In the last six years, (2010–2015), according to the IFR (International Federation of Robotics), US industry has installed around 135,000 new industrial robots. The principal driver is automation in the car industry. During this same period, (2010–2015), the number of employees in the automotive sector increased by 230,000.
Craft brewing could be the perfect industry for collaborative robots. But, does automation mean losing your artisan status? We find how craft breweries can use robotics to scale-up their business without compromising on quality.
Please note: The following article may contain spoilers up to Episode 5 of Westworld.
HBO’s Westworld (on Sky Atlantic here in the UK) is progressing nicely, though even now at five episodes in it’s probably a little too early to start speculating about what is going on exactly. However, at the risk of casting wild speculations that hindsight later proves naive, one character that is particularly interesting: Anthony Hopkin’s Dr. Robert Ford.
In October, the U.S.-China Economic and Security Review Commission released a report, China’s Industrial and Military Robotics Development, prepared by the Defense Group, Inc. at the Commission’s request. The report examines the development of China’s unmanned industrial, service, and military robotics systems, such as drones and driverless cars, and the economic and national security implications of these trends for the United States.
Electric motors have been around since Thomas Davenport built the first functional model in 1834, and they have played a growing part in our lives ever since. Today, they continue to replace diesel and gas engines, as well as hydraulic cylinders, while evolving into new designs optimized for robots and other technologies.
“Something like 40 percent of electric power is used to drive motors, and that number will only grow,” says James Kirtley, a professor in MIT’s Department of Electrical Engineering and Computer Science and in MIT’s Research Laboratory of Electronics. “Electric motors are being used more widely in ships, airplanes, trains, and cars. We’re also seeing a lot more electric motors in robots.”
The ongoing transition from gas to electric is primarily driven by the need for more efficient devices that run with cleaner energy sources. Yet, electric motors also tend to be more responsive, and are more adaptable to new applications, especially in smaller devices.
As one of the world’s leading experts on electric motors, Kirtley’s philosophy is that one size does not fit all. “If you take into account the specific application, you can build a motor that is far better adapted than a general purpose motor,” says Kirtley. “For example, I’m working with someone who is making robots for medical assist, and he needs motors with very special characteristics.”
Many of the newer types of electric motors tend to be much smaller and run on less power than in the past. “I started working with electric motors 40 years ago designing big nuclear generators with 20-foot long rotors that were 6 feet in diameter and could produce a gigawatt and a half of power,” says Kirtley. “I’m now building motors on the order of 100 to 200 Watts for appliance motors, which are kinder and gentler to the system powering them. In the automotive industry, the average automobile has dozens of small motors for things like door locks, wiper blades, air conditioning, and seat positioners.”
Even excluding the separate field of MEMS (micro-electromechanical systems), which Kirtley is not directly involved in, electric motors are now shrinking to as small as the 1 W devices found in cell phones. A variety of innovative new compact motors are being developed all over MIT, says Kirtley, who points to an interesting variable reluctance motor for a prosthetic foot being designed at MIT’s Center for Art, Science and Technology.
Clean transportation is another source of innovation in electric motors. “In my lab we’re doing work with a small company in Cambridge that makes bicycle assist wheels,” says Kirtley. “The wheel stores some energy, and can react to pedaling forces to help it climb hills. These are entirely new applications.”
Improving microgrids with smart motors
Kirtley’s early involvement with power-plant generators led him to study electric power systems. His research into the subject culminated in 2010 with his Wiley-published book, “Electric Power Principles.” Lately, he’s been focusing on the customer-end of the system, where he is finding a role for electric motors in helping distribution systems adapt to intermittent, user-generated solar power.
“Electric power distribution systems are being stretched by the growing use of distributed renewable generation, such as rooftop solar,” says Kirtley. “Typically, electricity is transmitted from large power plants through extra high voltage wires, and the voltage is stepped down and delivered to customers. The problem with rooftop solar is that it looks to the power system like a reduction in load, but as solar cells become more widespread, homes will at times be able to produce more power than they’re consuming. So the power flows backward, which makes everything more complicated.”
Utilities are now working on smart microgrids that can adapt to distributed, multidirectional power. The greater flexibility is primarily enabled by smarter electronics, as well as efficient, distributed battery storage. Yet, microgrids still have a problem with even brief power outages, which can sometimes cause them to shut down.
“We’re thinking about the dynamics of motors connected to microgrids, and how you can improve their stability and make them work better,” Kirtley says. “We’re concerned about continuity of supply, which is especially important with microgrids supporting large server farms. You don’t want your system to be forced into an involuntary reboot simply because you had a glitch in the electric power supply. Electric motors can add more reliability.”
Electrifying the Cheetah robot
Many of the recent innovations in electric motors are found in robotics, which need smarter motors that can reliably deliver variable levels of power on demand for short periods. Electric motors can provide mobile robots with significantly longer battery life compared to traditional hydraulic systems. “Hydraulics are controlled primarily through throttle valves, so a lot of energy is wasted pumping and controlling the hydraulic fluid,” says Kirtley.
Kirtley has been working with Professor Jeffrey Lang on developing customized electric motors for Department of Mechanical Engineering colleague Sangbae Kim’s robotic cheetah, a running, jumping quadruped that has gained widespread publicity in recent years. The cheetah’s new motor is not only more efficient, but also more powerful, although only in short intervals.
“A secondary advantage of electric motors is responsiveness and control,” says Kirtley. “We can build a motor that can produce considerable torque in short spikes, even if we can’t necessarily produce the forces for a long period of time. It’s perhaps a little too powerful for the cheetah, which can now jump so high in the air, it probably wouldn’t survive the landing if they didn’t catch it.”
Electric motors transform ships
Most commercial ships still use diesel engines, while many naval vessels use gas turbine engines. Yet shipping is quickly moving toward electric propulsion, motivated primarily by efficiency, says Kirtley. Aside from nuclear-powered vessels, these tend to be hybrid systems in which diesel or gas generators drive an electric motor.
“A traditional gear drive for ships has some very decided disadvantages,” he says. “For example, most destroyers in the U.S. Navy have gearboxes with very precise machining requirements, and are therefore expensive. They also require a fixed gear ratio between the engine and the water, so the prime mover is not operating near its peak fuel efficiency. Because of that, much of commercial shipping, and virtually all cruise ships, are now moving to electric propulsion, and even the U.S. Navy is starting to use it for its latest destroyer.”
The other problem with fuel-driven gear-drive engines is “the tyranny of the shaft line,” says Kirtley. “If you’re going to use a direct gear drive, the engine, gearbox, and propeller must line up very precisely, which often takes up valuable real estate within the body of the ship. With electric propulsion, we don’t have that problem. The engines can be placed anywhere where it’s convenient. In cruise ships, for example, the motors are place in a pod underneath the ship.”
Electric cars: adapting the engine to the road
The main difference between electric propulsion on ships vs. cars is related to torque requirements, says Kirtley. “On a ship, top speed defines the torque requirement,” he explains. “Automobile propulsion occurs across a speed range of about 10 to 1, with an engine that idles at 600 rpm capable of redlining at about 6,000 rpm. The best motors for cars are those that are adaptable to a very wide speed range.”
The variable speeds used in a car require that “the gearbox adapt the engine to the road,” says Kirtley. “You can generate an electric motor that can propel an automobile without a gear shift.”
In the past, Kirtley has consulted with Tesla Motors on its electric cars, and both agree that “the induction motor is the best for electric automobiles,” says Kirtley. Many other electric car manufacturers are still using permanent magnet motors, which he says are intrinsically less efficient in the wide speed and torque range required by car propulsion.
“For any given electric motor there is a tradeoff between excitation — making the operating magnetic field within the machine — and reaction, providing current to push on that exciting field inside the machine,” explains Kirtley. “In a permanent magnet machine that field is constant and cannot be adjusted, so a machine that is turning very fast but making relatively little torque is dropping a lot of power in losses in the machine’s magnetic iron. In an induction motor you can back off on the excitation to provide torque at the energetically optimal fashion. You can improve the drive efficiency of a car over a complete drive cycle by as much of a factor of two in fewer losses.”
Induction motors aren’t optimal for all applications, however, which brings Kirtley back to his main thesis: “In the development of motors for modern applications, it is most important to understand the totality of operational requirements,” he says. “That is key to making electric motors that will accomplish what they do best: provide motion in a responsive and efficient fashion.”
Sarah Hensley is preparing an astronaut named Valkyrie for a mission to Mars. It is 6 feet tall, weighs 300 pounds, and is equipped with an extended chest cavity that makes it look distinctly female. Hensley spends much of her time this semester analyzing the movements of one of Valkyrie’s arms.
Less than 100 years from now, robots will be friendly, useful participants in our homes and workplaces, predicts UBC mechanical engineering professor and robotics expert Elizabeth Croft. We will be living in a world of Wall-Es and Rosies, walking-and-talking avatars, smart driverless cars and automated medical assistants.
In experiments involving a simulation of the human esophagus and stomach, researchers at MIT, the University of Sheffield, and the Tokyo Institute of Technology have demonstrated a tiny origami robot that can unfold itself from a swallowed capsule and, steered by external magnetic fields, crawl across the stomach wall to remove a swallowed button battery or patch a wound.
The new work, which the researchers are presenting this week at the International Conference on Robotics and Automation, builds on a long sequence of papers on origamirobots from the research group of Daniela Rus, the Andrew and Erna Viterbi Professor in MIT’s Department of Electrical Engineering and Computer Science.
“It’s really exciting to see our small origami robots doing something with potential important applications to health care,” says Rus, who also directs MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL). “For applications inside the body, we need a small, controllable, untethered robot system. It’s really difficult to control and place a robot inside the body if the robot is attached to a tether.”
Joining Rus on the paper are first author Shuhei Miyashita, who was a postdoc at CSAIL when the work was done and is now a lecturer in electronics at the University of York, in England; Steven Guitron, a graduate student in mechanical engineering; Shuguang Li, a CSAIL postdoc; Kazuhiro Yoshida of Tokyo Institute of Technology, who was visiting MIT on sabbatical when the work was done; and Dana Damian of the University of Sheffield, in England.
Although the new robot is a successor to one reported at the same conference last year, the design of its body is significantly different. Like its predecessor, it can propel itself using what’s called a “stick-slip” motion, in which its appendages stick to a surface through friction when it executes a move, but slip free again when its body flexes to change its weight distribution.
Also like its predecessor — and like several other origami robots from the Rus group — the new robot consists of two layers of structural material sandwiching a material that shrinks when heated. A pattern of slits in the outer layers determines how the robot will fold when the middle layer contracts.
The robot’s envisioned use also dictated a host of structural modifications. “Stick-slip only works when, one, the robot is small enough and, two, the robot is stiff enough,” says Guitron. “With the original Mylar design, it was much stiffer than the new design, which is based on a biocompatible material.”
To compensate for the biocompatible material’s relative malleability, the researchers had to come up with a design that required fewer slits. At the same time, the robot’s folds increase its stiffness along certain axes.
But because the stomach is filled with fluids, the robot doesn’t rely entirely on stick-slip motion. “In our calculation, 20 percent of forward motion is by propelling water — thrust — and 80 percent is by stick-slip motion,” says Miyashita. “In this regard, we actively introduced and applied the concept and characteristics of the fin to the body design, which you can see in the relatively flat design.”
It also had to be possible to compress the robot enough that it could fit inside a capsule for swallowing; similarly, when the capsule dissolved, the forces acting on the robot had to be strong enough to cause it to fully unfold. Through a design process that Guitron describes as “mostly trial and error,” the researchers arrived at a rectangular robot with accordion folds perpendicular to its long axis and pinched corners that act as points of traction.
In the center of one of the forward accordion folds is a permanent magnet that responds to changing magnetic fields outside the body, which control the robot’s motion. The forces applied to the robot are principally rotational. A quick rotation will make it spin in place, but a slower rotation will cause it to pivot around one of its fixed feet. In the researchers’ experiments, the robot uses the same magnet to pick up the button battery.
The researchers tested about a dozen different possibilities for the structural material before settling on the type of dried pig intestine used in sausage casings. “We spent a lot of time at Asian markets and the Chinatown market looking for materials,” Li says. The shrinking layer is a biodegradable shrink wrap called Biolefin.
To design their synthetic stomach, the researchers bought a pig stomach and tested its mechanical properties. Their model is an open cross-section of the stomach and esophagus, molded from a silicone rubber with the same mechanical profile. A mixture of water and lemon juice simulates the acidic fluids in the stomach.
Every year, 3,500 swallowed button batteries are reported in the U.S. alone. Frequently, the batteries are digested normally, but if they come into prolonged contact with the tissue of the esophagus or stomach, they can cause an electric current that produces hydroxide, which burns the tissue. Miyashita employed a clever strategy to convince Rus that the removal of swallowed button batteries and the treatment of consequent wounds was a compelling application of their origami robot.
“Shuhei bought a piece of ham, and he put the battery on the ham,” Rus says. “Within half an hour, the battery was fully submerged in the ham. So that made me realize that, yes, this is important. If you have a battery in your body, you really want it out as soon as possible.”
“This concept is both highly creative and highly practical, and it addresses a clinical need in an elegant way,” says Bradley Nelson, a professor of robotics at the Swiss Federal Institute of Technology Zurich. “It is one of the most convincing applications of origami robots that I have seen.”
Should you always do what other people tell you to do? Clearly not. Everyone knows that. So should future robots always obey our commands? At first glance, you might think they should, simply because they are machines and that’s what they are designed to do. But then think of all the times you would not mindlessly carry out others’ instructions – and put robots into those situations.
One reason we don’t yet have robot personal assistants buzzing around doing our chores is because making them is hard. Assembling robots by hand is time-consuming, while automation — robots building other robots — is not yet fine-tuned enough to make robots that can do complex tasks.
Fellow Robots, in partnership with Lowes Hardware, today launched the OSHbot as a customer assistant robot at the Orchard Supply Hardware store in San Jose. Although the robot can only give information, this trial will help determine what sort of benefit a robot assistant can provide, both to customers and to store associates.