotics. The arena is equipped with a motion capture system that provides vehicle position and attitude measurements for the small custom quadrocopters. An offboard computer runs the algorithms and sends commands out to the flying machines via a customized wireless infrastructure.

Flying machines cooperate to create a braid and brace the structure together.

Before construction begins, the location of the scaffolding is measured and input to the system. Once the anchor point locations for the rope are known, all the connections and links of the bridge’s primary and bracing sections are — without human intervention — autonomously woven and secured into place by the quadrocopters, which are each equipped with a motorized spool that allows them to control the tension of the rope.

A quadrocopter equipped with a motorized spool for rope deployment.

A plastic tube guides the rope to a release point located between two propellers. The system estimates the external forces and torques exerted on the quadrocopter by the rope during deployment, and takes this into account in order to ensure that the quadrocopters behave as desired [5].

The researchers then walk across the bridge to demonstrate its load-bearing ability.

Once the bridge itself is constructed, stabilizers are added to make it easier for a person to cross. Because there are no sensors to detect the rope’s configuration, the locations of the narrow openings of the bridge must be measured and input to the system, which then adapts the quadrocopters’ trajectories in order to weave the stabilizers.

The team also developed a series of computational tools to help identify and design the kinds of novel structures that are buildable using flying robots. Using these tools, the researchers can simulate their designs, determine feasible construction sequences, and evaluate the structure before they begin building [6].

More information and related publications can be found on the project websites:

• http://www.idsc.ethz.ch/research-dandrea/research-projects/aerial-construction.html
• http://www.gramaziokohler.arch.ethz.ch/web/e/forschung/240.html

Credits

Aerial Construction is a collaboration between the Institute for Dynamic Systems and Control and Gramazio Kohler Research at ETH Zurich, Switzerland, 2015.

Researchers: Federico Augugliaro, Ammar Mirjan, Fabio Gramazio, Matthias Kohler, and Raffaello D’Andrea.

Related work

[1] F. Augugliaro, S. Lupashin, M. Hamer, C. Male, M. Hehn, M. W. Mueller, J. Willmann, F. Gramazio, M. Kohler, and R. D’Andrea. “The Flight Assembled Architecture Installation”, IEEE Control Systems Magazine, 2014

[2] A. Mirjan, F. Gramazio, and M. Kohler, “Building with Flying Robots”, FABRICATE: Negotiating Design and Making, 2014

[3] F. Augugliaro, E. Zarfati, A. Mirjan, and R. D’Andrea, “Knot-tying with flying machines for aerial construction”, IEEE/RSJ International Conference on Intelligent Robots and Systems, 2015

[4] S. Lupashin, M. Hehn, M. W. Mueller, A. P. Schoellig, M. Sherback, and R. D’Andrea, “A platform for aerial robotics research and demonstration: the flying machine arena”, Mechatronics, 2014

[5] F. Augugliaro and R. D’Andrea, “Admittance control for physical human-quadrocopter interaction”, European Control Conference, 2013

[6] A. Mirjan, F. Augugliaro, R. D’Andrea, F. Gramazio and M. Kohler,” Building a Bridge with Flying Robots”, Robotic Fabrication in Architecture, Art and Design 2016, in press

Article in preparation:

1. Augugliaro, M. Schulz, A. Mirjan, F. Gramazio, M. Kohler, and R. D’Andrea, ”Building a Rope Bridge with Flying Machines”

If you liked this post, you may also enjoy:

• Multiple tethered quadrotors performing high-g, high-speed formation maneuvers 
• Quadrocopter failsafe algorithm: Recovery after propeller loss
• Video: Throwing and catching an inverted pendulum – with quadrocopters
• Quadrocopters learn from prior experience to improve slalom flying

Transcript included.

In this episode, Audrow Nash speaks with Sergei Lupashin about Perspective Robotics’ tethered flying camera, the Fotokite Phi, which is currently crowdfunding on Indiegogo. The Phi is a portable light weight GoPro-carrying quadrocopter that flies without a vision system or GPS, and instead uses the tension on the retractable tether to determine where it is in space. According to Lupashin, the tethered leash provides a natural, easy-to-learn and accountable interface for controlling the Phi.

https://www.youtube.com/watch?v=aglTWdI-4Bo

Sergei Lupashin

Sergei Lupashin is the founder of Perspective Robotics, the Swiss company behind the Fotokite. Previous to that he worked in aerospace and participated in robotics competitions such as the DARPA Grand+Urban Challenges (autonomous cars). He was chief architect for the ETH Flying Machine Arena, where he enjoyed torturing little quadrocopters until they learned to do flips. He holds a BS in Elec & Comp Engineering from Cornell, an MSc + PhD in Mechanical Engineering from ETH Zurich (topic: aerial robotics) and is a TED Fellow. Sergei is passionate about building devices that are usable and useful in the real world.

Links:

• Download mp3 (14.3 MB)
• Subscribe to Robots using iTunes
• Subscribe to Robots using RSS
• Link to Fotokite Phi Indiegogo campaign

Transcript

Audrow Nash: Hi welcome to the Robots Podcast. Can you introduce yourself to our listeners?

Sergei Lupashin: I’m the founder of Perspective Robotics, a company based in Zurich, Switzerland that is behind the Fotokite, the Fotokite Pro and the Fotokite Phi.

Audrow Nash: Fotokite Phi is currently crowdfunding on Indiegogo. Can you tell me a bit about the campaign and its goal?

Sergei Lupashin: This is our first attempt at building a product for consumers. We started off by building the Fotokite Pro, which is a specialized, more expensive product designed to be used for broadcast. With the Fotokite Phi we have tried to make something much more accessible both in terms of price and usability. It’s extremely portable and it can be used in lots of different situations.

We are trying to raise a minimum of US $300,000 … It’s a hardware product, so you have to build critical mass to make it accessible for a wider audience. It’s a very exciting step for us.

Audrow Nash: Can you describe the Phi?

Sergei Lupashin: I’m holding one in my hands right now … It’s a small quadrocopter that holds a GoPro, and it weighs only 12 ounces – about the weight of a small can of soda.

What’s unique about it is that you control it via tether. You hold onto what is essentially a glorified dog leash with some electronics, and you launch the Phi just by turning it on, giving the quadrocopter a twist, and letting it fly.

Audrow Nash: This doesn’t have the same sensors as most drones. Of course it has an IMU, but you’ve removed GPS, correct?

It’s a different experience from traditional drones because the interface is so physical: you feel pretty much the smallest motions of the Fotokite in the air through the string.

Sergei Lupashin: Exactly. One of the things we use the tether for is to figure out where the Phi is relative to the user. A normal drone does that by having a GPS receiver or having some sort of machine vision to figure out where it is. In our case, we use a tether that is kept under tension at all times. By calculating where that tension force points, the Fotokite actually knows where it is relative to you.

This changes the dynamics of the system because it’s completely self-contained and the whole experience exists around the user. If you are walking down the street, hiking in the mountains or walking down a trail with this thing attached to you, it will naturally follow with you without any special algorithms.

Audrow Nash: Can you tell me a bit about the leash, how it works, how it keeps constant tension?

Sergei Lupashin: When it’s hovering it doesn’t fly straight up; it flies at a small angle and it stays not above you but to the side. The leash is spring-loaded, so the Fotokite produces a bit of extra force to keep the tether under tension.

You can just point the Fotokite in the direction you want to launch it, but once it’s flying, how do you tell it to turn? How do you tell it to move around? We wanted to get away from the concept of having to use a joystick or your smart phone to do that. Inside the leash are electronics that connect to the Fotokite while it’s flying; to control it you hold down the button on the side of the leash and you rotate your wrist. That motion of your wrist – that motion of the leash – is translated into a command for the Fotokite.

Audrow Nash: What kind of commands can you give? Can you have it rotate to look around?

Sergei Lupashin: Yes. Right now there are just two modes of interface. One mode is in-phase rotation. For example, if I want to take a panorama, I would launch the Fotokite straight up and then I would hold down the first button and rotate my wrist. The Fotokite would then rotate in place and capture the full 360 panorama. The other mode lets you control the position of the Fotokite relative to you.

Audrow Nash: The angle?

Sergei Lupashin: Exactly. We usually speak in terms of ‘elevation’ and ‘orbit’. For example, if you look at the stars in the sky, a star has a certain elevation above the horizon. To control the elevation in our case, holding down a button while you move your wrist up and down will move the Fotokite either from a horizontal position to a vertical one (relative to you), or vice versa. It basically controls the vertical angle where it flies.

Moving your wrist in the horizontal plane will cause the Fotokite to orbit, meaning that it will slowly reorient itself around you. If you keep doing this motion, the Fotokite will complete a circle around you at a given elevation.

You can get really neat matrix-style shots of yourself. Or you can use it to do sophisticated shots, using the Fotokite like a flying steady-cam.

Audrow Nash: How long does it take to train someone to use the Fotokite?

The beauty of the system is that there is nothing active in this tether, so you can attach any string to the Fotokite and it will still work just fine.

Sergei Lupashin: It’s a different experience from traditional drones because the interface is so physical: you feel pretty much the smallest motions of the Fotokite in the air through the string.

We did a number of demos for both expert drone users and people who haven’t touched one before. Getting it to fly is surprisingly straightforward: you show someone how to do it, they’ll repeat the motions, and it will work immediately.

To get really unique shots and smooth video requires a bit of skill. The nice thing is, with the tether, you can use your own physical movements to control it and to keep it from crashing into things. It’s a lower stress experience than what you see with traditional drones.

Audrow Nash: Speaking of crashing into things, what happens if it bumps into an object? Or if someone runs into the tether, the tether becomes taught in a different direction, and that tension is released suddenly?

Sergei Lupashin: In terms of bumping into things, we have protective coverings that extend past the motors, so most of the time an object would bump into the protective coverings first. That helps to prevent crashes, and it also helps to give the user confidence in being around the Phi.

In terms of the tether getting caught in things, the beauty of the system is that there is nothing active in this tether, so you can attach any string to the Fotokite and it will still work just fine.

For example, if you’re filming the rooftop of your house and you’re trying to get over to the other side of it, you can actually fly the Fotokite over the rooftop and then get it such that the tether touches the edge so you can sling-shot it over. It will simply use that new fixed point as the new reference point, and this happens naturally.

Explained in words it sounds weird, but just imagine flying a kite where the lift is generated by the kite itself: if you grab the kite string, and someone pulls it away, it will still fly at the same angle – but relative to that new point.

Audrow Nash: Does this mean that you don’t really need the smart leash? Is it just for controlling the Fotokite, so that it rotates and you can change the vertical angle?

Sergei Lupashin: The smart leash is there to make the system complete. Most folks just want to use the system to capture a picture or video. We didn’t want to make them have to go find a string.

The leash is a convenience: it’s nicely built, it has a spring, and it has electronics that allow control.

The Phi’s arms fold up with the propellers on the inside so that you can put it into its tube-shaped carrying case. It’s about the size of a thermos, and you fit it into your backpack.

I should also mention that the Fotokite Phi folds, because in real life, transportation is a major issue. The Phi is pretty unique in that it has a lock mechanism that makes a satisfying click when it locks. And when you unlock it, the arms fold up with the propellers on the inside so that you can put it into its tube-shaped carrying case. It’s about the size of a thermos, and you fit it into your backpack.

Audrow Nash: And everything fits in there?

Sergei Lupashin: Yes, the leash and everything.

Audrow Nash: The tether is very nice from the perspective of controlling the drone. What are some other advantages of using tethers?

Sergei Lupashin: The tether wasn’t actually the original idea.

I was finishing my PhD and looking at different schemes for aerial systems. This was in Raff D’Andrea’s lab – he has been on your podcast as well. We were exploring some different approaches using gestures – with Kinnect for example. But all of these systems were based on machine vision, which is incredibly sensitive to the conditions you are operating in. Sunrise, lens flare, darkness, water – all of these things confuse the system.

The tether completely changed the dynamics of the conversation between the operator, the vehicle and the public. It makes this device much more acceptable in public.

So the question was: how do we get localization and interaction in the most robust way possible? That’s where the idea of the tether came from: it was originally a technical solution to let a flying vehicle figure out precisely where it is relative to you, without relying on sensitive systems like GPS or machine vision etc.

Then, when we made the first demo, it turned out to be a really elegant way to interact with the system. The tether completely changed the dynamics of the conversation between the operator, the vehicle and the public. I think this was actually one of the most exciting moments of this process, because as a technologist you don’t foresee it; you see the tether as a technical solution and nothing else. But then it turns out to also have all of these facets that are not technical, but rather about the experience, and how people see the product.

In the end, the tether changes the Fotokite from being another drone into something that is more of a companion flying device. It’s a very personal device … it’s more like a kite, and people treat it that way.

One parallel is to imagine being at the park and having your dog on a leash versus not on a leash: for some people it’s fine, but other people just get freaked out by dogs that are not leashed. I think we see some of that with drones from a privacy perspective. What we found is that having a tether changes the conversation and makes this device much more acceptable in public.

Audrow Nash: There’s accountability because you can see where the operator is?

Anyone – no technical background required – intuitively understands the chain of responsibility with this device.

Sergei Lupashin: Exactly. Anyone – no technical background required – intuitively understands the chain of responsibility with this device.

Audrow Nash: Can you tell me a bit about how this and similar technology has been used in journalism, for example the Fotokite Pro?

Sergei Lupashin: The original inspiration for the Fotokite came from aerial footage of the Bolotnaya Square demonstrations in Russia in 2011. It was after the federal elections, and it was a big demonstration right in the center of Moscow. The footage was captured pretty much by pure chance from a drone – quite a big drone with an SLR camera. There was this one image, a panorama really … it’s amazing how well it transmitted the scale and atmosphere of the event.

The people who took that footage were very lucky that they happened to have the right equipment; they were professionals so they could do it safely, and they happened to have the right permissions. But we’ve seen many other examples where people haven’t been able to get these perspectives and cover events like this as well as they could have been covered. For example, in Ferguson, Missouri where there was a no fly zone was imposed, which many believe was done to keep the media out.

We also found out that having a physical connection usually changes the regulatory aspect. For example, in Switzerland and France, after some conversation with the regulators we were able to get special rules for tethered devices that are much more permissive than traditional drones. From a regulatory perspective, the usual thought process is focused on safety, whereas privacy is more universal and not usually what they are basing rules on. From a safety perspective, in Zurich for example, it was prohibited for a while to fly drones commercially. The Fotokite was allowed based on the tether and specifically based on the idea that the tether restricts the height of the device.

Many regulators think of how much energy would be dissipated if the device falls in an uncontrollable fall, and there is a magic number of 66 joules … if you fall and it dissipates 66 joules then you are magically unsafe.

Audrow Nash: How much is 66 joules?

Sergei Lupashin: This is potential energy, so it’s Mass X Gravity X Height. Imagine a 6 kg bowling ball falling from about a meter …

It’s a safety margin. With the Fotokite’s tether you can restrict the length of the tether and thus the height, so you can guarantee that under no conditions are you going to exceed that safety limit.

Audrow Nash: So you can only extend to the length of the tether unless you can’t get high enough to possibly generate 66 joules on complete impact?

Sergei Lupashin: Yes, that’s right.

There are other aspects they look at, too, like system robustness. For example, how many subsystems or how many components do you have in your critical loop? How many subsystems are there such that if one of them fails you have an uncontrolled system or a catastrophic failure? In a traditional drone, GPS is usually in that critical loop, as is your radio system, and if you lose your GPS or radio you will crash into something. With the Fotokite, there is no GPS and if the radio cuts out, it will just fly in the same position.

Audrow Nash: How does it look for other countries with these exemptions? For example, do you believe the US will permit tethered drones to fly? Do you think they will give exemptions similar to Switzerland and France?

Sergei Lupashin: It’s very hard to predict which way the US regulations are going to go right now. If you look at the history of it, just over the past few months regulations were proposed that were extremely lenient and permissive. Most recently there has been a massive push over certain events … you’ve probably heard of the person shooting drones down over their property. So it’s really hard to predict.

It’s a challenge since all of this technology is new and people don’t quite know how to differentiate it. For example, what is a tethered drone? If you attach a fishing line to a DJI, is it now tethered? I kid you not that there are commercial products out there for sale that offer exactly this, and they promise to get you around regulations.

We are trying to be proactive and come up with commonsense and observable definitions of what it means to be tethered.

We are trying to be proactive and come up with commonsense and observable definitions of what it means to be tethered. For example, I really believe that the tether has to be loadbearing, meaning that under typical flight it should actually be under tension, and it should be rated for some sort of tension that responds to the vehicle.

Audrow Nash: For a hobbyist or someone that just wants to use the Fotokite Phi to take pictures of themselves, do these regulations mean anything outside of countries that have exemptions for tethered drones? Or is it only for commercial use and journalism that the regulations apply?

Sergei Lupashin: Regulations generally apply to commercial use, but there are exceptions specifically generally cities, populated centers, and in the US national parks. If you go for a hike to the Yosemite or Yellowstone National Park in the US, for example, you can’t use a drone right now. These are the kind of the frontlines where we’re going to see how consumer drones get regulated in the future.

Audrow Nash: Going back to the Phi, how does the tether affect battery life?

Sergei Lupashin: In the Pro we use the tether to supply power, so we can fly forever. In the Phi we couldn’t do that because of cost and complexity, so we use a standard one-port battery. The trick there is that, since you’re producing extra tension to keep the tether taut, you are wasting a tiny bit of battery life, but on the other hand, if you imagine how a kite actually uses the wind, you could be using a less than normal power to stay afloat.

The current prototypes fly for around 7-10 minutes. For the production units, we are aiming for 15 minutes of typical flight time. The battery is swappable in the field, so you always have the option of replacing it.

Audrow Nash: How did you decide to move from a journalism drone – the Fotokite Pro – to a consumer drone with Fotokite Phi?

Sergei Lupashin: With the Fotokite Pro we realized after talking to existing drone users that the tether has a unique advantage especially in the niche of live reporting. In journalism you typically want to operate next to people and next to something that’s happening, and you don’t want to add tension to that situation. It’s a very unique niche where the tether makes a huge difference. The powered tether is important because journalists can keep the device afloat and not worry about battery life.

But we always wanted to build something a wider reach, and a few months ago we finally decided it’s now or never, because everything is developing very quickly. The Phi is is a big experiment for us to see how well we can use the tether to build a new user experience.

A lot of people see the Phi for the first time and they think it’s just a quadrocopter on a string, but the deeper story is to look at the engineering behind it, using the tether as a different interface approach.

A lot of people see the Phi for the first time and they think it’s just a quadrocopter on a string, but the deeper story is to look at the engineering behind it, using the tether as a different interface approach.

Audrow Nash: Is this a way of addressing the interaction bottleneck with robotics technology?

Sergei Lupashin: That’s right. Have you tried reprogramming your alarm clock lately? [laughs]

In robotics labs we tend to come up with ridiculously complex systems. I’m sure they can do a lot in principle, but they are very difficult to interact with. I think this somehow echoes with many robotics products that have already come out. An example of that is in Japan when the Fukushima incident happened. Arguably Japan has some of the most advanced robotics, especially for search and rescue, anywhere in the world. But they really struggled to make a difference in that situation. And I think a lot of problems are because of interaction, because of training, and because of the complexity of the systems.

The inspiration for the Phi is really to try to cut across that and come up with a smooth and low-friction user experience, where even someone who has never touched robotics could be shown how to use this device and they could naturally take it, use it themselves, and feel confident and empowered by it.

Audrow Nash: Thank you.

Sergei Lupashin: Thank you.

All audio interviews are transcribed and edited for clarity with great care, however, we cannot assume responsibility for their accuracy.

Professor Robert J. Flatt. Source: DFAB

Being able to control the moment when concrete turns from liquid to solid is crucial for digitally fabricated concrete structures. The timing of this process can be controlled by tuning the chemistry and adding small amounts of specific substances at just the right time. Robert J. Flatt, Professor of Building Materials at ETH Zurich, discusses this process and the innovations in concrete chemistry and digital fabrication he and his team are working on to reduce the environmental footprint of the most used building material in the world.

“Test the limits and break through (…) no rules for me (…) let it go!”, you used this song from the Disney film “Frozen” in a presentation on your research. How are you working to get rid of rules?
I’d rather say: We try to do things that, at first, seem unfeasible. Lets take the making of a cake as an analogy. In general you have dough, which is fluid. You pour it into a mould and then put it into the oven to harden. What we are working on is similar to a process that would extrude this dough and have it immediately shaped and cooked. You could say: We are trying to remove steps of common processes by forcing the material to behave differently.

“The key is to use the critical moment when the material transforms from liquid to solid.” What does this mean in practice?
We are working on what I call the “spices” of concrete. Added to a mixture in very small amounts, these additives have a huge impact on the material properties. I give you an example. The research project “Smart Dynamic Casting” (SDC), a collaboration with the ETH Chair of Architecture and Digital Fabrication, started with the question: Can you make complex shapes of concrete without any formwork? SDC is an answer to this challenge, in which the key is to be able to use the critical moment when the material transforms from liquid to solid; when you can shape the material, but it doesn’t collapse under its own weight.

SDC also has been your first collaboration in the field of digital fabrication, before joining the National Centre of Competence in Research (NCCR) Digital Fabrication. Where are the synergies between material sciences and digital fabrication?
Digital fabrication in concrete wouldn’t work without the manipulation of the material properties. You either would end up with a very inefficient process or the process would simply fail. On the other hand, robotic control opens new perspectives to surpass current state-of-the-art construction processes, particularly for more individualized structures. For me this interdependency of material design and robotic processes is the exciting part about this research field, and bringing our expertise to this collaboration is where we see our role within the NCCR Digital Fabrication.

“A big opportunity is to combine the manipulation of the material properties with the reduction of the environmental footprint.” What is the added value of these new fabrication processes and materials compared to traditional ways of building?
If you take SDC, the overall interest was to be more efficient in producing complex shapes. So the added value is about creativity and efficiency. Furthermore, by replacing traditional formwork with a single adjustable slip-form, waste can be reduced. However, in terms of the overall environmental impact I consider the elimination of the formwork to be of second order. A much bigger opportunity is to combine the manipulation of the material properties with the reduction of the environmental footprint of concrete. Accordingly, the development of more environmentally friendly types of concrete is one of our main research focuses and also one of our major long-term goals, of which we plan to feed the results into the NCCR Digital Fabrication.

5 to 8% of the man made CO2 emissions is effected by cement production. Why do you focus on concrete and not on a building material with less environmental impact?
Concrete is the most used building material in the world. It is used in larger quantities than all the other building materials added together [1]. There are basically no other materials available in the quantity that can compete with concrete in terms of performance, environmental impact and cost. This huge volume of concrete also means that: If you simply succeed in reducing the amount of cement used in concrete you have a huge multiplication factor. As an example: about 40% of Switzerland’s Kyoto Protocol objectives where reached by the cement industry. Part of this reduction is due to the fact, that less concrete was used, part of it due to improvements in production, and part due to changes in the nature of the cement being produced. That brings us back to the “spices”; these additives can be used to tune the material properties, but you also can use them to keep required values of some properties while changing the proportions of the materials you used. As an example; chocolate producers are now allowed to replace 5% of the cacao fat with vegetable oil, but of course they don’t want to change the taste. In our research we try to do the same, but our goal is not to replace 5%, but 50% of the material. To accomplish this we need to formulate very good spices for it to go unnoticed!

In your experience, what factors are required for a research innovation so that industry will take interest?
An innovation, of course, needs a market perspective. In this sense environmental aspects are certainly a macro trend that impacts their long-term strategic considerations, however it is clearly the costs of materials, energy, and the impact of CO2 emissions that will influence marketability in the long term. The balances between impact issues and how to bring an innovation to market are definitively the high-level strategic considerations for industry.

So, if the NCCR Digital Fabrication wants to be successful, in practice it should focus on environmental issues?
This conclusion is too limited and brief, whereas the goals of the NCCR Digital Fabrication are long-term. I would rather describe the process as such: In the first phase we are more in the logic of developing something like a Formula One car, a niche product. So, of course we are concerned with doing things in a sustainable way, but we are still addressing a small portion of the market. We are looking at opportunities with high added value, rather than large volumes where processes are much more optimized and margins are very tight. At this stage looking at the large volume market from the perspective of digital fabrication could be a killer for innovation. Then, in a later stage, we intend to evaluate which part of our innovations can be adapted to larger scale use. This is where we can optimally shift our attentions to larger issues such as sustainability. Once we have resolved the smaller scale problems we can shift to volumes that allow us to have a large-scale ambition and a large-scale impact to improve sustainability.

Are there any risks you can think of regarding the path on which this NCCR is heading?
If you want to build a Formula One car and you can build it more efficiently with a robot that has special features, you might well be persuaded to also use this very versatile robot for normal serial production, but this may not be the most optimal solution. The big question for me is: Will our increased use of digital fabrication eventually lead to automation with a loss of design individualization? This is, of course, exactly the opposite of what we are aiming to accomplish within the NCCR Digital Fabrication. So, to answer your question, I think it is our mandate to bring affordable “mass customization” into construction and to use our research to ensure that individualization of design and construction is available for everyone.

[1] Yearly volumes: concrete 10 km3, fired clay 2 km3, timber 1.3 km3, steel 0.1 km3.

On this subject see also the newspaper contribution “Gewürze für mehr Nachhaltigkeit” of 25.06.2015 in “Tages-Anzeiger” (in German only).

Flying Fotokite close up

Zurich-based robotics company Perspective Robotics this week unveils Fotokite Phi, their first consumer targeted, affordable, accessible, tethered flying camera. The Fotokite Phi is available now for pre-order on Indiegogo for $349 USD.

https://www.youtube.com/watch?v=aglTWdI-4Bo

The story behind Fotokite

Inspired by drone operators during the Russian protests in 2011, Perspective Robotics’ CEO Sergei Lupashin set out to make a drone that is safe and easy to use. The result is the Fotokite, a tethered user-friendly quadcopter, with a unique take on safety for both the operator and the people nearby. The Fotokite Phi is based on the same technology that Lupashin demo’ed on the TED stage in 2014, and that is also currently being used by major news outlets, such as the BBC, for their broadcast coverage and special programming.

Key benefits include:

Instant launch, intuitive gesture control

Fotokite is the only drone on the market that doesn’t rely on remote piloting or GPS, making for a simpler, more intuitive, user experience. To launch the Fotokite Phi, the user simply points it in the direction they want it to go and gives the device a quick shake. The onboard GoPro is powered by the Phi and automatically turns on when flying. The Fotokite’s core algorithms – developed by Lupashin while he worked on his PhD at the Flying Machine Arena at ETH Zurich, Switzerland – are protected by a patent application and enable the device to fly itself, controlled by simple gestures, on the end of the tether, with no need for a remote control or GPS.

Foldable and portable

The Fotokite Phi easily fits into a backpack or suitcase. It weighs 12 ounces, including the GoPro 3/3+/4 camera and battery, and is the lightest GoPro-carrying quadcopter on the market. The Fotokite Phi folds into a compact carrying case (about the size of a two liter soda bottle) and can easily fit in a backpack or suitcase for people traveling with it. The Fotokite Phi comes with a 26 foot leash included and a removable battery that charges directly through a USB port.

Safer for users and the people around them

If the Fotokite Phi detaches from the tether, the device is programmed to detect a lack of tension and float slowly to the ground, instead of flying away. In addition, the Fotokite’s soft propellers are safe to the touch.

Fotokite Phi folded, half in its tube

Accountability

The tether makes it clear to bystanders who’s controlling the device, allowing for accountable aerial photography. To this end, Fotokite has secured special exemptions in Switzerland and France to be flown near crowds. Fotokite is currently working towards acquiring the same permission from the FAA in the US.

Fotokite at a museum

Flight Unit

Propellers : Soft Plastic 6,5 inch Fotokite Prop

Weight : 300g (excluding GoPro Camera), 350g (including GoPro camera)

Battery : Li Po Battery (1000 Ah, 11.1Wh), 3 cells

Flight time : We are aiming for 15 minutes

Camera : Go Pro 3 / 3+ / 4

Charger : USB 3C Charging cable

Dimensions : 90mm height, 350mm diameter, 170mm rotor diameter

CPU : ARM Cortex Processor

Sensors : IMU, no GPS

Motors : 1400 Kv Brushless

Smart-Leash

8m cord, self retracting

Dimensions : 40mm height, 90mm diameter

Sensors : IMU

Case

Dimensions : 90mm x 300mm

Weight : 150g

T=0 hours. AtlantikSolar team hand launches the AS-2 at 09:32 on July 14th, hoping to set a new world record.

Two weeks after demonstrating AtlantikSolar’s first 24-hour flight, the fixed-wing team of ETH Zurich’s Autonomous Systems Lab has reached another milestone: 81.5 hours and 2316 km of continuous flight for its 6.8kg AtlantikSolar 2 Unmanned Aerial Vehicle (AS-2). This breaks the flight endurance world record in its class.

The AS-2’s fifth test flight:

• sets a new world record for the longest ever demonstrated continuous flight of all aircrafts below 50kg total mass, and is also the longest-ever continuous flight of a low-altitude long-endurance (LALE) aircraft (the previous record being a 48-hour flight by the 13kg SoLong UAV ).
• is the second-longest flight ever demonstrated by an Unmanned Aerial Vehicle (behind Airbus Space’s 53kg Zephyr 7)
• is the third-longest flight ever demonstrated by a solar airplane (behind Airbus Space’s 53kg Zephyr 7 and the 2300kg Solar Impulse 2)
• is the fifth-longest flight ever demonstrated by any aircraft (both manned and unmanned).

In addition, the flight is a first important milestone to verify the UAV’s ability to stay airborne for multiple days while providing telecommunication services in large-scale disaster-scenarios, or live-imagery during industrial sensing and inspection missions.

T=2 hours, shortly after launch. Weather conditions: occasional clouds, and strong winds up to 40km/h.

Flight Summary

The flight was performed at the Rafz, Switzerland, RC-model club airfield from July 14^th-17^th, of which the first three days provided sunny conditions. Take-off was performed via hand-launch at 09:32 on July 14^th, and after 2316km and 81.5 hours – 4 days and 3 nights – of flight, the aircraft landed safely and with fully charged batteries at 18:56 on July 17^th. The fully charged batteries would in theory have enabled to continue the flight through the night again. With the exception of take off, the aircraft was in fully-autonomous operation 98% of the time, and less than 2% in autopilot-assisted mode via its Pixhawk autopilot.

T=8 hours. Monitoring the aircraft and its energy generation and storage system. The batteries are fully charged.

The long-endurance flight provided helpful insights on the flight performance: The average level-flight power consumption in calm conditions (e.g. during night) was shown to be between 35-46W. Maximum power input throuh the 88 SunPower E60 cells during the day was around 260W. With this performance data, the aircraft managed to fully charged its batteries (100% SoC) at around 13:05 local time, before the time of maximum solar radiation (solar noon, occurring around 13:30). After flying through each of the three nights, the aircraft on average reached a minimum state of charge of 35% at around 07:45 local time, showing sufficient energetic safety margins for worse environmental conditions (such as longer nights, cloud cover or winds).

The flight also subjected the aircraft to a wide range of environmental conditions. Among them were thermal updrafts during the first evening/night (causing a remaining state of charge of 40% ), and downdrafts during the second night (remaining state of charge 32%). The last hours of the flight were marked by upcoming thunderstorm clouds and the strongest winds – up to 60 km/h – the aircraft was ever subjected to. Although the ground station was partially damaged by the winds, the airplane could be landed safely in autopilot assisted mode once the winds had calmed down.

T=41 hours. Drawing circles in the night sky using the onboard position indicator lights.

T=81 hours. Thunderstorm clouds and winds up to 60 km/h make landing the AS-2 a challenge.

T= 81.5 hours. Landing.

T=81.5 hours. A happy AtlantikSolar team after a record flight.

Future work

Having demonstrated the multi-day endurance capability of the bare UAV platform, the AtlantikSolar UAV project will now focus on extended endurance flights with payloads including optical and infrared cameras, and atmospheric sensors. These payloads will also be carried during a long-endurance and long-distance mission of more than 12 hours and 400km that is planned for later this year in the Brazilian rain forest.

Further information

Detailed design and technical information on the UAV platform can be found in “Oettershagen P, Melzer A, Mantel T, Rudin K, Lotz R, Siebenmann D, Leutenegger S, Alexis K, Siegwart R (2015), A Solar-Powered Hand-Launchable UAV for Low-Altitude Multi-Day Continuous Flight. In: IEEE International Conference on Robotics and Automation (ICRA)”

Acknowledgements

This research was funded through ETH Zurich’s internal resources, private supporters, and the European Union FP7 Search-And-Rescue research projects ICARUS and SHERPA . In addition, multiple project partners and collaborators have contributed towards making this important milestone possible, and we’d like to thank all of them for their various and ongoing support. Finally, we are grateful towards the Rafz model aeroplane club for providing the airfield and the Aero Club Asas da Planície (Portugal) for providing the backup airfield!

Pilots: Rainer Lotz, Adrian Eggenberger, Philipp Oettershagen, Bartosz Wawrzacz. Development and Operations Team (Autonomous Systems Lab): Philipp Oettershagen, Rainer Lotz, Amir Melzer, Thomas Mantel, Bartosz Wawrzacz, Konrad Rudin, Thomas Stastny, Raphael Schranz, Jan Steger, Lukas Wirth, Dieter Siebenmann, Dr. Stefan Leutenegger, Dr. Kostas Alexis, Prof. Dr. Roland Siegwart.

The flight was performed at the Rafz RC-model club airfield in excellent sun conditions. After take-off at 11:14, with batteries charged to 57%, the aircraft was quickly setup to follow an efficient and fully-autonomous loitering path, which allowed a completed battery-charge by 14:08 o’clock.

The midday and afternoon were characterized by strong thermal up- and downdrafts, but enough power was generated by the solar panels to keep the batteries full. Their discharge started only when the sun slowly went down at around 19:30.

The night flight provided calm conditions, with the autopilot keeping the aircraft stable despite horizontal winds of up to 5m/s, and the safety pilots keeping a good eye on the aircraft using its position indicator lights. Flying at an average airspeed of 8.4m/s (the point of minimum sink rate) and an average power consumption of 43W during the night, the aircraft received first sun at around 5:50 o’clock, and maintained a minimum charge of around 35% until the solar modules regenerated enough power to stay airborne.

After 24 hours of continuous flight, the aircraft had recharged its batteries to 84%, a significantly higher state-of-charge than the day before. The batteries were in fact fully charged by 12:43 o’clock – one hour and twenty-five minutes earlier than the day before.

AtlantikSolar landed safely at 15:35, thereby setting a new Swiss endurance record for unmanned solar-powered flight, and improving upon the previous internal record (ASL’s Sky Sailor) by a over an hour.

The project’s next goal is to extend the flight duration to more than 80 hours (3 days), in order to beat the old endurance record for solar-powered UAVs below 20kg (48h flight by the 13kg SoLong UAV in 2005) by more than a day. If it is able to achieve an 80-hour flight endurance, the 7kg AtlantikSolar would be the third-longest flying aircraft in the world, only behind Airbus Space’s 53kg Zephyr and the 2300kg Solar Impulse 2.

We’d like to thank everybody who made this flight possible — including all project partners and collaborators, the Rafz Model airfield club, and our safety pilots — for working so hard and making this big step in the project possible.

The AtlantikSolar project was developed at the Autonomous Systems Lab at ETH Zurich. 

The adaptive solar façade is assembled on the south side of the House of Natural Resources. (Photo: Marco Carocari)

By Arno Schlüter
Today, building envelopes tend to be static and unable to adapt to changing conditions. Now, for the first time, an adaptable façade has been used for the newly inaugurated House of Natural Resources (HoNR) that produces electricity and regulates light and heat generation.

The envelope of a building is of great importance to its energy balance, and insulation and air-tightness have improved significantly in recent years. But there is also significant untapped potential when it comes to contributing to the transition of our energy system towards renewable energy sources: the building envelope of a building, particularly the façade, can be designed to recover heat and generate electricity.

From rigid to dynamic structures

As the boundary between interior and exterior spaces, the façade influences the air, light and heat balance of a building significantly – and thus has a direct impact on the comfort of users. Both spaces are stochastic by nature: they change constantly and conditions are at best only vaguely predictable. And yet the envelope of a building is usually static, focusing on only one or just a few different situations. Today’s building envelope is rarely adaptable to changes in weather or the use of a room. This considerable potential for energy conservation and generation, as well as improved comfort, remains unused.

At the Chair of Architecture and Building Systems, we are researching approaches to make the building envelope more dynamic, efficient and adaptive. One example is the adaptive solar façade, which consists of individual modules mounted on a cable network on the façade. By adjusting the amount of solar radiation through the window, they can control the light and heat of the internal space and at the same time produce electricity through highly efficient thin-film solar cell modules. The adaptive solar façade is also very lightweight, so in contrast to traditional photovoltaic panels it can be mounted almost anywhere, including on existing buildings.

Soft robotics for adaptability

The soft actuator can move the module. (Photo: Professorship of Architecture and Building Systems)

The modules are moveable thanks to a new device, the soft robotic actuator, which originates from a new and promising field of robotics, soft robotics. It is made of flexible materials that take multiple forms when the pressure in the special chambers change. Such actuators are normally used mainly for prosthetic and biomimetic robots; we are now exploring and developing them for future energy and climate systems in buildings.

Our soft actuator is manufactured with a specially developed hollow casting process and the chamber is then filled with air. Valves control the air flow by pumping or releasing air to deform the actuator and thus move the solar element selectively. With soft actuators, we can control each adaptive solar façade module individually and rotate it on two axes, either on its own or in groups. This enables the modules to track the sun’s movement and generate power, use or limit solar power, create privacy or open up the view. An intelligent and adaptive regulator allows the façade to adapt to changing weather conditions and the habits and wishes of the user.

Prototype at the House of Natural Resources

A view of the adaptive solar façade from inside the building. (Photo: Marco Carocari)

Without soft actuators, such functionality would be possible only through a complex combination of several mechanical parts. These would be less durable and more expensive – making it unlikely that they would achieve widespread use in façades. In contrast, our actuator costs only a few francs when produced industrially. The soft actuator has been proven to be robust in cyclic tests in the laboratory; now it has to prove that it is just as effective in the harsh conditions of a building façade. To test this, along with various other factors, we have assembled a prototype façade of 50 modules on the south side of the House of Natural Resources (HoNR).

The module uses highly efficient copper indium gallium selenide (CIGS) thin-film solar cells for top performance: the solar cells are developed by the EMPA spin-off Flisom [1], our industrial partner in the project. First life-cycle calculations have shown that it would take only 18 months for the adaptive solar façade to offset the CO2 emitted in the module’s manufacture.

As part of the EU Climate-KIC’s Building Technology Accelerator flagship project [2], we are currently investigating how and in what form the adaptive solar façade, and thus the soft actuator, can be developed into a marketable product. If this is successful, our adaptive façade could contribute to the efficient generation of building energy and thus to energy transition.

Further information

House of Natural Resources HoNR

Website of the Chair of Architecture and Building Systems.

References:

[1] EMPA spin-off Flisom

[2] EU Climate-KIC BTA flagship project

Tailsitter in the Flying Machine Arena. Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

In August 2014 Google [x] announced that they had been secretly developing a drone delivery program to rival Amazon’s Prime Air. Called Project Wing, the system was based on a mechanically simple “tailsitter” design – a hybrid vehicle that takes off vertically like a multirotor but is also able to fly horizontally like a fixed-wing airplane. Following field tests, however, Google scrapped the design, saying that it was difficult to control and didn’t perform well in high winds. Since then, researchers at ETH Zurich have developed a new algorithm for robustly controlling a tailsitter flying machine in hover position. Using the algorithm, the tailsitter is able to recover from any orientation, including upside down. ETH has not yet demonstrated its algorithm in real-world conditions (e.g., high winds, GPS localization, different payload distributions). However, given the robustness of the solution shown in the video, perhaps Google should not dismiss the tailsitter design too quickly for its next design iteration.  

– Robohub Editors

A tailsitter provides hover capability by pointing the nose and thrust direction upwards. For fast forward flight, the vehicle tilts to a near-horizontal orientation, resulting in efficient lift production due to the conventional wing design. Compared to other fixed-wing, hover-capable aircraft such as tiltrotors and tiltwings, the major advantage of a tailsitter is its mechanical simplicity: no mechanism for changing the direction of the propulsion system has to be added, saving weight and increasing reliability.

The algorithm demonstrated in the video is based on Optimal Control. Optimal trajectories for a set of initial orientations are precomputed and the corresponding initial desired body rates are stored in a small lookup table (500 entries). An outer control loop running at 50 Hz reads the desired body rates for the current orientation from the lookup table, and feeds them to an inner control loop. The inner control loop runs at 1000 Hz and tracks the desired body rates with the two propellers and the two flaps using feedback from a rate gyroscope. The resulting real-time computational complexity is extremely low.

Tailsitter’s propellers and motors. Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

The propellers are driven by brushless Hacker A05-13S motors that are attached to the wings by 3D-printed mountings. While the vehicle is hovering, it is crucial that a large part of the flaps are within the propeller-induced airstream, in order to keep the flaps effective and the system highly maneuverable. The motors are controlled by ZTW Spider 12A ESCs, which run custom SimonK firmware that enables a fast response to thrust set point changes. Since the custom SimonK firmware is tuned for the fastest possible response, the motor controllers get quite hot and are therefore placed in the propeller airstream for cooling.

Tailsitter’s underbelly. Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

Two radios are attached on the bottom side of the vehicle; a WiFly module for high-bandwidth telemetry, and a low-latency, frequency-hopping 2.4 GHz radio link that receives the control commands from the ground station. The total system latency including the motion capture system and the radio link is around 35 milliseconds.

Tailsitter’s flaps. Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

The flaps are actuated by MKS DS65K servos providing a fast response on flap angle changes. The flaps of the original frame are designed for fixed-wing forward flight and do not provide enough control authority for the hover flight regime. Therefore their area is enlarged by carbon fibre sheets. This increases the effectiveness of the flaps by a factor of four. The maximum flap deviation is 30 degrees.

Tailsitter’s flight management unit (FMU). Source: Robin Ritz, Institute for Dynamic Systems and Control, ETH Zurich.

A Pixhawk PX4 Flight Management Unit (FMU) runs the onboard control loop that tracks the desired body rates using a rate gyroscope which is also provided by the FMU. Safety routines that switch off the actuators if the vehicle does not receive control commands anymore or if the battery voltage is too low are also implemented on the FMU.

The algorithm is presented in research paper “A Global Strategy for Tailsitter Hover Control”, submitted to International Symposium on Robotics Research (ISRR), 2015.

Researchers
Robin Ritz and Raffaello D’Andrea
Institute for Dynamic Systems and Control, ETH Zurich
Flying Machine Arena

Technical details
Frame: Robbe Mini Wing RC styrofoam airframe
Electronics: Pixhawk PX4 Flight Management Unit
Battery: Thunder Power RC G6 Pro Lite 25C LiPo 350mAh 2S
Motors: Hacker A05-13S
Motor controllers: ZTW Spider 12A ESCs with SimonK firmware
Propellers: 5×3 GWS EP-5030
Flap servos: MKS DS65K
Infrastructure: Flying Machine Arena

• Multiple tethered quadrotors whip around a pole together at high speeds 
• Quadrocopter failsafe algorithm: Recovery after propeller loss
• Three new quadrotor videos demonstrate agile control and the power of machine learning
• Video: Quadrocopter learns from its mistakes, perfects slalom air racing

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

By: Vanessa Bleich
Next year’s Cybathlon will host people with physical disabilities equipped with advanced assistive devices including robotic technologies. The goal of this unique competition is to remove barriers between people with physical disabilities, researchers and the general public and to promote the development of assistive technologies that are useful for daily life. We talked to Robert Riener, the Cybathlon’s main organizer and Professor of Sensory-Motor Systems at ETH.

Robert Riener is the initiator and organizer of the Cybathlon. (Photo: ETH Zurich / Giulia Marthaler)

You are the initiator and main organizer of the Cybathlon. How did the idea for this event come about?
As a researcher, I’m always on the lookout for opportunities to present my research to the general public. A few years ago, I read an article in the newspaper about a man who climbed the stairs at the Willis Tower in Chicago using a motorised prosthetic leg. It inspired me to think about a similar event that could be held here in Switzerland – an event that would extend beyond a single race to include many other disciplines. Through talks with colleagues and employees, I gradually developed the idea further. I also thought increasingly about what exactly we wanted to communicate and achieve with this event.

What do you hope to achieve through the Cybathlon?
Our original idea, which was to present our research findings to a wider public, of course remains a goal that we continue to pursue. But we would also like to raise people’s awareness of the needs of people with physical disabilities and the obstacles they face in everyday life. Unfortunately, many people without disabilities know very little about the challenges faced today by people with physical disabilities. Alongside technical assistance, for example, accessibility is also extremely important. We believe this knowledge, in turn, can break down more barriers.

Besides overcoming reservations about the field, we want to motivate developers to create technologies that provide real support to people in daily life. That is why the races feature everyday obstacles, such as stairs, ramps and doors. We hope Cybathlon’s competitive nature will boost the development of powered assistive technology in the long term. It’s already having a positive impact: new student groups have been formed and research projects have emerged. Both students and researchers are working at full speed on their prototypes.

What are the main difficulties when developing electrically powered devices?
The weight-performance relationship is one of the greatest challenges. For example, if you want to build a wheelchair that climbs stairs, it must be wider for stability reasons. When combined with the additional mechanics and propulsion system, it’s automatically heavier. The same goes for the development of the exoskeleton. The integrated batteries must be very efficient to allow the wearer to move freely and independently throughout the day, but these batteries weigh a lot.

Cybathlon

The Cybathlon will take place on 8 October 2016 at the Swiss Arena in Kloten. People with varying degrees of disability, aided by cutting-edge assistive technology, will participate in the unique competition. A team is comprised by a technology provider and at least one pilot who directs the technological device. As a result, two medals await each winning team at the Cybathlon: one for the parathletes and another for the provider. The technological device that is deployed can either be a product that is already available on the market or a prototype from a research lab.

The competition features six different disciplines:

• Powered leg prosthesis race
• Powered arm prosthesis skills course
• Powered exoskeleton obstacle course
• Powered wheelchair race
• Functional electrical stimulation bike race
• Brain-computer interface virtual race

Robert Riener, head of ETH Zurich’s Sensory-Motor Systems Lab, is the initiator and main organizer of the Cybathlon.

Are there other challenges besides the power supply?
While the performance data for the powered leg prosthesis is already very good, the control is more problematic. The wearer’s intended movements must be correctly conveyed to the leg prosthesis. This means that the prosthesis should automatically detect what the person wants to do, be it standing up, sitting down or climbing stairs. This is less of a problem when it comes to conventional, passive prostheses because the wearer intuitively propels them by moving or swaying.

What is the current state of research in the area of powered assistive technology?
The technology is already quite advanced today in some areas. For example, it is now possible to run quicker with certain leg prostheses than a human with natural legs could. But such prostheses are only helpful for specific movements. You may be able to walk quickly, but not be able to sit down, walk up stairs, or drive a car. Most of the available aids have significant deficits with regards to everyday functions and potential users have therefore failed to embrace them. This is where the idea behind the Cybathlon comes in: systems need to be developed that provide help to people with disabilities where they need it the most – in daily life.

How does the Cybathlon differ from other competitions such as the Paralympics?
People with disabilities can participate and compete in both events. The Paralympics, however, is primarily a sporting competition. Technology remains in the background and the use of motorised wheelchairs or powered prostheses is not permitted. As a result, many people are unable to compete. At the Cybathlon, on the other hand, «pilots» with greater restrictions who primarily direct the technical aids – are also eligible to participate. Although people are at the centre of our event, technology also plays a relatively large role.

The Paralympics are focused on sporting disciplines. In addition to races honouring the athlete who reaches the finish line first, the Cybathlon competition also includes skills and obstacle courses featuring everyday tasks and barriers. It’s not only the time that counts; pilots also receives points for their skills. Just like in classic sporting events, competition drives both the pilots and the technology developers at the Cybathlon. They inspire each other to deliver their best performance.

What has the response been to the planned event up until now?
There’s been a great deal of interest in the event. We have received very positive feedback from the scientific community, the media and well-known Swiss organisations for the disabled. The disability associations share our view that the Cybathlon could contribute to the development of current devices. Some critics, however, argue that these sorts of efforts should be focused exclusively on making buildings and the environment barrier-free. But the world does have barriers and you can’t just make them disappear – there are hills, forest paths and so forth. Researchers are developing technologies so they no longer pose obstacles in the future.

• Novel robots for gait and arm rehabilitation: Interview with Robert Riener
• Introducing the Cybathlon
• Registration now open for Cybathlon 2016

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The testbed allows the quadrocopter’s high speed flight behavior to be characterized in order to determine drag characteristics, propeller efficiency, and the physical limits of the machine. It is also being used to safely develop high-speed maneuvers such as emergency braking.

Note that it is possible to remove the central pole by balancing the forces acting on the strings; this could be then used in performance settings, possibly enhanced by light and sound effects.

This research was conducted at the Flying Machine Arena at ETH Zurich.

Reference:

Maximilian Schulz, Federico Augugliaro, Robin Ritz, Raffaello D’Andrea , “High-speed, Steady Flight with a Quadrocopter in a Confined Environment Using a Tether “, IROS 2015, submitted.

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The Kuka lightweight robot with a mounted stone tool replica in an ETH Zurich lab. (Photo: Fabio Bergamin / ETH Zürich)

By Samuel Schlaefli

With the help of robots, archaeologists may soon be able to compare their findings with data from thousands of experimental reference samples, enabling them to determine tool use in the Stone Age. ETH scientists have developed a robotic system and presented it at the industry fair in Hanover.

Kuka-Roboter

Radu Iovita is an archaeologist. He remembers well his student days, when he spent hours scraping away at animal skins with replicas of stone tools found at archaeological sites – all for a bit of pocket money. Through analysis of wear traces under a microscope, archaeologists seek to determine how the tools were used thousands of years ago. This method, known as ‘use-wear analysis’, is a standard approach in modern experimental archaeology today.

“Manual use-wear analysis is incredibly time consuming, and we are unable to control factors such as the force with which a tool is used or its position,” says Iovita. He has spent the past few years looking for opportunities to conduct controlled experiments and experienced initial success with a system using air guns to run a controlled test on the impact-related fractures of Stone Age spearheads.

Archaeologists and robotics team up

But the archaeologist was looking for ways to examine all tools and their application systematically – as well as being as automated as possible. Iovita, now a researcher at the Monrepos Research Centre (RGZM-Leibniz Research Institute for Archaeology) in Neuwied, Germany, remembered Jonas Buchli, a professor at the Institute for Robotics and Intelligent Systems at ETH Zurich, whom he had met 10 years before at a summer school on complex systems. The ETH professor was impressed from the outset with Iovita’s idea to automate archaeological research through the use of robots to standardise the measurements.

Buchli’s then graduate student Johannes Pfleging equipped replicas of stone tools with sensors. Just as Iovita did during his studies, Pfleging scraped at the animal skins, but with a difference: his movements and the force used were recorded by a computer. In doing so, he found evidence that the sensors provided important data that could be used to reproduce and compare the experiments at a later date. But use-wear analysis still remained time-consuming.

By a stroke of luck, the Kuka robotics company had just announced an Innovation Award that made lightweight robots with force control available for use in innovative research projects. These robots are very light in comparison to their load weight and can adapt the forces used to the determined resistance within milliseconds.

A robotic arm for fully automated analysis

One such Kuka robot has been in Buchli’s laboratory since last December. Pfleging, now a doctoral student, has fixed the grey robotic arm with its seven degrees of freedom on to a wooden table. At the end of the arm is a plastic adapter with a piece of wood in which he glued a replica of a stone tool. As soon as Pfleging starts a computer program he wrote himself, the arm begins to use the stone to scrape a piece of leather fastened to the table. After a few rounds, it bends down and guides the tool under a microscope next to it on the table. An image of the stone, magnified 80 times, appears on Pfleging’s computer, revealing fine abrasions.

“With such a system, we can not only automate the painstaking production of wear traces, but also the analysis of the replica,” explains Buchli. Several robots could work leather, stone or wood with replicas of tools 24 hours a day and run the tool after every 50th movement under the microscope to take images of the surface. Thus, a combination of the data and force of the robotic arm would allow a precise reconstruction of how certain abrasions had been achieved. “Through such analytical data, we could one day create massive databases with all the characteristics of archaeologically relevant information on materials and their wear patterns,” explains Buchli.

Deeper insight into ancient civilisations

Wider comparisons such as these have the potential to accelerate the production of knowledge in archaeology and paleoanthropology. For each archaeologically-recovered stone artifact, the researchers could compare a microscopic image with thousands of records from use-wear experiments from around the world, allowing them to make inferences about how the tool was formerly used.

“In archaeology until now, we have been primarily occupied with the morphology of objects,” says Iovita. “However, it is only when we know what the tools were used for that we can make inferences about culture.” It is also generally assumed today that the prehistoric evolutionary development of humankind can be inferred from how tools were used and the cognitive skills needed to use them. In particular, scientists are still groping in the dark when it comes to the use of tools from the period between 3 million and 50,000 years before present.

Paradigm shift underway

Currently, Iovita is experiencing some opposition from within his own profession. Some believe that manual experiments are closer to the past reality; others find that use-wear analysis in general does not advance archaeological theory. Iovita thinks this is mainly due to the fact that most archaeologists have a humanities background and are not familiar with the world of engineers.

“However, a generational and paradigm shift is currently underway,” he believes. “The interest in automated analysis is growing and more and more archaeologists have access to the relevant technology.”

Iovita has put in an application for the establishment of a trace laboratory at the research centre in Neuwied, where the first use-wear analysis with robots will be conducted in the next two to three years. Buchli and Pfleging have now presented their robotic system to experts as part of the Kuka Innovation Award at the industry fair in Hanover. Next, they will develop a prototype in their laboratory that is better suited to archaeological use and cheaper than conventional lightweight robots with force control.

“In 10 years’ time, robotic analysis will be the standard in archaeology,” predicts Buchli. “For the first time, research results would be truly comparable because the methodology behind it is standardised and the devices properly calibrated.”

This article first appeared on ETHZ News. 

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Matthias Kohler, Balz Halter and Jonas Buchli (Photo: Nicole Bachmann).

By Felix Würsten and Corinne Hodel (Interview).

Digital technologies have already turned many areas of the economy inside out. In this interview with Swiss NCCR Digital Fabrication researchers Matthias Kohler, Balz Halter and Jonas Buchli, we hear how construction is the next sector set to undergo a change, enabling more efficient processes, new materials and more varied houses.

The website of the new National Centre of Competence in Research (NCCR) Digital Fabrication states that: “Digital fabrication promises to revolutionise architecture.” Does architecture need a revolution?

Matthias Kohler: That is less of an objective than an observation: the construction process is still highly conventional. Other sectors of the economy have been profoundly transformed by digital technologies. This raises the question of whether architecture and its downstream construction processes are also set for a change. The NCCR Digital Fabrication addresses this question: what is the added value if components are fully assembled by machines? What conditions need to be fulfilled so that people can work together with robots on building sites? And what effect will this have on drafting, planning and the construction culture?

Yet it must be noted that houses were built by robots in Japan some time ago. Are you reinventing the wheel?

Kohler: It’s true that some initial steps towards automation on building sites were already taken in Japan in the 1990s. There was a boom, but it collapsed suddenly for economic reasons. The idea at the time was to bring serial mass production from factories to building sites. It worked, but this technocratic approach resulted in limits on the architecture and bland buildings. In today’s construction culture, a fitting, “tailor-made” solution for each situation is the objective. The quality of our living environments relies on this. When we take our robots to the building site today, our motivation is quite a different one: we are trying to establish how the processes can be rationalised, but continue to allow tailor-made production at the same time. That’s the actual novelty: every machine-made component can look different, even the individual production steps can be customised to a certain degree. That’s what we’re doing with our robots, for instance: depending on the task, the same robot uses different tools to assemble, process or shape something. This approach results in rational production already for relatively small lot sizes.

Is there actually any demand from developers for individualisation?

Balz Halter: Developers certainly want a more individualised appearance for their buildings. This is also having an impact on architecture: new shapes and materials are being sought. In the construction industry, we abandoned the mass production mentioned earlier because we noticed that this approach keeps resulting in the same buildings. The construction industry is indeed aiming for individualisation, because ultimately it also offers a way to stand out amongst competitors.

What is your motivation as a robotics expert to look at construction processes?

Jonas Buchli: Many sectors of the economy have been turned inside out by digitalisation. This has affected, above all, areas where either data play a key role or where problems can be easily structured. In robotics, however, we now need to take the next step, which is to say that these technologies need to be brought to areas that are less structured, where more flexibility is needed and the machines need to react in a more timely fashion. The construction industry is an interesting starting point for this. A building site is certainly less well-structured than a factory, but still not quite as open as the world of service robots, for instance, which perform activities independently in the household. The potential in the construction industry is huge. But we will only be able to tap it if we solve complex robotics problems. That’s an interesting challenge for me as a researcher.

What has it been like to work with architects?

Buchli: When working with architects, the challenges and possibilities are entirely different than when “only” collaborating with engineers. I am learning an awful lot and am facing an entirely new perspective. What has surprised me is how pragmatic their approach is to using technologies and how target-driven their work is.

What has been implemented to date?

Kohler: We’re currently still at an early stage of research, although some companies have already taken specific steps towards digital fabrication. It will take a great deal of time until the new production processes have become ingrained and until the experiences have been integrated along the entire production chain. In tile and timber construction, we have seen that implementation will take at least six to ten years. When applied across the entire construction industry, these changes will take several decades. What excites me is the question of what we will gain from these technologies in terms of quality in architecture and in the construction processes, and what benefits they will bring for Switzerland.

Halter: In practice, digital fabrication is certainly a known concept today. In timber construction, in particular, a lot is already being done. The fact that these technologies are not yet broadly applied is not so much a matter of possibilities: the problem is that we can only produce digitally if the data are available in a corresponding form. In this area, our industry is simply underdeveloped. There is no integral process from drafting to production through to operation. If we were to start by handling the data correctly during the planning process, implementation would be far easier. We actually have all tools at our disposal already. But our industry is still not able to use these tools.

Why is that?

Halter: First, this has to do with the fact that we still think in a very subsection-specific way. In other words, we don’t understand the building as an overall system. Second, we keep interrupting the planning process because we transfer data from one place to another. And third, the construction industry is organised in a highly commercial and work-sharing manner. The production of a car is a unified procedure; that’s not the case for buildings. But construction is not more complex than car manufacture – we are simply aligned in such a way that it becomes more complicated. That’s why processes are still very antiquated on building sites. But that is also an opportunity, of course, in particular for the design process. What’s important to us is that digital fabrication results in quality improvements and ultimately also generates commercial benefits.

Buchli: The entire development will likely happen in a similar way as in computer technology. When we had the first computers on our desks, processes were hardly productive yet. But there were early adopters, who were thinking ahead. Only now, after many years, are computers really productive for normal users. We will undergo the same development in the construction industry. However, the problem is far more complex here, which is why the time frames will be longer. We won’t be looking back in two or three years saying whether it has worked or not.

Where do you expect to see the first steps?

Buchli: What will likely become established in the near future are transport applications as well as certain precision applications. Today, we can produce structures at a level of precision that a human cannot achieve, at least not within the same period of time and working under the same conditions that robots do. However, if we want to bring these things to building sites, we need to increasingly include information from the building in the planning process. This was a directed process in the past: first plan, then execute. What we need now is to close the circle.

Kohler: The crucial question is, of course, how this vision is implemented. Up to this point, architecture has mainly focused on the mental work. The idea was to develop a sophisticated planning software that integrates everything. This still largely works in planning today. However, where the matter becomes physical, the processes mostly remain conventional. We are now changing our perspective and looking for solutions that can be integrated retroactively, in other words from execution to drafting. I’m convinced that this approach will make it far easier for the construction industry to initiate a sustainable transformation from within.

Do you share this view?

Halter: A lot speaks for this approach. The development is driven strongly by architects who focus on the end product and who work with components and materials that can only be implemented in a digital process. For instance, there are facades that can only be planned and produced on a data-driven basis. It will also be exciting to see what influence 3D printers will have. This is precisely the point: we look at what options we have in production and go back to the draft with this as our vantage point until both ends meet.

Kohler: 3D printing is a very interesting catchword: 3D printers cannot simply be applied to architecture, although it is often presented this way. In principle, additive processes are interesting for us, of course. This has to do with the fact that good architecture is based on the artistic assembling of elements to create rooms that are larger than the machines that build them. This is where 3D printing comes in: how do we find the structuring strategies in architecture that are based on digital technologies, but nevertheless take into account the requirements and economy of architecture? For instance, it makes little sense to print an entire building. Due to the resolution at which the printer works, the construction process takes a very long time and the material is also very expensive. However, if larger construction elements are used, a construction-aligned resolution can be achieved.

Can you elaborate a little on this?

Kohler: I am speaking about new digital material systems, for instance: suddenly it’s possible to handle a building material in an entirely different way thanks to digital technologies. It is very possible that this will result in developmental leaps. We also need to consider the ecological aspects: today, concrete walls are designed in such a way that they withstand the worst load scenario. These walls are built with a straight mould system. This results in about one third of the concrete not actually being needed from a statics perspective. If we use systems that don’t need moulding, there are direct consequences for our handling of material resources. If the construction culture develops in this direction, we will thereby also be able to create added value in this area with the use of digital fabrication. Our research projects allow us to generate knowledge which Swiss companies will be able to use internationally. We would be delighted if the industry were to pick up on these stimuli and if our projects were to result in interesting collaborations.

What effects do these developments have for the people involved in the actual construction process?

Halter: It’s becoming increasing difficult to find the experts required. For that reason, we need to try to support the processes on building sites in terms of information technology in such a way that the required skills are more limited. This objective is also driven by commercial considerations, because the individual worker is becoming increasingly expensive.

What do you think of the roll-out of the new MAS Digital Fabrication programme at ETH Zurich, which is starting for the first time this year?

Halter: No question: we need a programme like this. Because the development we have just been discussing can only happen if we also make changes to education. We need people who can handle these types of technologies. We are consistently initiating innovations, but are also noticing that people are out of their depth in practice, because they are faced with something that they don’t know. A planner doesn’t see why he should do something differently, because he doesn’t get paid more but he does have to take on more risk. If he has no inherent drive to try a different approach for a change, and cannot even know the opportunities, then he simply won’t do it. That’s understandable.

Matthias Kohler is Professor for Architecture and Digital Fabrication at the Architecture Department of ETH Zurich. In 2005 he established the world‘s first robot laboratory for nonstandardised fabrication processes in architecture with Fabio Gramazio and thereby opened up an entirely new field of research.

Jonas Buchli is Professor for Agile Robotics at ETH Zurich. His research focuses on modelbased approaches to controlling robotic locomotion and understanding human locomotion as well as on machine learning and on dynamic service and field robots.

Balz Halter is the owner and chairman of the board of directors of Halter Unternehmungen, which are active in the development, construction and operation of real estate property. He is an ETH graduate civil engineer and lawyer.

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Photo credit: Gramazio Kohler Research, ETH Zurich.

In September a new Master of Advanced Studies (MAS) ETH in Architecture and Digital Fabrication will be offered by the Gramazio Kohler Research chair at ETH Zurich. This one-year, full-time program focuses on digital design and full-scale fabrication using state-of-the-art robotic fabrication facilities at ETH. The MAS is embedded within the National Centre of Competence in Research (NCCR) Digital Fabrication, itself an ambitious research initiative at the intersection of architecture, engineering, robotics, material and computer sciences. Interested candidates are invited to apply until April 30, 2015.

The term “digital fabrication” refers to the seamless combination of digital planning with the physical fabrication process. The project data is sent to a machine, and directly implemented in reality. However, this exchange of information could also work in the other direction: the physical conditions could immediately influence the computer-aided designs.

For architecture, this opens up possibilities that were previously undreamt of, and which go far beyond purely design-related aspects. New construction systems, material systems, resource-saving production, efficient-yet-flexible engineering and construction processes, and a transition from mass production to customised industrial production all promise a decisive developmental step towards a sustainable building culture for the future.

Unlike objects produced by conventional computer-controlled production, architectural objects are typically larger than the actual production facility, they are always unique, and they are usually produced on site. As a result, research on this topic is confronted with completely new questions: How can the automated industrial robot in the factory hall become a reactive robot for the building site? What intelligent material systems and construction systems are suited to a robot-based additive (and thus waste-free) building technique? And what do the new planning and building processes mean for the future interaction between humans and machines?

The practicability (and thus the success) of digital construction will depend not only on research, but also, to a great extent, on experts who can ensure the transfer of knowledge into practice. This is why the NCCR Digital Fabrication, in conjunction with ETH Zurich, is launching the new Master of Advanced Studies (MAS) in Architecture and Digital Fabrication next autumn. As the education platform of the NCCR, this programme is embedded in the context of the latest research findings. In the NCCR’s unique robotic fabrication facilities, the students will also have the opportunity to research digital design and construction processes, and to implement these directly in large-scale prototypes.

More info: http://www.dfab.ch/education/mas/

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Knee orthosis as worn by first author Mike Tucker (photo: ReLab, ETHZ and Alain Herzog).

Much has been made of the numerous advances in robotic prosthetics and orthotics (P/O) over recent years, and the question of how to control these devices so that they work in accordance with the intention of the user is a continuing dilemma for roboticists. 

A team from four labs within NCCR Robotics, across ETH Zurich and EPFL (ReLab, ETH Zurich; LSRO, EPFL; SMS, ETH Zurich and CNBI, EPFL) have recently published a joint paper in the Journal of NeuroEngineering and Rehabilitation, in which 10 experts from the field review the state of the art in control approaches for active lower limb P/Os. They argue that for P/Os to be fully viable and to advance further, they must be treated as part of a framework whereby the control system becomes integrated with the user’s sensorimotor system.

Traditionally, the fields of orthotics and prosthetics have been viewed separately, with hardware and controllers developed with a specific portion of the body in mind (i.e. knee, ankle and hips). By taking a broad survey that includes research for all joints of the lower limbs across the different fields (rather than just looking at a small subset), it is hoped that future developments can blur the lines between fields and create technologies that can ultimately restore walking to those with physical or neurological impairments.

This open access review pieces together where the state of the art is now and what work still needs to be done, providing valuable background about the field.

The authors behind the paper have been working to enhance communication between research groups, and to promote a more holistic approach to P/O devices. One of the co-authors is organizing next year’s Cybathlon, where teams comprised of bionic technology developers and a pilot will compete in one of six races.The competition’s ultimate aim is to increase discussion between academia, industry and end users through friendly competition.

Working out the mechanics of walking is a major step towards creating assistive technologies.

When thinking about robots that can be used to care for the elderly, most people imagine humanoid robots that are meant to help with cooking, cleaning and socializing. But what if robots could be used to keep elderly people from needing help in the first place? Walking assistive devices could be just the tool.

A key element of life quality for the ageing population is preservation of mobility. Being able to walk unassisted is essential for independent living and a crucial driver in maintaining quality of life and self-autonomy. In elderly populations, a wide variety of medical issues lead to loss of mobility, from stroke (CVA) to poorly healed fractures and general loss of muscle mass. Loss of mobility is therefore a key driver in the commonly reported issue of loneliness in elderly people – it makes sense that if it is a struggle to leave your house, you will do so less.

The first requirement for free walking is sufficient muscle strength, not just for walking but also for the associated tasks of day to day life, such as sitting-to-standing motions (and visa-versa) and ascending and descending stairs. For various reasons, the elderly population is subject to weakening muscular power and this is a larger driver in the difficulties that this population begins to face with such tasks.

LSRO (EPFL) in association with NCCR Robotics, propose an assistive device targeted for exactly this situation. Based on an exoskeleton, it is being designed to be usable at home, without permanent human assistance. It should allow normal walking without any impediment. It should provide assistive muscular power only when needed and without any specific command action other than natural motion of the legs.

For a first prototype, the focus has been on the hip joint, a key joint for walking assistance, and an assumption has been made that ankles and knees can still perform their normal functions. “Partial devices” such as those proposed by the Swiss team may offer promising solutions to issues faced by the elderly, who may experience excessive weakness in one joint (here, the hips), by providing a lighter weight and less invasive solution to full exoskeletons. Translating these needs into engineering specifications leads to the following requirements: A single motorised degree of freedom (pivoting of the femur in the sagittal plane), preserving the full mobility of the remaining degrees-of-freedom, high power and low weight, “transparency” for normal walking, no specific control action (such as a “joystick” command) of any kind.

The exoskeleton is designed to be easy to wear, without impeding movement.

The kinematic design of our device is such that torque is intrinsically high around the horizontal position of the femur (typical for sitting-to-standing, stair climbing) and is backdrivable in standing or walking posture (high compliance, “transparence”), thus allowing effortless and swift walking motion. The transmission ratio between motor and end-effector is thus intrinsically, by design, continuously adapted at an optimal value.

Our new types of actuators have been developed so as to fit the requirements of common activities of daily life. For instance, a variable reduction using a ball-screw and bar mechanism to assist different activities such as standing up from a sitting position or standard walking has been evaluated. A high torque is required during the sit-to-stand transitions when the flexion angle of the hip is around 70° from vertical. During walking, less torque is required but higher dynamics is needed. A smaller reduction ratio is therefore better adapted when the flexion angle is less important (i.e. in the walking range of motion). In order to create this specific transmission a ball-screw with an excavator-like mechanism was implemented.

The influence on gait of this kind of robotic hip orthoses are now being assembled and tested in a collaboration between LSRO at EPFL, SMS Lab at ETH Zurich and several clinical centres of elderly care. As the users are able to move on their own, it is very important that the exoskeletons do not. Indeed the added limitations imposed by a sub-optimally designed device may overshadow the benefits that it is intended to provide. The influence of different design parameters such as kinematic configuration, overall mass or user interface are therefore evaluated in collaboration with the Sensory-Motor Systems Lab (SMS) at ETH Zurich.

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Dear Robohub- and Robots Podcast-Team,

We are happy to share with you our latest Robotics Christmas video!

Have a holiday robot video of your own that you’d like to share? Send your submissions to info [at] robohub.org!

ETH and the university of Zürich receive a 120 million dollar donation from ETH alumnus Hansjörg Wyss. (All photos: ETH Zurich)

ETH Zurich and the University of Zurich are founding a new translational research centre at the interface of medicine, science and engineering: the Wyss Translational Center Zurich. A USD 120 million donation from Dr. h.c. mult. Hansjörg Wyss to the two Zurich universities is making this possible. Through an interdisciplinary approach, the new centre aims to accelerate the development and application of innovative medical therapies and groundbreaking robotic systems.

ETH Zurich and the University of Zurich (UZH) are taking their long-standing partnership to a new level with a new translational research centre. The two universities are founding the Wyss Translational Center Zurich (WTZ) with funds donated by Hansjörg Wyss to the ETH Zurich Foundation. The core idea and motivation behind the initiative is to ensure that knowledge from basic and pre-clinical research can be applied in practice more quickly; in other words, an efficient translation into new medical therapies and innovative products.

The WTZ will initially include two technology platforms – one for regenerative medicine and the other for robotics. The centre will bridge disciplinary and institutional barriers and unite researchers across various disciplines, ranging from technology and medicine through to materials science, stem cell research and robotics. “Basic research in Switzerland is among the best in the world. However, it often takes a long time until the findings can be used to benefit patients. I want to help speed up this transfer with new models of interdisciplinary collaboration”, states Wyss, founder of the medical technology company Synthes Global and chairman of the Wyss Foundation.

The USD 120 million donation is a basic endowment to establish and operate the WTZ for the first seven years. ETH Zurich and UZH will provide personnel and infrastructure in the new centre. On the basis of the two translational technology platforms – regenerative medicine and robotics – the WTZ will commence operations in 2015 with a starting portfolio of four translational projects: Zurich Life Matrix, Zurich Heart/Ventricular Assist Devices, Zurich Liver and Zurich Eye. More groundbreaking transfer projects will be added over time. “The generous donation from ETH alumni Hansjörg Wyss provides a fantastic opportunity to use the many different scientific competences and skills here in Zurich to develop new medical and robotics products,” says ETH President Ralph Eichler. The new research centre will be based at both ETH and the University of Zurich and will be co-directed by professors Roland Siegwart (ETH Zurich) and Simon P. Hoerstrup (UZH). “Combined with the excellent basic research at the University of Zurich and ETH’s proven strength in technology development, the Wyss Translational Center will allow our two institutions to assume a very strong position among the international competition,” states Michael O. Hengartner, rector of the University of Zurich.

From research to product

ETH Alumnus Hansjörg Wyss with the two WTZ Co-Directors , Prof. Roland Siegwart (right) and Prof. Simon P. Hoerstrup.

Within the four starting research projects, the two partner institutions are aiming to develop new medical treatments, prototypes and innovative products over the coming years in order to improve the lives of patients and healthy people. An overview of the objectives of the four research projects:

Zurich Life Matrix: Development of in-vitro engineered human tissues that can regenerate and grow along with the organism. For example, scientists are growing blood vessels and heart valves in laboratories from human cells that can evolve in parallel with the heart (e.g. during the growth stages of a child) and have the capacity for self-repair. Existing solutions are usually of a non-living, prosthetic nature and, as a result, lead to complications that require surgical re-interventions often associated with substantial morbidity and mortality.

Zurich Heart/Ventricular Assist Devices: Development of innovative heart support pumps (ventricular assist devices). Many people today suffer from life-threatening heart problems. Artificial heart pumps support the diseased failing heart allowing patients to enjoy a good quality of life in the long term despite the lack of suitable donor hearts. However, there is still much room for improvement related to the biocompatibility, control, ergonomics and size of existing heart support pumps.

Zurich Liver: Development of innovative extra-corporeal perfusion systems. This will allow, for instance, a part of a patient’s liver to be grown outside the body and be transplanted back into the patient. This process would enable patients with serious liver diseases such as cancer to generate their own donor material and significantly decrease the demand for donor organs while increasing patient safety at the same time. The process could then be applied to allogenic transplantations and pave the way for one donor liver benefiting more than one patient.

Zurich Eye: Development of a camera-based positioning system that automatically creates maps of the environment and enables precise positioning. This system is intended to help autonomous vehicles and aircrafts navigate independently in disaster operations, transport and agriculture, and support people in various tasks.

This article originally appeared on ETH News.

The cardiologist sits in the control room next to the operating theatre and uses a joystick to steer a catheter through the patient’s blood vessel into the heart’s chambers to treat the cardiac arrhythmia precisely. With this robot-controlled surgical system, Phocus, the ETH spin-off Aeon Scientific won over a panel of 15 judges at this year’s Swiss Technology Award, presented last Thursday at the Swiss Innovation Forum in Basel. The company from Schlieren won the prize in the Start-up category. “We are delighted that our work has been recognised and appreciated,” said Dominik Bell, CEO of Aeon Scientific. “The award will help us market our product and find new investors and staff.”

Precise guidance with magnetic fields

Aeon Scientific originated from ETH Zurich’s Institute of Robotics and Intelligent Systems (IRIS). The start-up’s work focuses on making conventional surgical procedures safer and simpler. They develop devices that use magnetic fields to steer instruments remotely with millimetre precision inside the human body. The foundations were laid by the team of ETH professor Bradley Nelson, a co-founder of Aeon Scientific. The scientists began their research into a magnet-controlled surgical system at IRIS in 2003, before establishing the spin-off in 2010. The first Phocus system will be put into operation in January 2015 in Zurich.

Bell believes this steering system based on magnetic fields could also be used in other areas of medicine. He is hoping that the company can establish a number of other robot-controlled medical treatments, not just for cardiology. He says that magnetic forces could be used to steer a wide variety of instruments such as catheters, guidewires and endoscopes, or even capsules containing active ingredients, directly to the source of an illness within the body.

Robohub is an online platform that brings together leading communicators in robotics research, start-ups, business, and education from around the world. Learn more about us here. If you liked this article, you may also be interested in:

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Illustration of the different micro-actuators that can be coated with active compounds. (Illustration: Peters C et al. Advanced Functional Materials 2014, reprinted with permission of Wiley.)

Researchers have developed improved forms of tiny magnetic actuators thanks to new materials and a microscopic 3D printing technology.

Scientists have been conducting research on micrometre-sized actuators that one day may make it possible to transport drugs or chemical sensor molecules to specific locations throughout the human body. Researchers at ETH Zurich have now taken the development of such micro-devices a crucial step forward: a new production technology and new materials have made it possible to manufacture tiny actuators in any form and optimise them for future applications.

The elongated actuators elements, which can move through liquids, possess a helical shape and are magnetic. They are driven by an external rotating magnetic field; they align themselves along the magnetic field lines and rotate about their longitudinal axis. Due to their helical shape, they are able to swim forward through liquids.

When applying conventional fabrication techniques, the magnetic properties of these micro-objects depend on the shape of the devices themselves. This restriction made it difficult for researchers to develop  actuators with precise control and directional stability, as doctoral student Christian Peters from the group led by Christofer Hierold, Professor of Micro and Nanosystems, explains: “Previously, these elements wobbled as they moved forward, and they were less efficient because their magnetic properties were not ideal. We have now developed a material and a fabrication technique with which we can adjust the magnetic properties independent of the object’s geometry.”

Microscopic 3D printer

The scientists used a light-sensitive, bio-compatible epoxy resin, in which they incorporated magnetic nanoparticles. In the first part of the curing stage, they exposed a thin layer of this material to a magnetic field. This field magnetised the nanoparticles, leading to a particle re-arrangement in form of parallel lines. The orientation of these lines determines the magnetic properties of the material. The researchers then manufactured the tiny elongated structures out of the modified epoxy film via two-photon polymerisation. This technique is similar to a microscopic 3D printer: a laser beam is moved in a computer-controlled, three-dimensional manner within the epoxy resin layer, thus curing the resin locally. Uncured areas can then be washed away with a solvent.

This technique allowed the researchers to manufacture helical structures 60 micrometres in length and nine micrometres in diameter, and with a magnetisation perpendicular to the longitudinal axis. A conventional manufacturing method would not have allowed the production of an object with such magnetic properties, as the preferred magnetisation is usually in the direction of the longitudinal axis of an object, like a compass needle. The new actuators can be controlled precisely, they swim nearly four times as fast as previous elements, and they do not wobble.

New forms with larger surfaces

Previous micro-actuators usually took the shape of a corkscrew (helix), but thanks to the microscopic 3D fabrication technology the ETH scientists were able to produce modified shapes. In the study they fabricated structures similar to spiral-shaped, twisted strips and double-twisted wires. Tests show that these forms swim as fast as corkscrew-shaped actuators, but the new shapes differ from the latter in that their surface is two to four times larger. “This makes the actuators more interesting for certain applications,” says Salvador Pané, research associate in the group led by Bradley Nelson, Professor of Robotics and Intelligent Systems.

If such elements are to carry medications or chemical sensor molecules to specific locations in the body, the actuators must be coated with the corresponding molecules. And the larger the element’s surface, the larger the quantity of materials that can be transported. The researchers demonstrated that it is possible, in principle, to coat the structures with interesting biomedical materials by connecting antibodies to the surface of the spiral motors.

“But it is not just about swimming micro robots,” says Peters. “The new technology can also be used when other micro-objects have to be manufactured with specific magnetic properties.” The work is the result of many years of joint research between the two professors in the Department of Mechanical and Process Engineering in the fields of microsystems technology and micro-robotics, adds Pané. The group led by Nelson has many years’ experience in the fabrication and application of magnetic micro robots, and the group led by Hierold has a strong competence in the integration of new materials into microsystems.

This article originally appeared on ETH News. 

Literature reference

Peters C, Ergeneman O, Wendel García PD, Müller M, Pané S, Nelson BJ, Hierold C: Superparamagnetic Twist-Type Actuators with Shape-Independent Magnetic Properties and Surface Functionalization for Advanced Biomedical Applications. Advanced Functional Materials 2014. 24: 5269-5276, DOI:10.1002/adfm.201400596

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ARMin neuro-rehabilitation device.

In this pair of video lectures, Robert Riener presents his team’s research efforts in the field of rehabilitation robotics, and describes the vision behind Cybathlon, the competition for robot-assisted parathletes.

Novel robots for gait and arm rehabilitation

Patients who have limited use of their arms or legs due to stroke or spinal chord injury require intensive therapy to help them rehabilitate. This rehabilitation process is long, exhausting and expensive, and requires intensive therapy with specialists. With robotic technology, many of these challenges can be overcome.

Systems such as the Robot-Aided Gait Training enable patients to start intensive therapy right away, and for longer hours. The ARMin neuro-rehabilitation device helps stroke patients regain physical capabilities; research results show that patients subjected to ARMin training heal faster than patients working with therapists alone.

These devices involve intense human-robot cooperation and therefore have been developed according to human-robot interaction best practices. Future research will be focused on improving the effectiveness of robotic rehabilitation devices and their overall use in the medical field.

You can download the .pdf presentation here: Novel Robots for Gait and Arm Rehabilitation.

Riener R. IJARS Video Series: Novel Robots for Gait and Arm Rehabilitation [online video]. International Journal of Advanced Robotic Systems, 2014, 11:V2. DOI: 10.5772/59833

Cybathlon 2016, The Championship for Robot-Assisted Parathletes

Research labs around the world have been focused on developing novel assistive technologies such as wheelchairs, exoskeletal and mechatronic devices to help patients with spinal chord injuries in their daily life activities. There is still a long way to go before these kinds of devices will enable complete movement for these patients.

That is why Dr. Robert Riener and his team of collaborators are organising a special kind of event – Cybathlon 2016 – similar to the paralympic games. During Cybathlon, participants will compete in six disciplines while using wheelchairs, exoskeletons, brain and muscle stimulation devices, and other technologies.

The goal for researchers is to learn the strengths and the weaknesses of these devices and ultimately make them more effective for patients. The project also aims to promote wider use of robotic technology solutions in the fields of medical treatment where extensive physical therapy and assistance is required.

Riener R. IJARS Video Series: Cybathlon 2016, The Championship for Robot-Assisted Parathletes [online video]. International Journal of Advanced Robotic Systems, 2014, 11:V3. DOI: 10.5772/59837

Robert Riener is Full Professor for Sensory-Motor Systems at the Department of Health Sciences and Technology, ETH Zurich. He has been Assistant Professor for Rehabilitation Engineering at ETH Zurich since May 2003. In June 2006 he was promoted to the rank of an Associate Professor and in June 2010 to the rank of a Full Professor. As he holds a Double-Professorship with the University of Zurich, he is also active in the Spinal Cord Injury Center of the Balgrist University Hospital (Medical Faculty of the University of Zurich).

His current research interests involve human motion synthesis, biomechanics, virtual reality, man-machine interaction, and rehabilitation robotics. He has authored and co-authored more than 400 peer-reviewed journal and conference articles and 20 patents. He is a member of several scientific societies (e.g., IEEE/EMBS, DGBMT/VDE, IFESS) and an associate editor of several scientific journals. For his development of the arm therapy robot ARMin, he was awarded with several prizes including the humanTech Innovation Prize and the Swiss Technology Award. He was awarded also with the IEEE TNSRE Best Paper Award 2010 and the euRobotics Technology Transfer Awards 2011 and 2012.

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Brad Nelson heads the Institute for Robotics and Intelligent Systems at ETH Zurich, where they focus on creating these nano devices inspired by the biological mechanisms of bacteria such as E. coli and salmonella.

Brad Nelson. Photo credit: ETH Zurich/Stéphanie Marie Couson

Brad Nelson is a Professor of Robotics and Intelligent Systems at ETH Zurich – The Swiss Federal Institute of Technology, Zurich. His primary research focus is on microrobotics and nanorobotics emphasizing applications in biology and medicine.

He has been the Department Head of Mechanical and Process Engineering at ETH, Chairman of the ETH Electron Microscopy Center, and is a member of the Research Council of the Swiss National Science Foundation. He is also a member of the board of directors for three Swiss companies.

More info:

Institute of Robotics and Intelligent Systems (IRIS)
Multi-Scale Robotics Lab (MSRL)
Brad Nelson’s Homepage
Brad Nelson’s TedX Talk

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A camera man gets up, close, and personal with the human and machine actors on the “Sparked” set.

If you thought “SPARKED” – the new short film by Cirque du Soleil, ETH Zurich, and Verity Studios – is too real-looking to be CGI, you were right. But why go to all the trouble of using quadrotors to get those lampshades dancing in the air for real? We asked Bill Keays, Science and Technology Advisor at Cirque du Soleil, to give us an insider’s perspective about Cirque’s motivation for the film and how it came together.

Bill Keays on the SPARKED film set.

[Robohub] What was the inspiration for the film?
[Keays] The combination of autonomous flying machines with Cirque du Soleil magic was so evidently bursting with potential we committed ourselves to make something original together not knowing what it would be at first. An iterative creative process ensued involving all participants, and what emerged was a wonderful script that carried the talent from both sides of the formula to a whole new level.

Who are the main partners on the project? 

It was a highly democratic and highly collaborative process. Raffaello D’Andrea of ETH Zurich and Verity Studios, and Welby Altidor of Cirque du Soleil were the project leaders, but the true collaborative nature of this project is reflected in the fact that no participant roles are specified in the credits.

Who initiated the project? 

The very first discussions were held between Prof. Raffaello D’Andrea at ETH Zurich and myself as Science and Technology Advisor at Cirque du Soleil in March 2012. After ongoing discussions and considering various options, the two organizations eventually committed to a creation project in January 2014.

The “Sparked” film set. The shoot took place in the Flying Machine Arena at ETH Zurich, a portable space devoted to autonomous flight.

Why was the film made?

For Cirque the project demonstrates a whole new avenue for channeling creativity. It allows Cirque to reach a new audience externally and provides inspiration internally to push the creative envelope in new directions.

As such is a highly effective, multifaceted communications vehicle, and it will certainly be submitted for competition.

What were the production costs? 

The large bulk of the cost came in terms of human resources split between three organizations. The exact figures cannot be known.

How long did the project take from first concept to finished film? What were the major steps/milestones?

The whole project, from go-ahead to YouTube release, took under 8 months. It was a back and forth process whereby content was driven by discussions between Cirque, Verity, and the film director. Through this method we progressed through initial concept design, script development, set and prop design, and finally the shoot, with intense hardware and software development taking place throughout. The product was then handed off to post production and then to distribution.

Setting up before a flight scene.

Who designed the lampshades? The photos show researchers from ETH and Verity fitting the quads with them. Did you provide dimensions to props experts and iterate? How did that process work?

It was indeed an iterative process. The lampshades were designed and produced by the creative team at Cirque in Montreal who used their own quadrocopters for flight tests to ensure that they would be compatible with the flight environment at ETH Zurich. Guidance from the ETH and Verity teams was indispensable of course.

Was the actor controlling the quads with hand motions (via Kinect)? Or was this pre-programmed and choreographed? At times it looks like he is ‘conducting’ their movements …

The Flying Machine Arena fully possesses the ability to control the flying machines with a Kinect or other similar devices, or even hand gestures. But given that this is a movie production, the movements of the actor and the flying machines were choreographed as is the convention in film practice.

Was there any CGI at all in the film? How much is real?

None whatsoever, it’s all real; and even though it looks terrific in the movie, this pales in comparison to seeing it in the round. It was mindboggling to watch live.

Has Cirque worked with robots before?

Yes, Cirque has experimented with robots in the past, but never flying ones.

What were the biggest challenges of putting live actors together with the quads on stage?

Given that this is such an unusual circumstance for making a movie, we didn’t know how our lead actor would react to the flight environment. But the high precision of the flying machines and terrific expertise of ETH Zurich’s Flying Machine Arena staff quickly inspired confidence. By the second day, remarkably, our actors, both human and mechanical, were moving about the set with terrific ease, paying little attention to each other.

Was safety ever an issue?

The design of the lampshades was convenient in that it shielded the blades of the quadrocopters, thus making them far less likely to strike anyone or anything. There were a couple of crashes and a few low passes, but at no point was there any real apparent danger.

What about lighting?

Believe it or not, all the scenes with the flying lampshades are completely lit by the lampshades themselves! Another fortuitous design feature.

Changing batteries.

Were there any other challenges?

The rapid power consumption of the flying machines meant that battery changes would be frequent. With time, the switch-overs began looking like Formula 1 pit stops, performed with great speed and precision.

What was it like for the researchers from the lab to have to ‘perform’ for the camera? How long did they have to rehearse before you were ready?

The lampshades arrived in the weeks prior to the shoot so there was time for Verity Studios and ETH Zurich to fully test their aerodynamic abilities, and to run through the choreography. In the days preceding the shoot we performed flight tests according to the story board and had one practice day with the lead actor. However, due to the extreme time constraints imposed by the film crew, the control software had to be designed such that flight plans could be altered at a moment’s notice to meet specific requests from the director. This proved to be an invaluable tool and was instrumental in completing the shoot in the allotted time.

Had your previous work (e.g. demos, presentations) prepared you for working with quadrotors on a film set?

Absolutely, the Flying Machine Arena team had performed extensively with flying machines in public spaces and conferences (including TED), so much of this experience transferred well onto the movie set.

An early flight test in the Flying Machine Arena.

The quadrotors peek through in the film at times, as do the retro reflective markers for the motion capture system – was this intentional?

It is true that the quadrotors are sometimes visible, but the visual quality of the movie is so overwhelming that it is difficult to remain focused on technical bits. We actually liked the fact that they were occasionally visible; as sort of a wink to those of us who are knowledgeable about them.

With previous demos, the quadrotors played a leading role – but in this film, they are literally hidden behind lampshades. How does it feel to see them step back into a supportive role for this film?

But the flying machines are not hidden. They are in dress like all actors in this movie; they have character, motivation and certainly no lack of presence. As the devil’s advocate, I would be inclined to challenge the assumption that they are playing a supporting role.

Why not just do it with CGI?

There are at least two good reasons:

First of all, because the Flying Machine Arena is not about CGI. It’s about control systems, aerodynamics, and sophisticated algorithms that yield a physical manifestation of uncommon beauty.

The second reason is because you can’t do CGI in front of a live audience and Cirque du Soleil is in the business of live entertainment. Even though this extraordinary little movie is a gem in its own right, it is primarily the proof of concept for something far more powerful; something that must be seen live.

All images credited to the “Sparked” team. For more insight on the film see also New quadrocopter video points to a future for flying machines in entertainment by Markus Waibel of Verity Studios. 

We’ve seen robots on stage before: Humanoids have been featured in theater productions in Switzerland, Austria, and Japan, and industrial robots have played parts in dance performances and other staged events. Flying robots have also played a theatrical role, for example in Shakespeare’s A Midsummer Night’s Dream at Texas A&M, a dance set to a Schubert piano trio at MIT, as well as in advertising. Some robots have even gone pro: Robothespian was designed for acting and is rented out for performances.

But the dance between human and machine has never looked quite like this .

The film’s main plot is straight-forward: Lamps in a repair shop magically come alive, rising from their stands to sneak up on an unsuspecting repairman. As the magic unfolds, and the repairman discovers that the everyday objects of his trade have become animated and full of character, viewers become witness to the evolving dance between man and technology.

Everyone on the team, including myself, was impressed by how well the film captures the stunning, at times hypnotic visuals of the flying lampshades. Everything you see is real — no CGI, wires, or speed-ups/slow-downs were used in the film. 

So how did the lampshades come alive?

This short film, titled “Sparked”, was produced in collaboration between researchers at ETH Zurich’s Flying Machine Arena, their spin-off company Verity Studios, and entertainment company Cirque du Soleil; in other words, it’s quadrocopter magic that makes the lampshades fly.

The film marks a step change from previous work by ETH Zurich’s Flying Machine Arena team, catalyzed by their new spin-off company Verity Studios, which also gets credit for designing the quadrocopters’ choreography. Here, in spite of their computer-controlled precision flights, the flying machines become robot actors that are individuals with their own personalities: Pomponette, with her tassels bustling in the propellers’ airflow; the Medusa with its bizarre tentacles waving in the wind; the Runt, sleek and fast but still glowing and twitching from the electric shock. And Lady Purple, absent from most of the film because of her intractable aerodynamics.

Flying machines up, close, and personal

One of the most striking aspects of this film shoot was watching our actor, Nicolas Leresche, interact with the flying machines. Much of this interaction was captured on camera — and you can see the results in the film, in particular the moment of ‘first contact’ — but, for me, it was what happened off-camera that was most revealing.

Naively unjaded by their joys and dangers, this was Nicolas’ first experience with quadrocopters. As he began interacting with them, tentatively at first, and then — in a matter of seconds — more confidently, even playfully, it became crystal clear that I was not merely observing a human using a robotic tool.

As the quadrocopter’s onboard controller pushed back against Nicolas’ hand, immediately reacting to match his actions, it became apparent that the two interacted in a way we don’t usually get to interact with technology. The interaction here was physical and dynamic, and clearly intuitive for Nicolas. There was no noticeable learning curve, no need for manuals or explanations.

But what was most striking about this interaction was the result. Within seconds, Nicolas had established a deep, almost animate connection with the flying robot actors. As their dance developed, driven by the autonomous machines’ choreography and Nicolas’ script, and became ever more fluid and natural, it became clear that what we were witnessing was a relationship in its making; one of mutual respect and, at the same time, confidence and trust. And once there was trust, magic happened.

In his own words:

Actors think that they are the ones who make objects move. I think that, on the contrary, it’s the objects that make us move. In the case of drones, even more so! They are companions (in an etymological sense), confrères, brothers.

Within hours the entire film crew had become comfortable with the flying machines hovering nearby or brushing past them as they swooshed through the air. On one occasion, a mis-timed dolly motion led to a flying machine hovering just centimeters above the camera man, who continued with his work unfazed. On another occasion, when Nicolas missed his cue, he bumped into one of the flying machines. But they just jostled past each other and continued on with their choreography as if nothing exceptional had happened. On yet another occasion, a drone collided with the moving camera without disturbance.

The only damage during the entire two-day shoot was a single broken lamp, knocked over by one of the quadrocopters’ airflow.

Safety

I have no doubt that this level of confidence and comfort with the technology can in no small part be attributed to the system’s reliability. In spite of the packed shooting schedule (a total of 40 shots over two days) and the high complexity of the project (for example, designing lighting conditions using more than 60 light sources including some moving through space), production went smoothly, and importantly for the quadrocopter team, the flying machines did not add any significant delay. Battery swaps and on-the-spot changes to the choreography were efficient and quick, never exceeding a few minutes. Kudos to the excellent film team from who’s mcqueen for brilliantly doing their part to keep the production on schedule.

Collaboration

One aspect that made this project particularly enjoyable was the collaboration with creatives at Cirque du Soleil. From the start there was a lot of excitement about the potential of this technology for entertainment not just at ETH and Verity Studios here in Zurich but also at Cirque in Montreal. Everyone shared the view that the flying machines could be used to amaze audiences and to tell wonderful stories. What ensued was a collaborative, iterative creation process that culminated in a script and a set design that were imaginative to Cirque du Soleil standards, while exhibiting the abilities of the quadrocopters in their full splendor.

As it turned out, figuring out what is easy and what is difficult to achieve with autonomous quadrocopters can be quite counter-intuitive. Having researchers and creatives on both sides collaborate on the key creative elements of the story from the early phases of the project therefore proved invaluable to its success.

Next steps

Why go to all this trouble? We’ve all seen the amazing things CGI can do on film. I love films and movies, how they can condense experience and add life to our most impossible dreams. But nothing compares to the real experience of getting up, close, and personal with robot actors yourself.

What’s next? Our audiences over the past years have had more ideas than we can count. At this point, only one thing’s for sure: They all want to see more flying robot actors.

Some more snapshots from the film shoot below for your viewing pleasure:

All images credited to the “Sparked” team. Markus Waibel is a former member of ETH Zurich, a co-founder of Verity Studios, and one of the contributors to “Sparked”.

Guest talk in the ShanghAI Lectures, 2011-11-17

Artificial ontogenetic development has been nicely demonstrated by many computer simulation studies in the past. There are, however, still a number of technical challenges in bringing it to the real world. In this presentation, I will introduce some potential solutions to this challenging problem, solutions that stem from soft robotics research. More specifically, we demonstrate how autonomous construction, autonomous body extension, and autonomous robot climbing locomotion can be achieved by exploiting unconventional soft material such as Hot Melt Adhesives.

The ShanghAI Lectures are a videoconference-based lecture series on Embodied Intelligence, run and organized by Rolf Pfeifer (from 2009 till 2012), Fabio Bonsignorio (since 2013), and me with partners around the world.

http://www.youtube.com/watch?v=NV3wxfJ0gKg

Slides

The ShanghAI Lectures have brought us a treasure trove of guest lectures by experts in robotics. You can find the whole series from 2012 here. Now, we’re bringing you the guest lectures you haven’t yet seen from previous years, starting with the first lectures from 2009 and releasing a new guest lecture every Thursday until all the series are complete. Enjoy!

The idea was developed around the following premises:

• The regulatory picture is murky and evolving – note that the FAA will likely miss the 2015 deadline for setting a UAV regulation, and that tethered aircraft are exempt from these rules
• Accountability is important – most people are not happy to be the target of camera that is being flown by an unseen operator

The solution is a tethered, GoPro-fitted quadcopter with onboard algorithms that let it fly instantly and virtually under any conditions, without relying on piloting skills, GPS working or wifi failing.

http://youtu.be/A0ccn9NeZow

Fotokite is designed to be launched and fully operational in one minute. To the user, flying the camera is as simple as holding a kite, and framing the picture is as easy as rotating your hand-held monitor. The tether provides visual accountability for bystanders and property owners.

Fotokite. Credit: Robert Ladig.

The man behind the project, Sergei Lupashin, is a TED Fellow with 10+ years of autonomous systems experience and has assembled an impressive team that includes robotics heavy-weight Raffaello D’Andrea as an advisor. The project is supported by the Swiss National Centre of Competence for Research in Robotics (NCCR), which is also a supporter of the Flying Donkey Challenge.

Already there are several concepts that enable a drone to autonomously follow and film a moving object (AirDog and Hexo+). However, the Fotokite seems particularly well suited for use in media, to provide birds-eye view while allowing those around the device to immediately identify the camera operator. Though its price is still unknown, it seems like a  cool tool that will surely be added to many reporters’ inventory one day soon.

Video and image courtesy of Fotokite.

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Noonee® is a new Start Up company coming out of research in robotics in Switzerland. Aimed at solving healthcare problems within the manufacturing industry, noonee adopts a Chairless Chair® approach.

Within the manufacturing industry, keeping employees healthy has been a major concern and challenge for many companies around the world for a long time. Jobs often involve spending long periods of time bending and crouching and as a result can leave staff with substantial back and knee problems. Of 215 million industry sector workers in the EU, a staggering 85 million are reported to suffer from muscle related disorders. Market solutions that are currently available may also pose problems as they limit short term tiredness by taking all the weight of the user, which can lead to muscle weakening. What is needed is a product that can support staff working on production lines while keeping them healthy.

Coming out of NCCR Robotics lab, the Bio-Inspired Robotics laboratory at ETH Zurich, Switzerland, noonee® is a revolutionary start-up business aiming to address this significant social issue that previous solutions have not dealt with successfully. The idea is to provide an exoskeleton that supports the weight of the user only when they feel tired , rather than continuously taking on this weight – meaning that the wearer is using their muscles and actively, rather than passively, sitting.

The “chair” is not a chair as we know it, but more of an exoskeleton for the legs with a belt to attach it to the hips and straps that wrap around the thighs. The slim structure has joints that allow the wearer to move freely, but when the wearer is in a position they wish to stay in for a long time (e.g. crouching under a car on a production line), this position can be fixed, meaning that the wearer does not need to use the same muscle groups for long periods of time to hold the position. The advantage of such a structure is that it can be worn anywhere and can also be used when standing and walking. This reduces the space required as compared to a traditional chair and reduces the hassle when compared to other solutions, such as chairs that are strapped to the user. The Chairless Chair® is currently still in prototype and the current version requires the user to fix a position by crouching down into the required position and pushing a button. It is hoped that future iterations of the Chairless Chair® will be actuated to allow the system to become intelligent and understand the intention of the user, allowing it to be fixed into position without any additional input from the wearer.

If you’re interested and want to be a part of prototype testing, check out their website and get in touch. Feel free to also ask questions in the comment section below.

Robohub is an online platform that brings together leading communicators in robotics research, start-ups, business, and education from around the world. Learn more about us here. If you liked this article, you may also be interested in:

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• Introducing the Cybathlon
• Rehab robots, smart prostheses and exoskeletons to reach $1.8 billion by 2020

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

UPDATE 04/03/2014:

In this video update, we show that a quadrocopter can be safely piloted by hand after a motor fails, without the aid of a motion capture system. This follows our previous video, where we demonstrated how a complete propeller failure can be automatically detected, and that a quadrocopter can still maintain stable flight despite the complete loss of a propeller. 

In the earlier video, we relied on an external motion capture system to measure the quadrocopter’s position and orientation.  By moving more of the algorithm onto the vehicle, the quadrocopter can now be piloted by hand after the failure. The algorithm is executed on the quadrocopter’s onboard micro-controller, and the only sensors required are the quadrocopter’s angular rate gyroscopes. We use blinking LEDs, mounted on the quadrocopter’s arms, to indicate a virtual yaw angle, so that the pilot can control the vehicle with the same remote control commands after the failure. As an alternative to the LED system, an onboard magnetometer could be used to track the vehicle’s yaw angle. Alternatively, by using more sophisticated algorithms, the system could be made to work using only the rate gyroscopes.

ORIGINAL STORY 02/12/2013

The video in this article shows an automatic failsafe algorithm that allows a quadrocopter to gracefully cope with the loss of a propeller. The propeller was mounted without a nut, and thus eventually vibrates itself loose. The failure is detected automatically by the system, after which the vehicle recovers and returns to its original position. The vehicle finally executes a controlled, soft landing, on a user’s command.

The failsafe controller uses only hardware that is readily available on a standard quadrocopter, and could thus be implemented as an algorithmic-only upgrade to existing systems. Until now, the only way a multicopter could survive the loss of a propeller (or motor), is by having redundancy (e.g. hexacopters, octocopters). However, this redundancy comes at the cost of additional structural weight, reducing the vehicle’s useful payload. Using this technology, (more efficient) quadrocopters can be used in safety critical applications, because they still have the ability to gracefully recover from a motor/propeller failure.

The key functionality of the failsafe controller is a novel algorithm that I developed as part of my doctoral research at the Institute for Dynamic Systems and Control at ETH Zurich. This new approach allows such a vehicle to remain in flight despite the loss of one, two, or even three propellers. Having lost one (or more) propellers, the vehicle enters a continuous rotation — we then control the direction of this axis of rotation, and the total thrust that the vehicle produces, allowing us to control the vehicle’s acceleration and thus position.

Even if the vehicle can no longer produce sufficient thrust to support its own weight, this technology would still be useful: one could, for example, try to minimize the multicopter’s velocity when it hits the ground, or steer the multicopter away from dangerous situations such as water, or people on the ground.

This control approach can also be applied to design novel flying vehicles — we will be releasing some related results soon.

This technology is patent pending.

For more information, have a look at the Flying Machine Arena website, the IDSC research page, or just post your question in the comments below.

If you liked this article, you may also be interested in:

• Three new quadrotor videos demonstrate agile control and the power of machine learning
• Live at TED Global 2013: Tweets, photos and video for quadrotor fans
• Behind the scenes at TED Global: Raffaello D’Andrea and team demo amazing quadrotor “athletes”
• Quadrocopters learn from prior experience to improve slalom flying

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

TEDGlobal 2013 in Edinburgh, Scotland. June 12-15, 2013. Photo: James Duncan Davidson

In this 4^th interview of our four-part ECHORD series, conducted last June, Sascha Griffiths from TUM talks to Raffaello D’Andrea, Professor of Dynamic Systems and Control at ETH Zurich and technical co-founder of Kiva Systems. The series explores success stories and common obstacles in industry-academia collaborations in the field of robotics, and examines the differences  between these collaborations in the US, Europe and Asia.

[Sascha Griffiths]
Can you describe your background a little? I am especially interested in your transitions between industry and academia. 

[Raffaello D’Andrea]
After getting my PhD at Caltech I became an assistant professor at Cornell University, where I was for ten years. I started the RoboCup program there and we had a RoboCup team that competed there for five years. We won the world championship four times. My area of research is dynamics and control systems, so, for me, robotics was kind of an application area. It’s a good system design problem.

While on sabbatical at MIT in 2003, I met Mick Mountz, an entrepreneur, and he told me about the problem he was trying to solve: distribution. That is when I decided to quit my sabbatical at MIT and join forces with him and Pete Wurman to start Kiva Systems.

In 2008, I officially moved to ETH Zurich but remained on as an advisor at Kiva, and I’ve been here since.

Would you say that Kiva Systems stemmed directly from your research?

No, I wouldn’t say directly. We did fundamental research on controlling robots and controlling dynamical systems. Kiva Systems has a connection to that, but it is not as though my research directly led to Kiva Systems. It was more that the knowledge, experience, and architectures that I learned during RoboCup transitioned into Kiva Systems.

Prof. Asada also mentioned in our interview with him that he thinks the practical character of RoboCup is really important. Do you think that is a good starting point?

Yes, absolutely.  A lot of our first hires at Kiva Systems were former RoboCup students from Cornell University. They learned great skills while they were doing these types of competitions:  how to work in teams and how to work at mechanical, electrical and computer science level issues. There are tight deadlines. You want to get the job done. There are a lot of parallels between doing things in competitions and being successful in the marketplace, and I think that is a great preparation.

Have you been in involved in academia-industry collaborations?

No, in fact I probably have a different view than most people on this topic, especially from most people in Europe. My thinking has been shaped more by the American system, where academia’s focus is on fundamental research. I would like to see more effort to strengthen academia and industry and I think the best way to do it is through entrepreneurs.

What do you think academia can offer to industry in a collaborative project? Do you think there is a reason why collaborations need to take place?

I do. I know a lot of colleagues who work really well with industry. Industry is full of interesting research problems, and it is full of folks who are interested in creating short-term, medium-term, and maybe even long-term gains. So, for them it makes sense to partner with industry. That is one way to do it. I tend to favor the other approach, which is to do fundamental research, and if it is good work, then attract the interest of entrepreneurs who are willing to learn about the new technology. There are also technologists who have an entrepreneurial spirit, who team up with domain experts and figure out how the technology could be used.

Where do you see the hurdles when technology is transferred from academia to the industry? Why do you think the transfer process is so slow?

The reward system in academia is very different to the reward system in industry. In academia, especially if you are doing fundamental research, robustness of what you are doing is not really the primary concern. It is new algorithms, new designs … and you don’t have to worry too much if it doesn’t work all the time. Of course in industry, especially with automation, that is a huge criterion. Systems have to work under different conditions; and they have to work all the time, 24/7. A lot of the time, it is about figuring out what is just a lab demo versus what is ready to be deployed in industry.

How do you think one could speed up the process of getting from the demo to a product that is commercially viable and achieving the robustness you mentioned?

Investment. Having entrepreneurs who understand where the technology is at and what is required to commercialize it, and who seek investment to actually do that process. This investment could come from private money or it could come from public funds, but it’s investment that speeds up the process.  I would favor that mechanism more than just giving money to the industry and academia for collaboration and say “commercialize this technology”. If you have entrepreneurs to lubricate this process, it will speed it up a lot.

You have already mentioned the reward systems. When you think of academic and industrial partners collaborating, how can they measure the success of their collaboration in your opinion?

I think one thing is patents, which are rewarded both in industry and academia. But I also think that a big metric of success is the students that are trained. A lot of the time, if it is a real collaboration between academia and the industry, those folks will transition into industry. I think you have to take a longer-term view than just a few years. You have to understand that if there is a relationship being built, it can form a pipeline of really talented PhDs with skills in that particular area, who then often go to work for that company. That is a huge plus, which is not immediate, but will have its benefits in the medium term.

How would you measure technological progress?

That depends on which way you look at it. If you are viewing it from an academic perspective, again, the reward is if it is getting accepted in top peer-reviewed publications. From the industrial side, the question is whether it is a product. And there is some stuff in between. I think you have to look at it on a case-by-case basis. I don’t think there is a simple metric. You have to look at the technology: how many years will it take to be commercialized? What impact will it have? Will something else replace it?

Do you know of something at the moment, for example, in the research with quadcopters, where you think that it has really improved the technology?

I think the limiting factor is not the technology, it is good business models. That is what is missing. The technology is quite far along … I think that once people figure out what the right business models are to commercialize this technology, things will move very quickly.

Do you see different models of technology transfer in North America and Europe?

I know Switzerland and I know the United States, and I think they are similar in many ways. If you develop technology at ETH, and it is done during research that is being funded, the inventors get a fraction of it, and the university gets a fraction of it. If students want to commercialize a technology themselves, they can license the technology from the university. If you personally don’t, the university can license it on your behalf. They get a certain fraction of the profits, the inventors get a certain fraction… That is also how it is done in the United States. I think that works well. It has the right incentives; it is not too onerous, where the university claims everything, which disincentives the inventors from doing it because they do not get any benefit. On the other hand, it is only fair that the university should get some rewards for developing technology and it is really leaving it up to the entrepreneurs to take these ideas and commercialize them. I think in that way it is similar. I cannot really talk about the rest of Europe.

Do you see any current trends in robotics, where you think real progress is being made towards commercialization?

I think people are looking at consumer robotics. But I think in the short term, it is going to be traditional manufacturing, helping existing businesses improve their operation through automation and robotics. That is where the potential is, simply because it is still a semi-structured environment. If you sell something to a consumer, it has to work in so many different situations. Every home is completely different. Whereas, if you are selling to a business that is trying to improve their manufacturing capabilities, for example, they have leeway on changing the way things are done, rearranging things, instrumenting things to help their operations. So, that is where I think you will see the big in-roads in robotics and automation.

Are we currently in a situation of increasing the market share and selling more, or are we seeing real progress?

No, I don’t think the market size is increasing. Before, it did not make sense to use automation in certain areas, but now the technology is improving in such a way that it does make sense to do so, and to do so in more industries.

Do you think academics lose interest as soon as something reaches market readiness?

Yes, I think that is the case. Academics are interested in doing fundamental research, and there is a different set of values and constraints when you want to commercialize something. For example, robustness – which I think is actually an interesting topic itself – has a lot of interesting research problems associated with it. They tend to be more at the system level. And I think only a few people are really interested in doing those sorts of things. So, I think, for the most part, academics lose interest. Not all, but a fair amount do.

Do you think that is a good or a bad thing?

I do not think it is a bad thing. I think that, again, you need something in between university research and commercialization to facilitate this process. There are many ways to do that. In Germany and in a lot of other European countries, there are strong industry-university collaborations. In the United States, it is more the entrepreneurial folks that are forming the glue. I tend to like the US model best. I think that it enables the quickest transition. Entrepreneurs are the ones who take on the stuff that is not ready for prime time, so to speak, and actually do it. And it takes investment. So, it is not bad that this happens … because without it, you would not get fundamental research done. So, I think that is perfectly fine.

In your TED talk, you talked about science, engineering, and arts coming together. I think you did not mention business and industry as such. Do you see these worlds connecting well or do you think they are all individual communities that tend to not communicate?

I think that they are separate entities, but there are people who are always at the overlap. You need enough of these people to ensure that there is a transfer of knowledge and interests.

Do you think the business, engineering, and science communities communicate enough?

I think they do. They could do more, of course. And I think the right way to do it is to provide the right incentives.

If you liked this article, you may also be interested in:

• The full ECHORD interview series
• Why fostering high-tech innovation and entrepreneurship matters to the economy, and what universities can do about it
• Live at TED Global 2013: Tweets, photos and video for quadrotor fans
• Raffaello D’Andrea on “Do robots kill jobs?”
• Raffaello D’Andrea on “How will robots shape the future of warfare?”
• Raffaello D’Andrea on “What funding scheme is the most conducive to creating a robotics industry?”
• Robots Podcast: Warehouse robots

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Microsoft has been investing in Swiss research for years, and now the US technology company is renewing its longstanding collaboration with EPFL and ETH Zurich. Microsoft will provide one million Swiss francs per year in funding for IT-related research projects at the two universities over a period of five years. The collaboration is a continuation of a project launched in 2008 that focused on embedded technology software solutions and prototypes. The new collaboration will now broaden the areas of computer science and deepen the collaboration between the three partners.

Scientists in Lausanne and Zurich submitted 27 proposals, seven of which were selected by the steering committee. Among the successful projects:

Interacting with flying robots

Otmar Hilliges, a 34-year-old assistant professor, is one of the successful project applicants. The young computer scientist from ETH Zurich studies the interaction between people and computers. For his project, he and Dr. Shahram Izadi from Microsoft Research are investigating how flying robots can work and interact with people in active scenarios. Specifically, they want to develop a platform that enables flying robots to do more than just recognise people and navigate their way around them. Thanks to their algorithms, the robots should be able to react to gestures and touch as well.

Energy-efficient memory systems

At the EcoCloud center at EPFL, Dr. Edouard Bugnion and Professor Babak Falsafi are carrying out research into energy-efficient memory architectures for data centres that can handle huge amounts of data. To do this, they are combining thousands of energy-efficient micro-servers in a way that enables them to access the memories of the other servers with a minimal time delay. The two computer scientists are working with Dr. Dushyanth Narayanan and other scientists from Microsoft Research in Cambridge to develop new applications for this system, known as Scale-out NUMA.

Over the next four years, the Swiss will invest almost CHF30 million to build a new National Centre of Competence in Research for digital fabrication in architecture. The Swiss government and the Swiss National Science Foundation (SNSF) will funnel CHF13.4 million into the project. The centre will be hosted at ETH Zurich, which will contribute an additional CHF15 million as the lead institution; EPFL, EMPA, and the Bern University of Applied Sciences will also partner on the project. Encompassing the disciplines of architecture, computational design, electrical and mechanical engineering, material sciences, and robotics, the investment is an attempt to transform Switzerland’s construction sector from a resource-based industry to a knowledge-based one, and to position the country as an international leader in innovative architecture and building construction.

Coined by the Swiss architecture duo Gramazio & Kohler, “digital fabrication” is a concept for an advanced method of architectural production that uses robotic fabrication to bridge the gap between digital design and physical construction. In a recent interview, Matthias Kohler explains the impact of this approach on architectural design practice: “Nowadays, architects work almost exclusively on computers, but it is still unclear whether and how this affects the design and construction process itself. Here we are looking for new instruments to bring the design, planning and construction phases closer together in order to directly interrelate them.”

Sophisticated computational processes, non-standard material and constructive systems and adaptive strategies for controlling advanced fabrication systems will need to be developed before Switzerland’s construction industry can adopt digital fabrication as its new paradigm. Researchers in multiple fields will also need to develop common standards, interfaces and infrastructure. Knowledge-transfer to industry will be an additional obstacle, as many unanticipated technological challenges will arise when digital fabrication is applied to actual building systems.

Kohler admits there are risks: “It is a large collaboration with several research institutes. At ETH alone, scientists from the departments of architecture, IT, electrical engineering, mechanical engineering and process engineering, and civil, environmental and geomatic engineering are involved. All these disciplines have a different understanding of research. One of the key challenges will be to synthesize these approaches and arrive at innovative methods and results together.”

Where will the money go?
The Swiss are hoping that a full-scale, comprehensive approach to funding the endeavour will help address these challenges. Funding, which can be renewed for up to 12 years, will be directed towards three broad areas of research for its first four years: computational design and building process innovation, non-standard material and constructive systems, and robotic control and fabrication.

Common lab infrastructure will be built to help researchers working in each of these areas to collaborate, and one of the project’s main goals is to build a full-scale digitally constructed habitation module by the end of the 4-year initial investment period. Says Kohler: “New architecture and construction technologies can be tested at Nest, EMPA’s new building laboratory. We will build a residential unit there, thus demonstrating the synthesis of our approach. Over recent years at ETH, we have seen clearly that we learn most effectively by ‘making’ – real physical implementation at full scale.”

Additional funds will also go towards supporting and training the next generation of architects through the creation of a new, one-year postgraduate Master program in Digital Fabrication at ETH Zurich, the expansion of ETH’s Institute of Technology in Architecture current doctoral-level ‘Architecture & Technology’ program, the creation of various exchange and partnership programs with other universities and with industry, and the funding and support of patent applications, licensing and spin-off companies.

If you liked this article, you may also be interested in:

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

2022 update: A new, one-wheeled version of the Cubli has been developed. The one-wheel Cubli is a three-dimensional pendulum system that can balance on its pivot using a single reaction wheel, as it is shown in this article.

2014 update: My colleagues at the Institute for Dynamic Systems and Control at ETH Zurich have created a small robotic cube that can autonomously jump up and balance on any one of its corners .

This latest version of the Cubli (2014) can jumping up, balance, and even “walk”. This new version is self contained with respect to power and uses three slightly modified bicycle brakes instead of the metal barriers used in the previous version. We are currently developing learning algorithms that allow the Cubli to automatically learn and adjust the necessary parameters if a jump fails due to the deterioration of the brakes and changes in inertia, weight, or slope of the surface.

This robot started with a simple idea:

Can we build a 15cm sided cube that can jump up, balance on its corner, and walk across our desk using off-the-shelf motors, batteries, and electronic components?

There are multiple ways to keep a cube in its balance, but jumping up requires a sudden release of energy. Intuitively momentum wheels seemed like a good idea to store enough energy while still keeping the cube compact and self-contained.

Furthermore, the same momentum wheels can be used to implement a reaction-torque based control algorithm for balancing by exploiting the reaction torques on the cube’s body when the wheels are accelerated or decelerated.

Can this work?

The first step in creating the robot, therefore, was to look at the physics to figure out if a jump-up based on momentum wheels was possible. The image below shows some of the math to figure out the Moment of Inertia (MOI) of the wheel and full cube.

This mathematical analysis allowed a quantitative understanding of the system which allowed to inform design choices, such as the trade offs of using three momentum wheels vs. a design with a momentum wheel mounted on each of the six inner faces of the cube.

Another outcome of this analysis was a good understanding of the required velocities of the momentum wheel to allow the cube to jump up, and the torques required to keep the cube in balance. Both factors were critical for the next steps: Determining the required hardware specs.

Specs and hardware design
Given the required velocities and torques determined above, it was clear that the momentum wheel’s motor and gearbox would be a major challenge for creating the robot. Using the mathematical model allowed to systematically tackle this problem by allowing a quantitative analysis of the trade-offs between higher velocities (i.e., more energy for jump-up) and higher torques (i.e., better stability when balancing).

This mathematics-driven hardware design resulted in detailed specs for the robot’s core hardware components (momentum wheels, motors, gears, and batteries) and allowed a CAD design of the entire system.

Part of this step was the design of a special brake to suddenly stop a momentum wheel to transfer its energy to the entire cube and cause it to jump up.

The photo to the left shows an early design of this brake, consisting of a screw mounted on the momentum wheel, a servo motor (shown in black) to move a metal plate (in blue) into the screw’s path (in light brown), and a mounting bracket (in light brown) to transfer the momentum wheel’s energy to the cube structure. The current design uses a combination of hardened metal parts and rubber to reduce peak forces.

2D prototype
To validate the mechanics and electronics of the jump-up and balancing strategy and prove feasibility of the overall concept a one-dimensional version was built:

The results obtained with this 2D version of the cube were published in an IROS 2012 paper.

The final robot
Following successful tests with the 2D version, a full robot was built. The result is Cubli, a small cube-shaped robot, named after the Swiss-German diminutive for “cube”.

As you can see in the video, Cubli can balance robustly.

However, first jump-up tests showed that the stress resulting from a sudden braking of the momentum wheel led to mechanical deformations of the momentum wheels and aluminium frame. This made repeated jump-ups of the whole Cubli impossible without part replacement. It was therefore decided to tweak the structure and breaking mechanism to reduce the mechanical stress caused by the jump-up.

In addition to balancing, my colleagues are now investigating the use of controlled manoeuvres of jumping up, balancing, and falling over to make the Cubli walk across a surface.

Note 1: This post is part of our Swiss Robots Series. If you’d like to submit a robot to this series, or to a series for another country, please get in touch at info[@]robohub.org.

Note 2: This work was done at the Institute for Dynamic Systems and Control, ETH Zurich, Switzerland and was funded in part by the Swiss National Science Foundation (SNSF), grant number 146717.

Note 3: If you have questions, post them below and we’ll post answers.

Some more photos:

Thanks Gajan!

If you liked this article, you may also be interested in:

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

The team at the ETH Flying Machine Arena has released three new videos, demonstrating quadrotors building tensile structures, tossing a ball back and forth, and refining a figure-eight trajectory using iterative learning. Worth the watch!!

Building Tensile Structures with Flying Machines

Federico Augugliaro: “This video shows quadrocopters assembling prototypical tensile structures. Part of a body of research in aerial construction – a field that addresses the construction of structures with the aid of flying machines – the video demonstrates that flying machines are capable of autonomously spanning a rope between two support points. They can also create surface structures by using already placed ropes as new support points. Furthermore, multiple machines can work together to extend the type of structures that can be created by this means. The project is a collaboration between the Institute for Dynamic Systems and Control and the Professorship for Architecture and Digital Fabrication, both from ETH Zurich, Switzerland.”

See Federico’s research paper, a collaboration with Ammar Mirjan, presented at the IEEE/RSJ International Conference on Intelligent Robots and Systems 2013.

Rapid Trajectory Generation for Quadrotors

Mark Mueller: “We have developed a method for rapidly generating and evaluating quadrocopter interception trajectories. Each trajectory goes from an arbitrary initial state (position, velocity and acceleration) to an arbitrary final state. The evaluation of the trajectory includes determining input feasibility, and state feasibility (e.g. that the position of the quadrocopter remains inside a box). Per trajectory, this requires less than two microseconds on a modern laptop computer.

The trajectory generator is used here to generate trajectories to hit a ball towards a target, and determines:

•  when to hit the ball
•  how high to return the ball
•  how much thrust to use at the end of the trajectory.

The trajectory generator is used in a receding horizon implementation, where the optimization is run in closed loop at 50Hz, and only the first part of the trajectory is used as inputs. This allows the system to cope with sensor noise, and deviations in the ball’s flight path.”

See Mark’s research paper, presented at the IEEE/RSJ International Conference on Intelligent Robots and Systems 2013.

Iterative Learning for Periodic Quadrocopter Maneuvers

Markus Hehn: “This video demonstrates an iterative learning algorithm that allows accurate trajectory tracking for quadrocopters executing periodic maneuvers.

The algorithm uses measurements from past executions in order to find corrections that lead to better tracking performance. In order to do this, we measure the tracking error over two laps of the maneuver. The new correction is then computed and applied. After waiting for one lap, we begin measuring again and the next learning step follows. For particularly dynamic maneuvers, we begin the learning process at lower execution speeds. This allows us to initially improve performance under safer conditions, and the algorithm provides a means to then transfer the learned corrections from the lower execution speed to higher speeds. The experience gained at lower speeds thus helps us when flying at high speeds, similar to how people learn skills such as martial arts or playing the piano. The method is also applicable to more complex tasks, shown here by the example of the quadrocopter balancing a pole while following a trajectory.”

See Markus’ research paper, presented at the IEEE/RSJ International Conference on Intelligent Robots and Systems 2013.

A team of students from ETH Zurich and ZHdK have developed a prototype for a robotic ship inspection unit that is capable of conducting visual inspections of ship ballasts. Ballast inspection – which involves navigating hard-to-reach spots with no line of sight, often in the presence of intense heat, humidity, and hazardous gases – is normally done by human inspectors, and represents a significant cost to ship-owners who must pay for dry-docking and who face lost income when they cannot operate their ships during the inspection period. Because robotic ship inspection can occur while the ship is in operation, it could significantly reduce dry-dock time. The Ship Inspection Robot (SIR), which was developed in conjunction with Alstom Inspection Robotics and which uses magnetic wheels to navigate the I-beams and other awkward obstacles found inside ship ballast, is relatively compact and does not require any cables for power or communication, and thus offers significant mobility improvements over other robotic ship inspection prototypes. Project leaders anticipate that a per unit production cost could be as low as €4K, enabling shipping companies to operate several units in parallel as an additional time-saving measure. The robot was developed as part of a Bachelor-level project that aims to give students practical experience and promote contacts with industry.

Cargo ships, which transport everything from bananas, coffee, grain, coal, heavy equipment, chemicals, oil and gas, are the backbone of intercontinental trade, and the shipping industry represents an annual estimated average of more than €300bn worldwide. According to the International Shipping – Facts and Figures report published by the International Maritime Organisation, there were 103 392 commercial ships in service by January 2011. With an average age of 19 years and an expected lifespan of 25 years, regular inspection and repair is an important part of the global fleet maintenance.

The mechanical stress of loading and unloading, and the corrosive properties of seawater all take their toll on a vessel’s structure. This is especially true for a ship’s ballast tanks, which are filled with seawater to compensate for weight changes as cargo is loaded and unloaded. Located between the outer hull and the cargo holds, and consisting of beams and stiffeners separated by bulkheads, ballast tanks form much of a ship’s supporting structure.

The surface of ballast tanks is subject to saltwater exposure and algae accumulation, and as a result, must be inspected for damage every five years. A standard visual inspection, which can only be conducted with the ship in dry-dock after about a two-day venting period, serves as a kind of triage for determining what repairs are needed, and where. During inspection and repair, time is of the essence. Ship owners must pay for every day in dry-dock (€16K to €25K per day) and, in addition, they face loss of income when goods cannot be transported (€16K – €50K or more per day, depending on the value of the goods; oil and its derivatives, for example, can double in value within weeks in the event of a oil crisis).

Visual inspection is normally carried out by humans; however, intense heat and humidity, and hazardous gases make ship inspection a difficult and dangerous task. Ballast inspection is therefore an ideal task for robots, but the inside of the ballast, which has both convex and concave edges, as well as T-, L-, bulb- and I-profiles, presents a significant navigation challenge for any robotic inspection system. A few prototypes have been developed to date, however most of these systems have been large and heavy, and have required cables (for communication and power) that significantly limit their range and mobility.

The project
SIR was developed as part of an industrial-academic collaboration between Alstom Inspection Robotics, ETH Zurich and ZHdK. Alstom Inspection Robotics proposed a project that would result in a lightweight, low-cost robot for inspecting ships and similar structures, and provided some of the technology; a team of ten undergraduate students (six mechanical engineers and two electrical engineers from ETH Zurich, and two industrial designers from ZHdK) completed the project from concept to functional prototype as part of a nine-month bachelor-level focus project.

Developing the inspection scenario

In order to research the state-of-the-art of the ship inspection process, we went to a shipyard in Rotterdam to interview ship owners, inspectors, and maintenance workers, and to explore the inside of bulk carriers — SIR’s eventual workplace. This visit helped us to understand everyone’s priorities, how an inspection robot might be used to address them, and allowed us to develop, together with Alstom Inspection Robotics, a realistic potential inspection scenario that would serve as a guide for SIR’s eventual design. Here is the scenario we came up with:

As part of a round-the-year continuous inspection, the ship owner decides to use a four-day cruise to inspect part of the ballast tank. The inspection area is split into sections 3m wide and 50m long, which are bordered by stiffeners that can be climbed, but which limit sight. Calculations done on power consumption suggest a run time of about three hours; with an assumed average speed of 4.5 cm/s (calculated as a weighted mix of maximum and obstacle speed), ten of these sections could be inspected on a single battery charge.

Once inspection is complete, the data is analysed and suspicious areas are marked. Available data from earlier inspections is used to detect changes, and the damage map is updated. The next time a ship is due for inspection, the damage map is checked, and necessary equipment and material are ordered before the ship even enters the dry dock. 

Once in dry dock, the ship is vented and known repairs begin without delay at the same time as small or complexly shaped areas (like the bow) are manually inspected. A full inspection is shifted to the end of the dry-docking: since the inspectors already have access to the data, they can identify critical problems in advance and shorten the time they spend inspecting undamaged areas.

The prototype

The focus project resulted in a prototype for a relatively small, cable-less robotic ship inspection system that we call the Ship Inspection Robot (SIR). The prototype uses magnetic wheels to crawl along the metal ballast surface; SIR is controlled by a human inspector via wireless transmitter, and a powerful battery allows for approximately three hours of run time on a single charge. We envision that future prototypes will be able to map damaged areas. Below are some of SIR’s most important features:

1. Continuous inspection for early damage detection
   Because, unlike its human counterparts, SIR is immune to poor air quality and does not require scaffolding to climb, inspection could be undertaken while the ship is cruising. It could thus be used as part of an on-going year-round inspection program, allowing ship owners to identify and monitor suspicious areas, and order materials and plan repairs ahead of a scheduled dry-docking. While SIR is not meant as a replacement for a human visual inspection, it would allow human inspectors in dry-dock to focus on damaged areas, and on areas that are not accessible by robot, such as the ship’s bow.
2. Low cost of entry
   Because of its structural simplicity and its use of relatively inexpensive peripheral equipment, the target per-unit production cost of a commercially produced version of SIR is expected to be about €4K, allowing ship-owners or their subcontractors to treat them as a consumable rather than an asset. This low cost would allow operators to own and operate several units in parallel. The prototype cost about €12K to produce.
3. Low degree of autonomy
   Conceptually, SIR has a low degree of autonomy. Ship inspections are carried out according to very strict regulations and procedures, leaving no margin for errors, and one way to reduce errors is to keep things simple. This feel of being ‘in control’ also increases market acceptability.

How it works

SIR features four overlapping magnetic wheels, which allow the unit to maintain continual contact with the ship’s surface, even as it navigates sharp angles, vertical surfaces and overhangs. A gamepad allows the human operator to control the device, and a top-mounted camera and lighting system allow for visual inspection. The robot has almost no on-board computing power, making it lightweight and power efficient; almost all processing and control tasks (with the exception of a micro-controller for bundling sensor data) are executed on a base station that runs the Robot Operating System.

The robot uses four Sharp infra-red distance sensors for edge and obstacle detection, and an Invensense MPU 6050 IMU provides the operator with orientation data. These sensors are currently only used for user feedback. The camera used on the robot is a GoPro Hero 3 where it serves as a demonstrator for a visual sensor. It is assisted by three lights, one pointing in the viewing direction while the other two illuminate the ground in a flat angle, so as to make bumps and small edges more visible thanks to the longer shadow they cast on the ground.

Communication is carried out by two systems. The first system is an analogue wireless device. It uses the same 2.4GHz frequency as normal WLAN devices, however the signal is analogue, giving it more stability. It can be exchanged for an ethernet cable at any time. This device is used to control the robot, since delay through this channel is barely perceivable. The second system is a wireless video transmitter for the GoPro camera that is often used in model airplanes.

Performance
Working as part of an interdisciplinary team and organising a project all at once was certainly a challenge, however SIR proved itself to be a successful focus project. Not only did SIR perform as planned, it also showed that the mechanical and electrical design can be integrated into a robust and compact design; this was achieved by working closely together to integrate our various areas of expertise.

Our primary goal was for SIR to be able to overcome obstacles, and thanks to its compact wheelbase, SIR is able to do this with a high reliability, a thing no other robot known to us can do! Overcoming obstacles still needs some work in terms of reliability and smoothness, however, the robot never detached from the surface during a test and, in most cases, was recoverable without interaction from outside. We are proud that we were able to raise the bar in this respect.

So far, tests have shown that many of the other desired tasks can also be fulfilled by the current prototype, such as the ability to carry a variety of sensors.

SIR’s high range of mobility is the key value we added to the state-of-the-art of inspection robots, and thus the biggest achievement of our project. The ability to climb all these additional obstacles is not only beneficial for ship inspection, but also useful for many other robot applications such as power plant inspections.

Further development of SIR lies in Alstom Inspection Robotics’ hands.

Links
SIR website
Product Development Group at ETH Zurich
Alstom Inspection Robotics
ZHdK

If you liked this article, you may also be interested in:

• Ship hull cleaning & inspection – ideal for robots
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• Underwater ROV keeps its eye on the target

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

Such multi-UAV systems were in the focus of the Sixth Lakeside Research Days organized and hosted by Lakeside Labs and the University of Klagenfurt in Klagenfurt, Austria, from July 8 to 12, 2013.

Concept and Program

The Research Days are a special format of workshop. Besides keynote talks given by invited experts from academia and industry, they feature a demonstration session, intensive group work, discussions on technological and business aspects, and social activities for attendees.

The keynotes were as follows:

• Small flying robots: Design and visual navigation
  By Roland Siegwart (ETH Zürich)
• Fusion of distributed perception in collaborative visual-SLAM approaches on mini-UAVs
  By Darius Burschka (TU München)
• Exploiting redundancy for reliable aerial computer vision
  By Horst Bischof (TU Graz)
• Aerial imaging and wireless communications with multiple autonomous UAVs
  By Christian Bettstetter and Evsen Yanmaz (U Klagenfurt and Lakeside Labs)
• Decisional issues in multi-UAV systems
  By Simon Lacroix (LAAS/CNRS)
• Slalom racing and flight dances: motion planning, control and learning for high-performance quadrocopter flight
  By Angela Schöllig (U Toronto)
• Multi-spectral people detection from UAVs
  By Stephen Cameron (Oxford)

A panel with Roland Siegwart, Hermann Hellwagner (Klagenfurt), Phil Charlesworth (EADS), and Michaël Rischmüller (Parrot) discussed business opportunities and start-up ideas of UAV systems.

Further information can be found in the final program and the Twitter feed #resdays13.

Media Coverage

The event was covered by various media including Austrian television ORF and the newspaper Der Standard (article Drones in peace missions).

Cover of “Der Standard” from 17 July, 2013

Impressions of the First Day

Keynote by Siegwart: Small flying robots

Keynote by Schöllig: Slalom racing and flight dancing

Image Gallery

Photos by Christian Philipp (Lakeside Labs GmbH) and Christian Bettstetter.

For many people, the term “innovation” implies having a great idea, and hoping that somehow it will take off. According to H. Chesbrough, this is clearly insufficient, and in his definition, he is very specific and demanding: an innovation is an invention that has been developed into a novel product or service, and which is creating economic value. Or simply stated: Without market success, no innovation has happened!

The importance of innovation and startups for a country’s economy
As most companies know from painful experience, the market success of novel products or services is not a given. According to Chesbrough’s definition, innovation therefore implies a high risk of failure. These risks tend to remain small as long as the innovation process is proceeding in incremental steps. Such “sustaining innovation” is the realm of established companies, which excel at deriving large value from small changes. However, if a completely new and different value proposition suddenly appears in a so-called “disruptive innovation”, established companies are frequently ill positioned to exploit the arising opportunities.

According to C. Christensen, established companies are then faced with the “innovator’s dilemma”: their existing customer base and company expertise are too far removed from the requirements of disruptive innovations. This really is the realm of startup companies and innovative SMEs because they are less risk-averse, more flexible and less mired by entrenched company traditions than well-established, already successful firms.

In effect, startups have also a major function as job creators in a country’s economy. As shown in an influential study by the Kauffman foundation, startup companies in the United States reliably create many more jobs than existing companies, and they do not show the economic fluctuations (net job destruction during recession periods) of existing firms. As a consequence, it is a major task of society and its universities to encourage and to support the creation of startup companies, in particular in the high-tech domain.

Fostering entrepreneurship at a university
What should a university do to foster entrepreneurship, beyond providing a solid technical education to its students? Finding and implementing good answers to this fundamental question is of particular importance to ETH, which is the number one university in continental Europe, according to several global university rankings. Since ETH aims to have maximum practical impact with minimum effort, the obvious thing was done: Successful entrepreneurs who had built thriving enterprises out of fledgling ETH spinoffs were asked what measures would have helped their companies to grow faster, hire more personnel and create more economic value. Without aiming for scientific rigor in our informal query, we were surprised to learn that successful ETH entrepreneurs consistently mentioned three key support measures making a large difference for a young entrepreneur:

1. Peer home:  Young scientists usually feel very much at home at their university institute, where every scientific or technical question is immediately answered efficiently and exhaustively. However, as soon as entrepreneurial issues are raised, the interest of other young scientists quickly vanes. As a consequence, young scientists with entrepreneurial ambitions are looking for a second, entrepreneurial home at their university, where they can find like-minded young talents. However, it is not only peer support that they expect to find in such a “biotope” but also peer stimulation and peer pressure: it is well-known that the most effective way for people to learn is from good (and bad) practical examples given by one’s peers.
2. Experienced coaches: It takes many years to become an experienced business person, to master the countless things it takes to build successful enterprises, and to develop a deep understanding of specific markets. For this reason, young talent can profit enormously from the practical advice offered by an experienced and successful serial entrepreneur. One should not underestimate the ability of a well-chosen coach to be a compelling role model, who passes on significant behavioral and ethical values in addition to technical and business know-how! For this reason, it is vital that the “chemistry” between coach and coachee is perfect, and a substantial effort should go into good matchmaking.
3. Network facilitation: The combined professional network available at an excellent university is enormous. Unfortunately, young entrepreneurs usually find it quite difficult to tap into this huge network – either because they do not know whom to ask, or what and how to ask. As a consequence, young entrepreneurs need “network facilitators” who have both the experience and the authority to make a university’s vast network available to the young talents with high effectiveness.

The ETH Innovation and Entrepreneurship Lab (ieLab)

The desired “innovation biotope” for the ieLab was realized as several large open offices with associated infrastructure, where young talents can find a second, entrepreneurial home at ETH. We found that the different business cultures in various fields necessitated the creation of different ieLab open offices: one for typical engineering activities (including a mechanical work-shop), comprising robotics, automation, micro/nano-electronics or photonic microsystems; another one for life sciences (including well-equipped biochemical wet-labs), where development cycles are usually much longer and a trade sale exit to a large pharma/chemical company is rather the norm than the exception; another one for ICT startups with their characteristic very short time to market.  Each ieLab typically hosts eight to twelve teams.

The ieLab coaches are experienced and successful serial entrepreneurs, hand-picked from ETH’s vast network to match the personality of the young talents. The coaches share their large experience, business practices, market intelligence, supply chains, customer bases, investor communities etc. with their coachees, introducing them very effectively to all aspects of today’s high-tech entrepreneurship.

In particular, coaches have a deep knowledge of their respective markets – they know about the needs of potential customers and about the shortcomings of current solutions, and they are good at figuring out which novel technological solutions could have large market potential. Also, the coaches are instrumental in an often-overlooked aspect of the development of a startup: it has been found that fledgling high-tech startups grow faster and create more economic value if they have entered into a strategic R&D alliance with an established industry partner. The experience and negotiation acumen of an adept coach can help enormously in the creation of a win-win alliance partnership between academic spinoff and large industrial company.

The ETH network facilitators are all very experienced in the startup process and they have a vast network at ETH and other leading universities. Since they have their desks right in the middle of the open spaces, there is no entry barrier for the young talents to ask for help and to watch how problems can be solved effectively.

In addition to operating the ieLab, ETH offers a range of support services for the fostering of entrepreneurship, most notably ETH transfer, the tech-transfer office of ETH. All questions regarding contracts, legal issues, intellectual property, licensing, etc. are answered by ETH transfer’s professional crew. Several types of events related to entrepreneurship are regularly organized, including the ieLab weekly lunch seminar, industry days, homecoming dinners for ETH spinoffs, the Spark Award, “meet the pioneers” events, partnership council meetings, etc. Finally, ETH offers Pioneer Fellowships to the most gifted 10-15 young entrepreneurs each year. This includes CHF 150,000 seed money, free incubation in one of the ieLabs, free access to the services of ETH transfer, as well as individualized free coaching and networking throughout the 18 months of the Fellowship.

Entrepreneurship in the ETH curriculum
At ETH, entrepreneurship is not a set of isolated activities; it is an integral part of the ETH culture. This is particularly evident in how the entrepreneurial spirit is fostered early on in a young researcher’s studies at ETH, with Focus Projects, for example. The students in several departments have the choice how they spend their last bachelor year: either in the conventional way with a full set of lectures, or in a focus team with fifteen to twenty like-minded students, usually from different departments. Only a reduced set of lectures must be taken – much of the time is devoted to a “grand challenge”, where the team often tries to break a world record. The students must solve all problems themselves, only lightly coached by experienced advisors. They must organize themselves, plan their project and monitor progress, find suitable sponsors for their project, control their own budget, communicate with other teams and the media, and work extremely hard towards a common goal: “Demo or die” on rollout day, when they either demonstrate that they have jointly stood up to their challenge, or that they have failed together…

This experience makes great team players out of initially individualistic students; they have learned how to acquire additional theoretical knowledge effectively and how to apply it rapidly to their practical problems, they have become flexible problem solvers, and – last but not least – they realize their entrepreneurial potential.

A case in point – Robotics innovation “Skye”
A good example of how innovation and entrepreneurship have become deeply ingrained into the ETH culture is the robotics innovation Skye. It all started with a difficult challenge to be tackled in the framework of an ETH focus project. The problem was to come up with a robotic solution for the safe monitoring of large crowds or complex technical facilities, making sure that no dangerous situation could arise due to the possible malfunction of a component or sub-system.

The challenge was embraced by a dedicated team of nineteen students from diverse ETH domains such as robotics, mechanical engineering and electronics, as well as industrial design students from the Zurich University of the Arts. The students came up with a novel concept of a surveillance robot: an omnidirectional spherical blimp capable of travelling at speeds of up to 20 km/h and at cruising altitudes up to 500 m above ground. Thanks to its helium-filled hull, the Skye can stay airborne for longer than an hour; the four main steerable electrical motors on the 2.6 diameter blimp are merely used for movement and stabilization against wind forces. The Skye project was supported financially and received expert advise from Disney Research Zurich, the ETH Autonomous Systems Lab, the Linde Group (PanGas), Maxon Motors, and several other Swiss companies.

As a consequence of their successful focus project, and thanks to encouraging feedback received from potential users of their innovation, a half-dozen members of the original Skye team decided that Skye could become a business – and that they could become successful businessmen!

Today, the core Skye team is following up on this challenge to create economic value out of their research project, and they are supported in this quest by the ETH ieLab. The Skye team members are maturing their entrepreneurial skills, they are improving the original concept, and they are applying it to practical problems. Their goal is for Skye to become the most safe and energy-efficient solution for demanding surveillance applications such as monitoring large crowds, complex technical installations, high-rise buildings, agricultural crops or geological/archeological sites.

The experience of the Skye team is similar to that of other young researchers at the ieLab: entrepreneurship is not just about learning management techniques and tools – it is about undertaking challenging tasks and accomplishing astonishing things!

References:

H. Chesbrough, “Open Innovation – The New Imperative for Creating and Profiting from Technology”, Harvard Business School Press, Boston (MA), 2003.

C. M. Christensen, “The Innovator’s Dilemma”, Harper Business Essentials, NewYork, 2000.

T. Kane , “The Importance of Startups in Job Creation and Job Destruction”, Kauffman Foundation Research Series: Firm Formation and Economic Growth, Ewing Marion Kauffman Foundation, July 2010.

R. B. Cialdini, “Influence – The Psychology of Persuasion”, HarperCollins Business Essentials, New York, 2007.

S. Hess, “An Open Innovation Technology Transfer Concept – R&D Cooperation for Breakthrough Technologies Between Academic Spin-Offs and Established Industry”, Dissertation ETH No. 20731, 2012.

Examples of ETH focus projects are described at http://www.asl.ethz.ch/research/focus

Skye project website: http://www.projectskye.ch

Unlike larger robots, microrobots for applications in the body are too small to carry batteries and motors. To address this challenge, we power and control robots made of magnetic materials using external magnetic fields. Developed at ETH Zurich’s  Multi-Scale Robotics Lab (MSRL), the OctoMag is a magnetic manipulation system that uses electromagnetic coils to wirelessly guide microrobots for ophthalmic surgery. 

The OctoMag is capable of generating magnetic forces and torques in three dimensions, and is physically restricted to a single hemisphere to allow easy access for patients and physicians. Using an early OctoMag prototype, ex-vivo experiments were performed in pig eyes to study the navigation tasks required for retinal surgery. Following these experiments, a next-generation system was built to accomodate a small animal head, allowing for in-vivo trials. With this system, mobility experiments were conducted in which a microrobot with a diameter of 285 µm (about four times the width of a hair) was navigated reliably through the eye of a rabbit, demonstrating the feasibility of using this technology in surgical applications.

Robots are capable of exploring many environments that are difficult, if not impossible, for humans to reach; the edges of the solar system, the planet Mars, the inner depths of volcanoes, and bottom of the ocean are just some examples. The goal of these robotic explorers is to obtain knowledge about our universe and to answer fundamental questions about the nature of life on Earth. Recently, micro- and nanotechnologies have fueled an exciting expansion of this field by allowing scientists to use robots to probe life at much smaller scales. Nanorobotic systems for exploring the structures of biological cells, and robotic motion planning strategies for the investigation of protein folding, are two compelling examples of the intermarriage between robotics and nanotechnology. Such efforts and others like them illustrate how several areas of science and engineering are rapidly converging to create a new, interdisciplinary approach to research that promises to revolutionize our understanding of the world around us.

While many envision a future in which intelligent nanorobots navigate throughout our bodies searching for and destroying disease, researchers are still far from realizing such advanced technologies.  However, progress is being made, and the past decade has seen impressive advances in the fabrication, control, and delivery of power to tiny motile devices.

The MiniMag is a research tool for studies at the micro scale. As a scaled-down version of the OctoMag, the MiniMag can be integrated into an upright or inverted microscope. The eight electromagnetic coils are slightly tilted and can be positioned very close to each other due to their smaller size, and, by reducing the magnetic workspace to one cubic centimetre, much higher forces can now be achieved. Combined with high-resolution optics, the MiniMag system allows for single cell manipulation and studies at the tissue level in 3D.

From the microscale to the nanoscale
As size decreases to the nanoscale, wireless magnetic manipulation becomes increasingly challenging. The magnetic force drops by a power of three as it scales with volume, and fluidic drag forces begin to dominate as inertial forces become negligible. While a number of robotic swimming methods have been proposed to aid mobility at relatively small scales, many of these methods rely on reciprocating motions and do not scale downwards.

More than three billion years ago, bacteria evolved a swimming strategy at micrometer dimensions that nature has had difficulty improving upon, and in 1973, H.C. Berg and R.A. Anderson first described a swimming technique that uses rotating helical flagella. Inspired by this work and the flagellar motion of bacteria such as Escherichia Coli, we have recently developed artificial bacterial flagella (ABF). Our ABF represents the first demonstration of wireless swimming microrobots similar in size and geometry to natural bacterial flagella, and are many orders of magnitude smaller than existing artificial helical swimmers. With the help of 3D-laser-nanolithography, arrays of thousands of such swimmers can now be fabricated. A careful choice of materials allows for cellular interaction, and fluorescent labeling of the device assists with localization and tracking. We are pursuing applications such as the treatment of breast cancer and cerebral infarctions.

The potential impact of this technology on society is high, particularly for biomedical applications, though many challenges remain in developing micro and nanorobots that will be useful to society. An overarching requirement for achieving breakthroughs in this area is the need to bring together expertise from a wide variety of science and engineering disciplines.  Robotics brings expertise in the planning and control of mechanisms with many degrees of freedom in uncertain environments. Nanotechnology teaches innovative approaches to fabricating nanoscale machines. In addition, biomedical imaging advances are needed, as is fundamental insight into the nature of fluid dynamics at very small scales.  Medical professionals must be tightly integrated into the development cycle, and experts in developing business models and intellectual property must be closely consulted.

About the researchers
Brad Nelson’s Multi-Scale Robotics Lab (MSRL) at the Institute of Robotics and Intelligent Systems, ETH Zurich, Switzerland, is a highly multi-disciplinary research group that leverages advanced robotics techniques to create intelligent machines that operate at micro- and nanometer scales.  At the MSRL, a team of nearly 30 scientists pursues a dynamic, robotics-oriented research program involving several emerging areas of science and technology.  The technical backgrounds of the scientists in the lab span such diverse fields as materials science, physics, biology, electrical and mechanical engineering, and computer science.

The materials scientists in the lab focus mainly on developing the tools and processes required to fabricate and assemble microscale robots and nanoscale robotic components.  Many of these systems are then used in the study of biological environments, including the investigation of molecular structures, cellular systems, and organism behavior.  Other members of the MSRL research team are focused on the design and implementation of systems that wirelessly control these microrobots.  Potential applications are numerous and diverse, including microrobotically-assisted surgery, magnetic micromanipulation at the cellular level, low Reynolds number locomotion, wireless power delivery, electrostimulation of biological materials, and micro- and nanostructure fabrication and characterization.

The MSRL develops systems for controlling micro- and nanorobots in liquid and pursues various applications for these devices.

[Edited by Hallie Siegel]

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See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

“The whole is greater than the sum of its parts” — a catch phrase that aptly expresses the Distributed Flight Array: a modular robot consisting of hexagonal-shaped single-rotor units that can take on just about any shape or form. Although each unit is capable of generating enough thrust to lift itself off the ground, on its own it is incapable of flight much like a helicopter cannot fly without its tail rotor. However, when joined together, these units evolve into a sophisticated multi-rotor system capable of coordinated flight and much more.

In the beginning
In the summer of 2008, Professor Raffaello D’Andrea at the Institute for Dynamic Systems and Control at ETH Zurich envisioned an art installation consisting of single-rotor robotic units that would self-assemble on the ground and then perform a joint task that would otherwise be impossible to achieve on its own — flight. This modular flying vehicle would then break apart in the air and then repeat the process over again, but in a new randomly-generated configuration.

Feasibility study
The number of challenges faced in designing and implementing such a system are many. We first wanted to be sure, however, that the concept was indeed feasible. Making some realistic assumptions about the system we performed some back-of-the-envelope calculations and created a linear dynamics model of the vehicle in order to provide us with some intuition about its physical dynamics. From this, a control strategy was devised. We then simulated the closed-loop system under a variety of disturbances, providing us with a general understanding of the physical requirements needed to successfully execute the project.

Design and implementation of the physical system began in the fall of 2008 as part of a design project class at ETH Zurich. The class consisted of eight graduate-level students from mechanical, electrical, and software engineering, as well as technical staff and instructors, including myself. Our task was to design and build a functional prototype that would demonstrate three key abilities of the system: (1) docking, (2) coordinated ground mobility, and (3) coordinated flight. In accomplishing each of these tasks, we would in turn validate our model and control strategy, and likely discover limitations to the system we did not foresee.

The project was no doubt challenging, and the timing constraints imposed by the class did not work in our favour. Our initial hope was to demonstrate each of the key abilities using a single set of vehicles and to demonstrate coordinated flight in several configurations. Our goals were too ambitious under the framework of this class and therefore loosened our requirements. By the summer of 2009 (a few months after the class had ended), we succeeded in demonstrating each of these key abilities, and ultimately, the project’s feasibility.

Towards the end of the above video, you will notice one of the many limitations of the system: its inability to control its altitude (or height off the ground). You may also notice that both flying and driving capabilities were separated in order to make the vehicle lighter for flight. Its primary limitation, however, was its inability to demonstrate coordinated mobility for randomly assembled configurations. The units themselves lacked the ability to communicate on each of their sides, and even if this were possible, we did not yet have any way of automatically generating the appropriate control strategy for the assembled configuration. For our demonstration, each unit was pre-programmed for a particular configuration and the controller was tuned by hand. This, however, was just the tip of the iceberg for the long list of requirements needed to successfully achieve our final goal.

Design iterations
With the design project class under wraps, and feasibility of the system demonstrated, the next step was to engineer a truly modular system capable of coordinated mobility — both on the ground and in the air. This was by no means a straightforward process; if it was, it wouldn’t be considered research. One additional revision of the vehicle was created prior to arriving at the current design.

In designing Revision 1, one of our major goals was to integrate both driving and flying capabilities. This required us to rethink the mechanical chassis and to design with a sufficient thrust to weight ratio in mind. Although light-weight and mechanically robust, the ethyl polypropylene foam chassis we used in the proof-of-concept vehicle was difficult to manufacture and our experience led us to switch to a different material. We opted instead for constructing the chassis out of laser-cut acetal plastic, a higher-powered flight motor, and a new propeller. This resulted in a very robust chassis, which was easy to fabricate in-house, and it provided sufficient thrust for the purposes of lift and control effort. What we failed to consider, however, was the stiffness of the chassis and manufacturing variability of the rotors. Only after completing the design of Revision 1 and producing several units did we discover that the vibrating modes in the chassis caused by aerodynamic turbulence from the propellers saturated the onboard rate-gyroscope sensors, which was needed for closed-loop control.

It was also important in this revision to demonstrate communication on each of its six sides. We successfully accomplished this using infrared transceivers mounted to each connection interface. However, we later discovered interference issues when conducting experiments with our vehicle within the environment of a 3D motion capture system (needed for ground truth measurements), which uses a similar frequency of infrared light to illuminate markers that it tracks in order to estimate the pose for the object of interest.

On top of this was the need to shrink the size of the electronics such that it would fit within the protected volume of the chassis. We were motivated by recent manufacturing possibilities in creating flexible printed circuit boards, and locked on to this scheme. When it came around to producing the boards, however, the lead-time for such services in relatively small quantities was much too long for our requirements — we wanted to be able to prototype and have a quick turn-around on our designs. We therefore had to redo parts of the design for a standard printed circuit board.

There was also the suggestion to first fly the system using a 3D motion capture system for measurement feedback. Since these measurements were very precise and relatively fast, we could by-pass the onboard estimation problem and focus only on the control problem. This, in fact, worked against us for two major reasons: (1) as described before, the infrared light from the 3D motion capture system interfered with inter-communication; and (2) measurement information (or control information) needed to be transmitted to the vehicle wirelessly for control purposes, which at the time of development (using WiFi) generally incurred a lot of latency and packet loss.

There was a lot that needed to be redesigned, a lot that was assumed, and there was pressure to get research publications out. In Revision 1, we tried to jump over too many hurdles at once and what we delivered was a semi-functional system — functional under optimal operating conditions, but failed to work most of the time. However we learned many things, in particular it focused our attention on parts of the design that we overlooked. This laid the ground work for Revision 2.

In Revision 2, we redesigned the chassis and thrust generation unit (i.e. propeller and flight motor) from scratch, but kept most of the power and control electronics the same. Using some of the most recent advances in manufacturing technology, the chassis was 3D printed this time around, enabling us to design with very little fabrication constraints and has a relatively quick turn-around time. The first factor was very important because of the number of tightly integrated components held together within a single unit. The second factor enabled us to quickly test a design and re-iterate as necessary.

This time around, we stepped through each phase of the design systematically. The new flight motor and propeller was tested to ensure that it produced a sufficient amount of thrust and produced little vibration within the chassis, which we tested using the rate-gyroscope sensors from Revision 1. Using two units and electronics from Revision 1, we tested the closed-loop behaviour around a single axis of rotation by mounting the two units on a horizontal pivot. This alone required a few iterations of the chassis, which in the end we managed to get right.

Ignoring the intercommunication problem, we ploughed ahead and constructed six complete units for flight. In this revision, we demonstrated coordinated flight for a variety of configurations. The flight controller was computed ahead of time and sent wirelessly to each unit prior to flight.

Knowing that the chassis and thrust generation unit was sound, we then went ahead and integrated driving capabilities and intercommunication into the units. In terms of the latter, we redesigned the intercommunication scheme, employing a hard-wired interface instead of an infrared wireless link and utilized an electrical bus to clean up the mess of communication lines we had in Revision 1. A detailed description is given in the next section.

Designed from the ground up
Each unit uses a single 32-bit 72 MHz microcontroller to interface with all of the onboard sensors, actuators, and communication peripherals. The same microcontroller is also used for performing all of the computation necessary for estimation and control — there is no computation that is performed offboard. An interchangeable wireless module (either WiFi or proprietary frequency hopping spread spectrum) allows us to communicate with each unit (e.g. telemetry and user commands); in the case where external sensors are used (e.g. 3D motion capture system), the data can be sent to the units over this wireless link.

Standard on most aerial vehicles is a 3-axis rate-gyroscope, which is used for measuring body angular velocities, as well as estimating the attitude of the vehicle in flight. An infrared distance measurement sensor is used for measuring the distance of a unit to the ground. Not only is this used for estimating the altitude of the vehicle, but if units share their distance measurements with one another they can also estimate the vehicle’s tilt when flying over a flat surface.

We have designed each unit with magnetic interfaces, located along each of its six sides. This allows a unit to passively self-align with its connected peers. The connection strength, however, is in fact not very strong. This was intentional, as it clearly demonstrates the need for cooperation between individual units in order to achieve flight — without it, the vehicle would simple rip itself apart before take-off. To successfully accomplish this, the flight control strategy must minimize the shear forces occuring between interconnected units during flight.

Also located on each of its six sides are three gold push-pins. Together with the magnets, this interface behaves similarly to the Apple MagSafe power connector, except that this interface is used to provide a means for hard-wire communication between neighbouring peers. With this, we developed our own network layer to handle inter-unit communication, as well as algorithms for routing packets, time synchronization, information fusion, etc. on a resource limited embedded system. Units are also able to communicate with one another in plane at a distance using infrared wireless transceivers, which is primarily employed for self-assembly purposes.

Each unit is equipped with three omni-directional wheels, allowing it to move on the ground with a high degree of maneuverability and to be able to move when assembled together. One of the nice things about using 3D printer technology is that the omni-wheels could be printed as a single piece, without having to assemble any components.

Positioned at its centre is a fixed-pitch propeller, capable of generating enough thrust to lift a single unit off the ground. All units are physically identical except for the handedness of its propeller. Some are clockwise and some are counterclockwise — this is needed in order to cancel out the aerodynamic torques in flight. Finally, a high energy-density Lithium-Ion Polymer battery is used to power all the electronics and actuators contained onboard.

Coordinated flight
The units can move around on the ground, self-assemble, generate an adhoc mesh network in order to communicate with one another, but the most striking feature of the Distributed Flight Array is its ability to fly in an unlimited number of configurations.

Recall that the units are being held weakly together with magnets. Thus, each unit is generating the appropriate control effort necessary to keep the vehicle in flight while minimizing the shear forces between individual units. What is most surprising is that the units themselves do not necessarily need to communicate with one another during flight.

The only information that a unit needs for flight is its local sensor data and its position with respect to the vehicle’s centre of mass. This can be computed if each unit knows the physical configuration of the vehicle. In order for a unit to determine this on its own, each unit can work out its relation to neighbouring units by sharing appropriate information. By forwarding this information around the network, each unit can arrive at the physical configuration of the vehicle, much like how one might establish his/her family tree.

Assuming a rigid body for the vehicle, which was taken into account when designing the chassis, local sensor information provides a unit with a rough estimate of the vehicle’s tilt and altitude. And knowing its position with respect to the centre of mass, it’s straightforward to work out the appropriate control effort needed to counter-act any disturbances. We avoided using a linear quadratic regulator or other optimal control strategies in favour of something much more straightforward, and as it turns out the method is also scalable. We employ a cascaded parameterized controller, consisting of tuning parameter that are physically intuitive (i.e. closed-loop natural frequency and damping ratio) for each degree of freedom.

Now, it wouldn’t be reasonable to hand-tune the controller for each and every configuration. We instead developed a means for automatically computing the tuning parameters for any flight-feasible configuration of the vehicle that would result in best flight performance. In carefullly analyzing the parameters obtained for a variety of configurations, we then developed a scalable method for mapping the configuration of a vehicle to its approximated optimal control tuning parameters.

Rewards and reality
A lot challenges, a lot of frustration, but also a lot of reward. What started as an idea is now a reality. Although we have not necessarily shown it to reenact the Concept Animation shown above, it is certainly capable of performing each of those tasks. What we have here is a piece that suitably demonstrates cooperative behaviour.

The success of this project would not have been made possible without support from the Swiss National Science Foundation, as well as the countless number of hours spent by students and technical staff — they all deserve as much credit. The Distributed Flight Array is currently being used at the Institute for Dynamic Systems and Control at ETH Zurich as a modular robotics platform for investigating algorithms in distributed estimation and control. Updates regarding the project’s status and a list of those involved with the project can be found on its home page.

Who’s Currently Involved: Raffaello D’Andrea, Maximilian Kriegleder, Igor Thommen, and Marc A. Corzillius

Photo credit: Raymond Oung

Note: This post is part of our Swiss Robots Series. If you’d like to submit a robot to this series, or to a series for another country, please get in touch at info[@]robohub.org.

If you liked this article, you may also be interested in:

• Insect-inspired flying robot handles collisions, goes where other robots can’t
• The Distributed Flight Array: Modular robots that self-assemble, coordinate and take flight
• Designed to mingle: Rezero ballbot’s smooth moves can handle a crowd
• Cubli – A cube that can jump up, balance, and walk across your desk

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

TED Global speaker/drone ecologist Lian Pin Koh and fellow researcher Serge Wich share how drones are playing an important role in helping conservationists survey and map ecologically sensitive parts of the globe.

Global land-use changes continue to be a major driver of biodiversity loss and greenhouse gas emissions. Remote sensing technology is increasingly used to assess changes in land use, species distributions and carbon stocks. However, satellite and airborne sensors can be prohibitively costly and inaccessible for researchers, or they may not have the required spatial resolution. Recently UAVs have been used by conservation researchers and practitioners across various parts of the world. These inexpensive UAVs typically cost less than $4000 US, and have been dubbed ‘Conservation Drones’. The drones are equipped with cameras to record videos at up to 1080 pixel resolution (high definition), and acquire aerial photographs of <2 cm pixel resolution. Aerial photographs can be stitched together to produce near real-time geo-referenced land use/cover maps of surveyed areas and 3D models.

This post is part of Robohub’s TED Global 2013 coverage.

Why did we develop Conservation Drones?
Globally, biodiversity continues to decline, and a disproportional amount of this decline occurs in the tropics where the majority of global biodiversity is found. One urgent challenge for conservationists is to be able to accurately assess and monitor changes in forest cover, species distributions and population dynamics. To obtain such data, conservationists currently rely on satellite-based remote sensing for mapping and monitoring land use changes, and on ground surveys to determine and monitor species distribution and population dynamics. Although low-resolution satellite images are freely available at specific time intervals, it is often prohibitively expensive to obtain sub-meter resolution images. Yet, such high-resolution data are often critical for accurately detecting and tracking land use change at the landscape scale. Furthermore, large portions of the humid tropics are often obscured from remote sensing satellites due to persistent cloud cover. As such, cloud-free satellite images for a specific time period/series and location are often not readily available.

A second major conservation challenge concerns assessment and monitoring of biodiversity. Currently, this is largely achieved through ground surveys, which are often time-consuming, financially expensive, and logistically challenging in remote areas. As a result, surveys are not conducted at the frequency required to monitor population trends, and some remote tropical forests have never been surveyed for biodiversity due to difficult and inaccessible terrain.

An additional challenge for conservationists is the illegal encroachment into protected areas and illegal hunting of prized animals, such as tiger, rhinos, and elephants. The areas that need to be surveyed in these cases are large, and current ground and manned aircraft surveys do not occur regularly enough to be able to effectively reduce illegal activities.

To address these challenges, we are developing the use of inexpensive, autonomous unmanned aerial vehicles for surveying and mapping forests, biodiversity and potential illegal activities – Conservation Drones.

What are Conservation Drones?
Although we have been using several airframes for our drones since we started, the core part of the system has remained the same. The core is an autopilot system (APM) developed by an online community (diydrones.com). By combining the APM with open-source mission planner software (APM Planner), we convert off-the-shelf model airplanes into drones. We use inexpensive airframes so that the technology can be accessible to conservation organizations and researchers, who often do not have the funding to acquire drones and maintain them.

The sensors
We have equipped our drones with various camera systems for still-photography and videography. We have been mainly using the Canon SX230 with a build-in GPS so that all photos are geo-tagged. We replace the original firmware of the Canon camera with a Canon Hack Development Kit. This ‘hacked’ firmware allows us to implement a customized intervalometer script to command the camera to take photographs at user-specified time intervals (e.g., every 3 seconds). This script also allows the user to define several other parameters including: i) time-delay before the camera begins taking pictures, ii) focal length of camera lens, and iii) time before camera automatically shuts down and retracts its lens.

We also use video cameras such as the GoPro Hero and the ContourGPS. These take high definition videos at 1080 x 720 pixels. We attached these cameras underneath or on the side of the fuselage. Using the APM Planner, we program the flight path of each mission by clicking on waypoints in a Google satellite map interface. The drone can be programmed to take off and land autonomously, and circle over any waypoint for a specified number of turns or duration. Users could also program other flight parameters such as ground speed and altitude of each waypoint.

What have we achieved so far?
Since our start in January of this year we have made over 200 conservation drone flights in several countries including Switzerland, Netherlands, Indonesia, Malaysia and Nepal, Congo, Gabon, Madagascar, United States, and Greenland. These flights have provided us a large amount of photos and videos, which we have examined with respect to our three main initial goals. We describe these below.

Mapping land use
So far we have been able to take sets of high-resolution photos of various areas that can be stitched together into a geo-referenced mosaic so that it can be used in geographic information system software. Such mosaics give detailed information on type of land use, agriculture, and settlements. In addition, the images can be used to create three-dimensional models of the areas that were covered during missions due to the overlap between the photos. Such models can potentially be used to calculate a number of characteristics of different land uses such as tree height and tree density.

Biodiversity
The high-resolution nature of our images have also allowed us to detect various wildlife species on our photos or their signs including orangutans and their nests, elephants, rhinos, forest buffaloes, and even turtle nests. The next important step for our work is to derive the distribution and density of these wildlife species based on drone images so that this technique can become a standard application for conservation workers. To achieve this goal, we are collaborating with colleagues, including Prof. Dr. Andreas Krause at ETH Zurich to automate the detection of orangutan nests.

Illegal activities
For conservation workers, having access to up-to-date information on illegal logging in protected areas and poaching are extremely important. The video and photos taken from the drones can be used to detect such these illegal activities. For example, geo-tagged drone images of recently logged areas could help authorities track down illegal loggers and provide evidence for their conviction. When poachers are in a forest, they often create campfires for cooking or smoking the bush-meat from animals they have hunted. The detection of smoke rising above a forest would thus be very useful to locate these poachers. Conservation drones equipped with a high definition video camera could facilitate the detection of smoke many kilometers away. Furthermore, a ‘live’ video link would allow rangers to patrol the forest in real time, and react immediately when needed.

Plans for the future
Conservation Drones is a constant work in progress. We are currently working with other colleagues to explore the use of our drones as a ‘data mule’. For example, drones equipped with a scanning radio receiver might be able to triangulate the location of forest animals that have been tagged with a radio collar. This would be a much more efficient way of locating these radio-collared animals than the traditional method of walking the forest on foot with a cumbersome radio antenna.

We are also working with WWF Nepal and India to equip drones with thermal imaging cameras. These camera systems would be able to detect heat emitting objects from the ground, which would help rangers locate both wildlife and poachers at night.

Further Reading
Koh, L. H., Wich, S. A. (2012) Dawn of drone ecology: low-cost autonomous aerial vehicles for conservation. Tropical Conservation Science 5: 121-132.

www.conservationdrones.org

See all the posts in Robohub’s TED Global 2013 coverage.

Check out live tweets, amazing photos, TED blog posts and awesome video coverage of the session Those Flying Things at this year’s TED Global, featuring the work of automation and controls expert Raffaello D’Andrea, and drone ecologist Lian Pin Koh. We will be adding new material here as it becomes available, so check back soon. Photo credit: James Duncan Davidson.

This post is part of Robohub’s TED Global 2013 coverage.

Update: TED video | Raffaello D’Andrea: The astounding athletic power of quadcopters

Update: TED video | Timelapse: Building an arena for flying robots
See the full TED Blog post for more about how James Duncan Davidson made the video.

Tweets about “quadrotor OR quadrocopter OR drone OR quadcopter OR quadcoptor OR quadrocoptor OR D’Andrea OR Raffaello OR Lian OR Pin OR Koh OR robot OR Suarez #TEDGlobal”

In his TED Global talk titled “Machine Athleticism” Raffaello D’Andrea shows how he uses control algorithms to push quadrotors to perform at their physical limits. Instead of relying on slides, D’Andrea (who is well-known for his quadrotor demos) demonstrates his flying machines live as they toss a ball, balance a poll, serve a glass of water without spilling a drop, and even fly with their props cut off. In his own words, D’Andrea’s talk is about “the ability of machines to perform dynamic feats that fully exploit their physical capabilities.”

Check out official TED blogger Kate Torgovnick for her coverage of Raffaello D’Andrea’s talk.

See all the posts in Robohub’s TED Global 2013 coverage.

A quadrocopter swoops through the air to serve a glass of water without spilling a drop. Another gets two of its propellers cut off, yet still easily flies across the arena. “It looks like magic!” says ETH Zurich‘s Raffaello D’Andrea, but it took a lot of research, hard work and planning to bring this ‘magic trick’ to TED Global.
This post is part of Robohub’s TED Global 2013 coverage.

D’Andrea’s talk is about “Machine Athleticism” — the ability of machines to perform dynamic feats that fully exploit their physical capabilities. Part  of a session called “Those Flying Things” (which also features the work of drone ecologist Lian Pin Koh, airborne logistics activist Andreas Raptopoulos and sci-fi author Daniel Suarez), D’Andrea delves into what it takes to make a machine athlete:

We use something broadly called Model Based Design: we first build physics-based models that roughly capture the behavior of the machine; these models are then leveraged by a branch of mathematics called Control Theory to synthesize algorithms for controlling them.

He goes on to show a series of pretty amazing quadrotor feats that would be impossible without sophisticated automatic feedback. TED just posted an update on their blog about the demo here, and we will link to the video of the talk as soon as it goes online.

Clearly a lot of work has gone on behind the scenes to get D’Andrea and his team to TED. It’s taken years of research and a whole crew of PhD and Master students to develop the infrastructure and algorithms that make this demonstration possible — and that was just to get to the point where they could do the demos in-house.

D’Andrea and his team usually research and demo their quadrotor tricks at the ETH Flying Machine Arena — a 10x10x10m airspace dedicated to the study of control algorithms, and featuring a high-precision motion capture system, a wireless communication network, and custom software for executing estimation and control. Though the FMA normally lives at its home base at the Swiss Federal Institute of Technology (ETH) in Zurich, it was designed from the outset to be portable, and TED Global is not the first time it has taken to the road:
In 2011 they set up at the FRAC Centre in Orléans, France to create a six metre-high tower – the first architectural installation built by flying machines (see video). Last year the team showed their work at the world’s largest industrial fair, Germany’s Hannover Messe and at Google’s annual flagship conference Google IO in San Francisco.

Still, it takes a lot of time and careful planning to recreate the set up at a new site, and on this occasion they were planning a video shoot as well as a live audience. Says Mark Mueller, one of the team members onsite at TED, “Since April, all of us here have been working full-time, 100% on TED,” referring to all the various administrative hurdles they had to cross, such as planning logistics and agreeing on the space, in addition to rehearsing the demo itself. And then there was the packing to do: “It boils down to fifteen cases, boxes and bags,” says Dario Brescianinini, another member of the crew.

D’Andrea and his team arrived in Edinburgh, Scotland (the host city of TED Global 2013) late Saturday afternoon ahead of most other TED speakers, and started setting up almost right away in a dedicated room where the talk was filmed and where all their demonstrations will take place throughout the week. According to Brescianini and Mueller, it took about three-and-a-half hours to get the first quadrotor hovering. On Sunday they rehearsed the talk — and especially the transitions between each demo — in preparation for the video shoot, which was done in advance of the live talk.

Despite a few hiccups (two quads were damaged during setup and some repairs had to be done on the fly), Monday’s shoot went pretty smoothly. “It took about two-and-a-half hours, but we did one talk without breaks and had most of the things filmed after twenty-five minutes,” says Brescianini. It was a busy set, with fifteen TED crew members, seven people from D’Andrea’s team and one photographer. All in all, it took two fixed cameras (4k HD), one Steadicam, and three GoPros (one in the corner on the floor, one on the ceiling facing downwards, and one flying GoPro attached to a quad) to document D’Andrea’s TED talk. An additional camera shot a “making of” video as well. “It’s pretty busy, and we’re all really relieved after the successful filming.”

Want to learn more?
Check out the pages of ETH Zurich’s Flying Machine Arena team and more Robohub articles on how quadrocopters learn acrobatic maneuvers, cooperate to throw and catch balls, perfect air racing, and throw and catch an inverted pendulum.

Full disclosure: Markus Waibel works with Raff D’Andrea and the Flying Machine Arena team at ETH Zurich’s Institute for Dynamic Systems and Control.

See all the posts in Robohub’s TED Global 2013 coverage.

If you liked this article, you may also be interested in:

• Three new quadrotor videos demonstrate agile control and the power of machine learning
• Live at TED Global 2013: Tweets, photos and video for quadrotor fans
• Video: Throwing and catching an inverted pendulum – with quadrocopters
• Quadrocopters learn from prior experience to improve slalom flying

See all the latest robotics news on Robohub, or sign up for our weekly newsletter.

How do you like to go up in a swing,
Up in the air so blue?
Oh, I do think it the pleasantest thing
Ever a child can do!

Child’s Garden of Verses by Robert L. Stephenson

If you’ve ever been a child, chances are that you’ve spent some of your childhood on a swing. And at some point during that time you have probably found out how to move your arms, legs, and body to go higher and higher, without any external help from a friend or parent pushing you – you learned how to pump a swing.

Flavio Fontana, Master student at the ETH Zurich’s Institute for Dynamic Systems and Controls, has taken this concept and used it to control a robot. To make things more challenging, his robot does not just swing, but simultaneously juggles a ball. And, using some neat math to push the idea even further, he and his supervisors Philipp Reist and Raffaello D’Andrea have designed the robot to swing and juggle without cameras – and without ever dropping the ball.

The result of their research is the Swinging Blind Juggler, a robot that juggles a ball from side to side with an actuated paddle attached to a pendulum. The robot is called “blind”, because it has no cameras to “see” the ball. In fact, the Swinging Blind Juggler has no sensors to detect the ball at all.

Here is what Flavio has to say about his video:

In this video, we propose an elegant control strategy for a Swinging Blind Juggler. The key idea is to exploit the dynamic coupling between the motion of the paddle and the pendulum. Children on a swing intuitively use this dynamic coupling to control their amplitude. In a similar way, we control the pendulum with appropriate paddle motions.

So how does this work?

Flavio explains that four conditions must be met for successful juggling:

• First, the paddle used to juggle the ball must have a specific concave shape. This shape will always push the ball back towards the ideal flight path if the ball impact happens to be off-center.
• Second, the paddle has to decelerate as it strikes the ball. This helps to keep the ball bouncing at a consistent height: If the ball flies too high, it will hit the paddle later and hence at a lower speed. Conversely, if the ball flies too low, it will hit the paddle earlier and hence increase the ball’s height on the next bounce.
• Third, the paddle always has to strike the ball at right angles. This ensures that the ball always flies off into the right direction, towards the other side of the swinging motion.
• And fourth, the pendulum must be synchronized to the ball motion. In other words, the pendulum has to reach the peak of its swinging motion at the right time to strike the ball.

To guarantee all of the above, the researchers first derived a mathematical model of the desired motion. Based on these models, they came up with a hardware design that includes a parabolic plate to stabilize the ball’s impact points on the paddle (the first condition), a decelerating paddle motion that stabilizes the ball height (the second condition), and a mechanical mechanism based on four linked bars that automatically tilts the paddle to the right angle for all juggling amplitudes (condition number three).

To meet condition four (to swing back and forth at the right rhythm to hit the ball) the robot can use the same linear motor used to create the decelerating paddle motion for condition two – as long as it still strikes the ball with the right decelerating motion at its peaks. Similar to a child on a playground swing, the robot must raise its body as the swing passes through the lowest point and lower it near the extremes of the motion to pump the swing and swing higher.

The result of the precisely designed hardware setup and control algorithms is a complex motion that’s beautiful to watch – and that blindly juggles a ball from side to side.

To learn more about blind juggling robots, have a look at www.blindjuggler.org.

Note: This post is part of a series that decribes robots developed in Switzerland. If you’d like to contribute a robot to this (or another country’s) series, get in touch at info[@]robohub.org. Like this series? Read more about Swiss Robots!

In the 9th part of the ShanghAI Lecture series, we look at ontogenetic development as Rolf Pfeifer talks about the path from locomotion to cognition. This is followed by two guest lectures: The first one by Ning Lan (Shanghai Jiao Tong University, China) on cortico-muscular communication in the nervous system, the second by Roland Siegwart (ETH Zurich) on the design and navigation of robots with various moving abilities.

The ShanghAI Lectures are a videoconference-based lecture series on Embodied Intelligence run by Rolf Pfeifer and organized by me and partners around the world.

Ning Lan: Cortico-Muscular Communication of Movement Information by Central Regulation of Spindle Sensitivity

Ning Lan is Professor at the Shanghai Jiao Tong University in China. He tells us about cortico-muscular communication in the nervous system.

Roland Siegwart: Design and Navigation of Wheeled, Running, Swimming and Flying Robots

Roland Siegwart is professor at ETH Zurich and the director of the Autonomous Systems Laboratory.

Robots are rapidly evolving from factory work-horses, which are physically bound to their work-cells, to increasingly complex machines capable of performing challenging tasks as search and rescuing, surveillance and inspections, planetary exploration or autonomous transportation of goods. This requires robots to operate in unstructured and unpredictable environments and various terrains. This talk will focus on design and navigation aspects of wheeled, legged, swimming and aerial robots operating in complex environments.

Siegwart presents wheeled inspection robots designed to crawl into machines and take various measurement, quadruped walkers that exploit natural dynamics and serial elastic actuation, swimming robots and autonomous micro-helicopters used to inspect cluttered, GPS denied cities or narrow indoor environments. He also presents a small fixed-wing airplane capable of staying in the air indefinitely due to its solar powered generator.

http://www.youtube.com/watch?v=1jZtOlIrxjY

Related links:

• Slides (17.4 MB)
• ShanghAI Lectures website
• Book: How the Body Shapes the Way We Think

In this sixth part of the ShanghAI Lecture series, Rolf Pfeifer introduces the topic “Artificial Evolution” and gives examples of evolutionary processes in artificial intelligence. The first guest lecture, by Francesco Mondada (EPFL) is about the use of robots in daily life; in the second guest lecture, Robert Riener (ETH Zürich) talks about rehabilitation robots.

The ShanghAI Lectures are a videoconference-based lecture series on Embodied Intelligence run by Rolf Pfeifer and organized by me and partners around the world.

Francesco Mondada: Toward Robots For Daily Life

In a recent survey from the European Commission, 60% of the participants said that robots should be banned from the application area “care of children, elderly, and the disabled”, 34% would like to ban robots from “education”. Within this framework, what is the future of robotics in daily life services? Two research projects answering this question are presented in this talk: education using specific robotics tools and a new form of embodiment for service robotics. Some preliminary results are illustrated, showing a very interesting potential demonstrated by a high acceptance of the proposed approaches.

Robert Riener: Design Principles for Intelligent Rehabilitation Robots

Integrating the human into a robotic rehabilitation system can be challenging not only from a biomechanical view but also with regard to psycho-physiological aspects. Biomechanical integration involves ensuring that the system to be used is ergonomically acceptable and “user-cooperative”. Psycho-physiological integration involves recording and controlling the patient’s physiological reactions so that the patient receives appropriate stimuli and is challenged in a moderate but engaging way. In this talk basic design criteria are presented that should be taken into account, when developing and applying an intelligent robotic system that is in close interaction with the human subject. One must carefully take into account the constraints given by human biomechanical, physiological and psychological functions in order to optimize device function without causing undue stress or harm to the human user.

References:

• Robert Riener, Lars Lünenburger, Gery Colombo: Human-centered robotics applied to gait training and assessment, Journal of Rehabilitation Research and Development, 43(5), August/September 2006, p. 679-694.
• Alexander Koenig, Ximena Omlin, Lukas Zimmerli, Mark Sapa, Carmen Krewer, Marc Bolliger, Friedemann Müller, Robert Riener:Psychological state estimation from physiological recordings during robot-assisted gait rehabilitation, Journal of Rehabilitation Research and Development, 48(4), accepted for publication, 2011
• Robert Riener: What Has to Be Known about Human Physiology to Develop Wearable Robots? Workshop on Wearable Robotics, IEEE ICRA 2012, St. Paul, USA

Related links:

• Slides (9.7 MB)
• ShanghAI Lectures website
• Book: How the Body Shapes the Way We Think

Designing robots that can function outside of controlled, factory environments isn’t easy. When those environments have people in them, they are especially unpredictable and difficult for a robot to navigate.

Enter Rezero: a compact ballbot that can fluidly drive in any direction without prior orientation. Similar in size and shape to a human, Rezero can stabilize, instantly accelerate, avoid obstacles and turn around its own axis. It can also be programmed to follow a path, or a person at a constant distance, and it can even recover from jostles, making it ideal for navigating crowded environments like tradeshows, restaurants, offices and airports.

Possible Rezero applications: personal mobile medical device, telepresence tour guide, personal transportation.

It’s easy to imagine it one day being used to unobtrusively serve drinks at a cocktail event, as a personal mobile device for intravenous equipment at a hospital, or topped with a telepresence device and acting as a museum tour guide. Rezero could even one day rival the Segway as a personal transportation device.

A master of fluidity

Like an inverted pendulum, Rezero (left) balances on a spherical ball; three omniwheels (right) transfer motor action to the ball below.

Rezero’s agility comes from a propulsion and stabilization mechanism that keeps the device balanced on top of a single spherical wheel, like an inverted pendulum; it’s kept from falling over by constantly moving its contact point below its center of gravity.

A sensor called an Inertial Measurement Unit (IMU) measures Rezero’s tilt angle, which is used by an onboard stabilizing controller to compute what kind of motor action is required to keep the system stable. Instructions are then sent to electric motors that actuate three special wheels (called omniwheels), which in turn transfer forces to the sphere below: forces are applied in the rolling direction, but allow for free motion in the lateral direction; opposing each wheel is an arrestor that keeps the ball tightly in place. This process of measuring, computing, and actuating happens 160 times per second, and the underlying controller is key to achieving robust and dynamic movement.

Its ability to quickly respond to a changing environment is what makes Rezero so suitable for human environments, and according to Rezero’s creators, achieving this robustness was their most challenging task. Rezero’s controller is derived from a three-dimensional mathematical model of the system, and can combine complex and fluid movements around all axes. Compared to other ballbots, which can only lean a few degrees, Rezero can tilt up to 17 degrees as it leans into a curve at high speeds.

But getting there wasn’t easy. Rezero was developed in 2009/2010 as an educational project at the Autonomous Systems Lab at ETH Zurich,  and the 13 undergraduate students on the team were responsible for everything from concept to engineering, manufacturing and budgeting.

According to project leader Péter Fankhauser:

“It was the moment we got Rezero to balance for the first time that struck me the most. We got to know the system and work with it and were able to observe how its capabilities improved every day.”

Michael Neunert, his fellow founding team member agrees:

“The development phase was a very intense time. We only had nine months to sketch out our ideas and build Rezero as we see it today.”

Rezero continues to evolve even though some of the original team members have already graduated and moved on. The current team has just finished a new version of the omniwheel, which they have made available to other research groups. They are now working to improve Rezero’s robustness so that it can better manage obstacles in an everyday environment.

Key infos

Robot name: Rezero
Mechanical engineering: Simon Dössegger, Péter Fankhauser, Corsin Gwerder, Jonathan Hüssy, Jérôme Käser, Thomas Kammermann, Lukas Limacher, Michael Neunert
Electrical engineering: Samuel Schüller, Swen Wigert
Industrial design: Jessica Baumgartner, Tu-Van Giang, Claudio Maestretti
Project supervisor: Prof. Dr. Roland Siegwart, Director of the ASL at ETH Zurich
Websites: http://rezero.ethz.ch, TED Talk
Status: Ongoing research project

Photo credits: Rezero in Motion (first photo): Karl-Heinz Hug, Ringier AG; Rezero in the Studio (third photo): Gerhard Born, Ringier AG.

Note: This post is part of our Swiss Robots Series. If you’d like to submit a robot to this series, or to a series for another country, please get in touch at info[@]robohub.org.

What about Cloud Robotics?

The following video briefly explains the general motivation:

Generally, a robotics application interacts with its environment using sensors and actuators. This implies that the data produced by the sensors has to be processed and is normally used as feedback to determine the next action. For actions without hard real-time requirements, processing can be moved to the cloud. This reduces the necessary computing power on the robot, which can improve operation duration for mobile systems and may decrease costs.

Simplified cloud model: Each robot is connected to its own clone in the cloud (rectangular boxes), which are tightly interconnected with each other and with the databases (circular disks).

Many common high-level robotics tasks, such as planning or mapping, don’t require hard real-time. Mapping, for example, involves storing a reusable description of the environment to allow the robot to localize a landmark or itself. Additionally, maps can be used on a large scale to plan trajectories for moving to a landmark or on a small scale to grasp an object, which in turn might include querying an object database for grasp points to get the best position to grab the object. Because planning can be done ahead of time (i.e. act instead of react), it has no hard real-time constraints.

The advantages of offloading computation to the cloud can be even more pronounced when considering collaborative robot scenarios. For example, sharing data when creating a common map, or negotiating a cooperative plan when performing a common task can be more easily achieved with a centralized architecture with powerful computational capabilities.

RoboEarth allows robots to share knowledge in a centralized knowledge base. This centralized approach has the advantage of avoiding duplicate information and the necessity to constantly exchange newly generated knowledge to avoid duplicate learning. However, to benefit from the full potential of this approach not only requires a centralized storage of knowledge, but also centralized reasoning, i.e. a framework for cloud computation for robots.

The missing piece

Until now, RoboEarth only provided data storage for robots. With the introduction of Rapyuta, the RoboEarth Cloud Engine, the missing piece in the cloud infrastructure for robots is added. Rapyuta provides a platform where robots can create computing environments to offload there heavy computation into the cloud. These computing environments can either function as a personal cloud for individual robots or be shared by multiple robots. Additionally, computing environments have high-bandwidth connections to the RoboEarth database, allowing their processes to quickly access knowledge.

Technical aspects

Simplified overview of Rapyuta: The robots are connected to Rapyuta’s communications module in the cloud. Similarly, the cloud applications running inside the computing environments (LXC) are also connected to the communications module. The module manages communications from and to all connected elements.

To simplify the deployment and interaction of the cloud applications Rapyuta, similar to the Google App Engine, defines a protocol for cloud applications. However, in contrast to Google’s model where only web requests are used to communicate directly with the cloud application, Rapyuta introduces an additional layer. This means, a robot does not communicate directly with a cloud application, but uses Rapyuta as a medium. This model gives more flexibility and control over the system. For example, Rapyuta can be used as a relay to communicate directly between robots without the creation of a computing environment. Furthermore, the additional layer implies that Rapyuta allows to run multiple processes using sockets to communicate with each other. Google’s App Engine, however, prevents this, because web applications have no need for communicating processes to service web requests.

On the robot side Rapyuta uses common web protocols that allow access via a web browser. Like rosbridge and ros.js, Rapyuta uses WebSockets for persistent connections and JavaScript Object Notation (JSON) compatible strings for messages. However, because rosbridge provides only a subset of the functionality of Rapyuta the two protocols are not compatible. The main reason for this is that Rapyuta allows the client to interact with more than one ROS environment, i.e. computing environments, over the same connection, which leads to a more complex protocol for Rapyuta.

On the cloud application side the message system defined by the Robot Operating System (ROS) is used. This allows to deploy and run most of the more than 3’000 existing ROS packages (i.e., ROS applications) with minimal to no changes in the RoboEarth Cloud Engine.

To separate the ROS nodes, i.e. the cloud applications, for different users, Rapyuta provides individual computing environments. A robot can have many computing environments and a computing environment can be used by many robots, which allows a variety of deployment models. Linux Containers (LXC) were chosen for the implementation of computing environment to securely control all operational aspects such as communication as well as CPU, RAM, and disk usage. Additionally, Rapyuta allows different computing environments to communicate with each other using the ROS messaging system.

Rapyuta is open source. The Rapyuta Alpha release is available on github under the Apache License, Version 2.0.

For more information have a look at the Rapyuta documentation.

Further reading:

• Analysis: Robot learning in the cloud