The foldable quadrotor is small enough to fit in a hand (Photo: LIS, EPFL, NCCR Robotics).

The use of robots to find victims after natural disasters is fast becoming commonplace, with well documented cases where robots have been sent into areas too dangerous for rescue workers.  While the issues surrounding robustness, control and autonomy are frequently cited as key areas for research, a  team from LIS, EPFL and NCCR Robotics is working on another important aspect, how to make flying robots easily transportable and quick to deploy.

In a paper, which will be presented at the International Conference on Robotics and Automation (ICRA) 2015, the team describes how they made a quadrotor with rapidly self-deploying, folding arms. Foldable aerial platforms currently use either beams or detachable appendages (e.g. DJI spreading wings series and SenseFly eBee), which require manipulation by the user, slowing the process down and introducing the possibility of human error. The presented prototype has self-deploying arms that go from completely stowed to ready-to-use in 0.3 seconds, meaning that multiple drones can be utilized at once in a very short period of time.

The origami arms are stored using a system of strategically placed magnets, which can use the torque and thrust generated by the propellers to break the magnetic seal, thus allowing the arms to deploy when the quadrotor is switched on. In order to make use of such a simple mechanism, the design team carefully considered the placement of the folds in the arms; to take advantage of the propeller’s torque, folds are parallel to the its axis.

The origami structures that make up the arms allow them to fold around the central core, reducing its volume to about a third of commercial quadrotors of a similar weight. To make the origami structures, the arms are constructed from a 0.3mm layer of fiberglass over Icarex, a lightweight and inextensible fabric. Two vertical folds in the 2D structure allow the arms to lie in the wrapped configuration. When the motor begins, the action of the propellers forces the magnets apart and allows the arm to straighten in its flat configuration, whereupon a second set of magnets attract and pull the horizontal fold (down the centre of the arm) closed, creating a stiff, 3D structure with no need for heavy locking mechanisms.

First author Stefano Mintchev holds the quadrotor (Photo: LIS, EPFL, Alain Herzog).

The folding quadrotor currently doesn’t have an automatic “putting away” mode, meaning that the arms must be manually returned to the wrapped configuration. However, at the deployment stage, where speed is of the essence when trying to locate vulnerable people, this mechanism may just be a lifesaver.

Reference

S. Mintchev, L. Daler, G. L’Eplattenier, L. Saint-Raymond & D. Floreano, “Foldable and Self-Deployable Pocket Sized Quadrotor,” In 2015 IEEE International conference on Robotics and Automation (ICRA 2015), Seattle, Washington, USA, May 26-30, 2015.  A pdf of the full article can be downloaded from infoscience.

Photo credit: Robotics & Perception Group, University of Zurich.

When a drone flies close to a building, it can temporarily lose its GPS signal and position information, possibly leading to a crash. To ensure safety, a fall-back system is needed to help the quadrotor regain stable flight as soon as possible. We developed a new technology that allows a quadrotor to automatically recover and stabilize from any initial condition without relying on external infrastructure like GPS. The technology allows the quadrotor system to be used safely both indoors and out, to recover stable flight after a GPS loss or system failure. And because the recovery is so quick, it even works to recover flight after an aggressive throw, allowing you to launch a quadrotor simply by tossing it in the air like a baseball.

How it works

Photo credit: Robotics & Perception Group, University of Zurich.

Our quadrotor is equipped with a single camera, an inertial measurement unit, and a distance sensor (Teraranger One). The stabilization system of the quadrotor emulates the visual system and the sense of balance within humans. As soon as a toss or a failure situation is detected, our computer-vision software analyses the images for distinctive landmarks in the environment, and uses these to restore balance.

All the image processing and control runs on a smartphone processor on board the drone. The onboard sensing and computation renders the drone safe and able to fly unaided. This allows the drone to fulfil its mission without any communication or interaction with the operator.

The recovery procedure consists of multiple stages. First, the quadrotor stabilizes its attitude and altitude, and then it re-initializes its visual state-estimation pipeline before stabilizing fully autonomously. To experimentally demonstrate the performance of our system, in the video we aggressively throw the quadrotor in the air by hand and have it recover and stabilize all by itself. We chose this example as it simulates conditions similar to failure recovery during aggressive flight. Our system was able to recover successfully in several hundred throws in both indoor and outdoor environments.

More info: Robotics and Perception Group, University of Zurich.

References

• Quadrocopter failsafe algorithm: Recovery after propeller loss
• Video: Throwing and catching an inverted pendulum – with quadrocopters
• Developing trust in autonomous robots: Seminar with Michael Wagner
• From sideshow to main event, drones are making their mark in entertainment

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

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.

While not yet a shipping product, AlwaysInnovating’s MeCam appears to be close to being so.

Operating under voice command, the MeCam can be set in a mode where it keeps its camera focused on you and follows you around, streaming the video to a phone or tablet, from which it can easily be shared on the social media site of your choice.

The design is available to manufacturers and social media companies for licensing now.

Gizmag has more detail.