Tag Archives: hand

#439023 In ‘Klara and the Sun,’ We Glimpse ...

Posted on March 25, 2021 by Android

In a store in the center of an unnamed city, humanoid robots are displayed alongside housewares and magazines. They watch the fast-moving world outside the window, anxiously awaiting the arrival of customers who might buy them and take them home. Among them is Klara, a particularly astute robot who loves the sun and wants to learn as much as possible about humans and the world they live in.

So begins Kazuo Ishiguro’s new novel Klara and the Sun, published earlier this month. The book, told from Klara’s perspective, portrays an eerie future society in which intelligent machines and other advanced technologies have been integrated into daily life, but not everyone is happy about it.

Technological unemployment, the progress of artificial intelligence, inequality, the safety and ethics of gene editing, increasing loneliness and isolation—all of which we’re grappling with today—show up in Ishiguro’s world. It’s like he hit a fast-forward button, mirroring back to us how things might play out if we don’t approach these technologies with caution and foresight.

The wealthy genetically edit or “lift” their children to set them up for success, while the poor have to make do with the regular old brains and bodies bequeathed them by evolution. Lifted and unlifted kids generally don’t mix, and this is just one of many sinister delineations between a new breed of haves and have-nots.

There’s anger about robots’ steady infiltration into everyday life, and questions about how similar their rights should be to those of humans. “First they take the jobs. Then they take the seats at the theater?” one woman fumes.

References to “changes” and “substitutions” allude to an economy where automation has eliminated millions of jobs. While “post-employed” people squat in abandoned buildings and fringe communities arm themselves in preparation for conflict, those whose livelihoods haven’t been destroyed can afford to have live-in housekeepers and buy Artificial Friends (or AFs) for their lonely children.

“The old traditional model that we still live with now—where most of us can get some kind of paid work in exchange for our services or the goods we make—has broken down,” Ishiguro said in a podcast discussion of the novel. “We’re not talking just about the difference between rich and poor getting bigger. We’re talking about a gap appearing between people who participate in society in an obvious way and people who do not.”

He has a point; as much as techno-optimists claim that the economic changes brought by automation and AI will give us all more free time, let us work less, and devote time to our passion projects, how would that actually play out? What would millions of “post-employed” people receiving basic income actually do with their time and energy?

In the novel, we don’t get much of a glimpse of this side of the equation, but we do see how the wealthy live. After a long wait, just as the store manager seems ready to give up on selling her, Klara is chosen by a 14-year-old girl named Josie, the daughter of a woman who wears “high-rank clothes” and lives in a large, sunny home outside the city. Cheerful and kind, Josie suffers from an unspecified illness that periodically flares up and leaves her confined to her bed for days at a time.

Her life seems somewhat bleak, the need for an AF clear. In this future world, the children of the wealthy no longer go to school together, instead studying alone at home on their digital devices. “Interaction meetings” are set up for them to learn to socialize, their parents carefully eavesdropping from the next room and trying not to intervene when there’s conflict or hurt feelings.

Klara does her best to be a friend, aide, and confidante to Josie while continuing to learn about the world around her and decode the mysteries of human behavior. We surmise that she was programmed with a basic ability to understand emotions, which evolves along with her other types of intelligence. “I believe I have many feelings. The more I observe, the more feelings become available to me,” she explains to one character.

Ishiguro does an excellent job of representing Klara’s mind: a blend of pre-determined programming, observation, and continuous learning. Her narration has qualities both robotic and human; we can tell when something has been programmed in—she “Gives Privacy” to the humans around her when that’s appropriate, for example—and when she’s figured something out for herself.

But the author maintains some mystery around Klara’s inner emotional life. “Does she actually understand human emotions, or is she just observing human emotions and simulating them within herself?” he said. “I suppose the question comes back to, what are our emotions as human beings? What do they amount to?”

Klara is particularly attuned to human loneliness, since she essentially was made to help prevent it. It is, in her view, peoples’ biggest fear, and something they’ll go to great lengths to avoid, yet can never fully escape. “Perhaps all humans are lonely,” she says.

Warding off loneliness through technology isn’t a futuristic idea, it’s something we’ve been doing for a long time, with the technologies at hand growing more and more sophisticated. Products like AFs already exist. There’s XiaoIce, a chatbot that uses “sentiment analysis” to keep its 660 million users engaged, and Azuma Hikari, a character-based AI designed to “bring comfort” to users whose lives lack emotional connection with other humans.

The mere existence of these tools would be sinister if it wasn’t for their widespread adoption; when millions of people use AIs to fill a void in their lives, it raises deeper questions about our ability to connect with each other and whether technology is building it up or tearing it down.

This isn’t the only big question the novel tackles. An overarching theme is one we’ve been increasingly contemplating as computers start to acquire more complex capabilities, like the beginnings of creativity or emotional awareness: What is it that truly makes us human?

“Do you believe in the human heart?” one character asks. “I don’t mean simply the organ, obviously. I’m speaking in the poetic sense. The human heart. Do you think there is such a thing? Something that makes each of us special and individual?”

The alternative, at least in the story, is that people don’t have a unique essence, but rather we’re all a blend of traits and personalities that can be reduced to strings of code. Our understanding of the brain is still elementary, but at some level, doesn’t all human experience boil down to the firing of billions of neurons between our ears? Will we one day—in a future beyond that painted by Ishiguro, but certainly foreshadowed by it—be able to “decode” our humanity to the point that there’s nothing mysterious left about it? “A human heart is bound to be complex,” Klara says. “But it must be limited.”

Whether or not you agree, Klara and the Sun is worth the read. It’s both a marvelous, engaging story about what it means to love and be human, and a prescient warning to approach technological change with caution and nuance. We’re already living in a world where AI keeps us company, influences our behavior, and is wreaking various forms of havoc. Ishiguro’s novel is a snapshot of one of our possible futures, told through the eyes of a robot who keeps you rooting for her to the end.

Image Credit: Marion Wellmann from Pixabay Continue reading →

Posted in Human Robots

#438807 Visible Touch: How Cameras Can Help ...

Posted on March 5, 2021 by Android

The dawn of the robot revolution is already here, and it is not the dystopian nightmare we imagined. Instead, it comes in the form of social robots: Autonomous robots in homes and schools, offices and public spaces, able to interact with humans and other robots in a socially acceptable, human-perceptible way to resolve tasks related to core human needs.

To design social robots that “understand” humans, robotics scientists are delving into the psychology of human communication. Researchers from Cornell University posit that embedding the sense of touch in social robots could teach them to detect physical interactions and gestures. They describe a way of doing so by relying not on touch but on vision.

A USB camera inside the robot captures shadows of hand gestures on the robot’s surface and classifies them with machine-learning software. They call this method ShadowSense, which they define as a modality between vision and touch, bringing “the high resolution and low cost of vision-sensing to the close-up sensory experience of touch.”

Touch-sensing in social or interactive robots is usually achieved with force sensors or capacitive sensors, says study co-author Guy Hoffman of the Sibley School of Mechanical and Aerospace Engineering at Cornell University. The drawback to his group’s approach has been that, even to achieve coarse spatial resolution, many sensors are needed in a small area.

However, working with non-rigid, inflatable robots, Hoffman and his co-researchers installed a consumer-grade USB camera to which they attached a fisheye lens for a wider field of vision.

“Given that the robot is already hollow, and has a soft and translucent skin, we could do touch interaction by looking at the shadows created by people touching the robot,” says Hoffman. They used deep neural networks to interpret the shadows. “And we were able to do it with very high accuracy,” he says. The robot was able to interpret six different gestures, including one- or two-handed touch, pointing, hugging and punching, with an accuracy of 87.5 to 96 percent, depending on the lighting.

This is not the first time that computer vision has been used for tactile sensing, though the scale and application of ShadowSense is unique. “Photography has been used for touch mainly in robotic grasping,” says Hoffman. By contrast, Hoffman and collaborators wanted to develop a sense that could be “felt” across the whole of the device.

The potential applications for ShadowSense include mobile robot guidance using touch, and interactive screens on soft robots. A third concerns privacy, especially in home-based social robots. “We have another paper currently under review that looks specifically at the ability to detect gestures that are further away [from the robot’s skin],” says Hoffman. This way, users would be able to cover their robot’s camera with a translucent material and still allow it to interpret actions and gestures from shadows. Thus, even though it’s prevented from capturing a high-resolution image of the user or their surrounding environment, using the right kind of training datasets, the robot can continue to monitor some kinds of non-tactile activities.

In its current iteration, Hoffman says, ShadowSense doesn’t do well in low-light conditions. Environmental noise, or shadows from surrounding objects, also interfere with image classification. Relying on one camera also means a single point of failure. “I think if this were to become a commercial product, we would probably [have to] work a little bit better on image detection,” says Hoffman.

As it was, the researchers used transfer learning—reusing a pre-trained deep-learning model in a new problem—for image analysis. “One of the problems with multi-layered neural networks is that you need a lot of training data to make accurate predictions,” says Hoffman. “Obviously, we don’t have millions of examples of people touching a hollow, inflatable robot. But we can use pre-trained networks trained on general images, which we have billions of, and we only retrain the last layers of the network using our own dataset.” Continue reading →

Posted in Human Robots

#438801 This AI Thrashes the Hardest Atari Games ...

Posted on March 4, 2021 by Android

Learning from rewards seems like the simplest thing. I make coffee, I sip coffee, I’m happy. My brain registers “brewing coffee” as an action that leads to a reward.

That’s the guiding insight behind deep reinforcement learning, a family of algorithms that famously smashed most of Atari’s gaming catalog and triumphed over humans in strategy games like Go. Here, an AI “agent” explores the game, trying out different actions and registering ones that let it win.

Except it’s not that simple. “Brewing coffee” isn’t one action; it’s a series of actions spanning several minutes, where you’re only rewarded at the very end. By just tasting the final product, how do you learn to fine-tune grind coarseness, water to coffee ratio, brewing temperature, and a gazillion other factors that result in the reward—tasty, perk-me-up coffee?

That’s the problem with “sparse rewards,” which are ironically very abundant in our messy, complex world. We don’t immediately get feedback from our actions—no video-game-style dings or points for just grinding coffee beans—yet somehow we’re able to learn and perform an entire sequence of arm and hand movements while half-asleep.

This week, researchers from UberAI and OpenAI teamed up to bestow this talent on AI.

The trick is to encourage AI agents to “return” to a previous step, one that’s promising for a winning solution. The agent then keeps a record of that state, reloads it, and branches out again to intentionally explore other solutions that may have been left behind on the first go-around. Video gamers are likely familiar with this idea: live, die, reload a saved point, try something else, repeat for a perfect run-through.

The new family of algorithms, appropriately dubbed “Go-Explore,” smashed notoriously difficult Atari games like Montezuma’s Revenge that were previously unsolvable by its AI predecessors, while trouncing human performance along the way.

It’s not just games and digital fun. In a computer simulation of a robotic arm, the team found that installing Go-Explore as its “brain” allowed it to solve a challenging series of actions when given very sparse rewards. Because the overarching idea is so simple, the authors say, it can be adapted and expanded to other real-world problems, such as drug design or language learning.

Growing Pains
How do you reward an algorithm?

Rewards are very hard to craft, the authors say. Take the problem of asking a robot to go to a fridge. A sparse reward will only give the robot “happy points” if it reaches its destination, which is similar to asking a baby, with no concept of space and danger, to crawl through a potential minefield of toys and other obstacles towards a fridge.

“In practice, reinforcement learning works very well, if you have very rich feedback, if you can tell, ‘hey, this move is good, that move is bad, this move is good, that move is bad,’” said study author Joost Huinzinga. However, in situations that offer very little feedback, “rewards can intentionally lead to a dead end. Randomly exploring the space just doesn’t cut it.”

The other extreme is providing denser rewards. In the same robot-to-fridge example, you could frequently reward the bot as it goes along its journey, essentially helping “map out” the exact recipe to success. But that’s troubling as well. Over-holding an AI’s hand could result in an extremely rigid robot that ignores new additions to its path—a pet, for example—leading to dangerous situations. It’s a deceptive AI solution that seems effective in a simple environment, but crashes in the real world.

What we need are AI agents that can tackle both problems, the team said.

Intelligent Exploration
The key is to return to the past.

For AI, motivation usually comes from “exploring new or unusual situations,” said Huizinga. It’s efficient, but comes with significant downsides. For one, the AI agent could prematurely stop going back to promising areas because it thinks it had already found a good solution. For another, it could simply forget a previous decision point because of the mechanics of how it probes the next step in a problem.

For a complex task, the end result is an AI that randomly stumbles around towards a solution while ignoring potentially better ones.

“Detaching from a place that was previously visited after collecting a reward doesn’t work in difficult games, because you might leave out important clues,” Huinzinga explained.

Go-Explore solves these problems with a simple principle: first return, then explore. In essence, the algorithm saves different approaches it previously tried and loads promising save points—once more likely to lead to victory—to explore further.

Digging a bit deeper, the AI stores screen caps from a game. It then analyzes saved points and groups images that look alike as a potential promising “save point” to return to. Rinse and repeat. The AI tries to maximize its final score in the game, and updates its save points when it achieves a new record score. Because Atari doesn’t usually allow people to revisit any random point, the team used an emulator, which is a kind of software that mimics the Atari system but with custom abilities such as saving and reloading at any time.

The trick worked like magic. When pitted against 55 Atari games in the OpenAI gym, now commonly used to benchmark reinforcement learning algorithms, Go-Explore knocked out state-of-the-art AI competitors over 85 percent of the time.

It also crushed games previously unbeatable by AI. Montezuma’s Revenge, for example, requires you to move Pedro, the blocky protagonist, through a labyrinth of underground temples while evading obstacles such as traps and enemies and gathering jewels. One bad jump could derail the path to the next level. It’s a perfect example of sparse rewards: you need a series of good actions to get to the reward—advancing onward.

Go-Explore didn’t just beat all levels of the game, a first for AI. It also scored higher than any previous record for reinforcement learning algorithms at lower levels while toppling the human world record.

Outside a gaming environment, Go-Explore was also able to boost the performance of a simulated robot arm. While it’s easy for humans to follow high-level guidance like “put the cup on this shelf in a cupboard,” robots often need explicit training—from grasping the cup to recognizing a cupboard, moving towards it while avoiding obstacles, and learning motions to not smash the cup when putting it down.

Here, similar to the real world, the digital robot arm was only rewarded when it placed the cup onto the correct shelf, out of four possible shelves. When pitted against another algorithm, Go-Explore quickly figured out the movements needed to place the cup, while its competitor struggled with even reliably picking the cup up.

Combining Forces
By itself, the “first return, then explore” idea behind Go-Explore is already powerful. The team thinks it can do even better.

One idea is to change the mechanics of save points. Rather than reloading saved states through the emulator, it’s possible to train a neural network to do the same, without needing to relaunch a saved state. It’s a potential way to make the AI even smarter, the team said, because it can “learn” to overcome one obstacle once, instead of solving the same problem again and again. The downside? It’s much more computationally intensive.

Another idea is to combine Go-Explore with an alternative form of learning, called “imitation learning.” Here, an AI observes human behavior and mimics it through a series of actions. Combined with Go-Explore, said study author Adrien Ecoffet, this could make more robust robots capable of handling all the complexity and messiness in the real world.

To the team, the implications go far beyond Go-Explore. The concept of “first return, then explore” seems to be especially powerful, suggesting “it may be a fundamental feature of learning in general.” The team said, “Harnessing these insights…may be essential…to create generally intelligent agents.”

Image Credit: Adrien Ecoffet, Joost Huizinga, Joel Lehman, Kenneth O. Stanley, and Jeff Clune Continue reading →

Posted in Human Robots

#438785 Video Friday: A Blimp For Your Cat

Posted on February 28, 2021 by Android

Video Friday is your weekly selection of awesome robotics videos, collected by your Automaton bloggers. We’ll also be posting a weekly calendar of upcoming robotics events for the next few months; here's what we have so far (send us your events!):

HRI 2021 – March 8-11, 2021 – [Online Conference]
RoboSoft 2021 – April 12-16, 2021 – [Online Conference]
ICRA 2021 – May 30-5, 2021 – Xi'an, China
Let us know if you have suggestions for next week, and enjoy today's videos.

Shiny robotic cat toy blimp!

I am pretty sure this is Google Translate getting things wrong, but the About page mentions that the blimp will “take you to your destination after appearing in the death of God.”

[ NTT DoCoMo ] via [ RobotStart ]

If you have yet to see this real-time video of Perseverance landing on Mars, drop everything and watch it.

During the press conference, someone commented that this is the first time anyone on the team who designed and built this system has ever seen it in operation, since it could only be tested at the component scale on Earth. This landing system has blown my mind since Curiosity.

Here's a better look at where Percy ended up:

[ NASA ]

The fact that Digit can just walk up and down wet, slippery, muddy hills without breaking a sweat is (still) astonishing.

[ Agility Robotics ]

SkyMul wants drones to take over the task of tying rebar, which looks like just the sort of thing we'd rather robots be doing so that we don't have to:

The tech certainly looks promising, and SkyMul says that they're looking for some additional support to bring things to the pilot stage.

[ SkyMul ]

Thanks Eohan!

Flatcat is a pet-like, playful robot that reacts to touch. Flatcat feels everything exactly: Cuddle with it, romp around with it, or just watch it do weird things of its own accord. We are sure that flatcat will amaze you, like us, and caress your soul.

I don't totally understand it, but I want it anyway.

[ Flatcat ]

Thanks Oswald!

This is how I would have a romantic dinner date if I couldn't get together in person. Herman the UR3 and an OptiTrack system let me remotely make a romantic meal!

[ Dave's Armoury ]

Here, we propose a novel design of deformable propellers inspired by dragonfly wings. The structure of these propellers includes a flexible segment similar to the nodus on a dragonfly wing. This flexible segment can bend, twist and even fold upon collision, absorbing force upon impact and protecting the propeller from damage.

[ Paper ]

Thanks Van!

In the 1970s, The CIA​ created the world's first miniaturized unmanned aerial vehicle, or UAV, which was intended to be a clandestine listening device. The Insectothopter was never deployed operationally, but was still revolutionary for its time.

It may never have been deployed (not that they'll admit to, anyway), but it was definitely operational and could fly controllably.

[ CIA ]

Research labs are starting to get Digits, which means we're going to get a much better idea of what its limitations are.

[ Ohio State ]

This video shows the latest achievements for LOLA walking on undetected uneven terrain. The robot is technically blind, not using any camera-based or prior information on the terrain.

[ TUM ]

We define “robotic contact juggling” to be the purposeful control of the motion of a three-dimensional smooth object as it rolls freely on a motion-controlled robot manipulator, or “hand.” While specific examples of robotic contact juggling have been studied before, in this paper we provide the first general formulation and solution method for the case of an arbitrary smooth object in single-point rolling contact on an arbitrary smooth hand.

[ Paper ]

Thanks Fan!

A couple of new cobots from ABB, designed to work safely around humans.

[ ABB ]

Thanks Fan!

It's worth watching at least a little bit of Adam Savage testing Spot's new arm, because we get to see Spot try, fail, and eventually succeed at an autonomous door-opening behavior at the 10 minute mark.

[ Tested ]

SVR discusses diversity with guest speakers Dr. Michelle Johnson from the GRASP Lab at UPenn; Dr Ariel Anders from Women in Robotics and first technical hire at Robust.ai; Alka Roy from The Responsible Innovation Project; and Kenechukwu C. Mbanesi and Kenya Andrews from Black in Robotics. The discussion here is moderated by Dr. Ken Goldberg—artist, roboticist and Director of the CITRIS People and Robots Lab—and Andra Keay from Silicon Valley Robotics.

[ SVR ]

RAS presents a Soft Robotics Debate on Bioinspired vs. Biohybrid Design.

In this debate, we will bring together experts in Bioinspiration and Biohybrid design to discuss the necessary steps to make more competent soft robots. We will try to answer whether bioinspired research should focus more on developing new bioinspired material and structures or on the integration of living and artificial structures in biohybrid designs.

[ RAS SoRo ]

IFRR presents a Colloquium on Human Robot Interaction.

Across many application domains, robots are expected to work in human environments, side by side with people. The users will vary substantially in background, training, physical and cognitive abilities, and readiness to adopt technology. Robotic products are expected to not only be intuitive, easy to use, and responsive to the needs and states of their users, but they must also be designed with these differences in mind, making human-robot interaction (HRI) a key area of research.

[ IFRR ]

Vijay Kumar, Nemirovsky Family Dean and Professor at Penn Engineering, gives an introduction to ENIAC day and David Patterson, Pardee Professor of Computer Science, Emeritus at the University of California at Berkeley, speaks about the legacy of the ENIAC and its impact on computer architecture today. This video is comprised of lectures one and two of nine total lectures in the ENIAC Day series.

There are more interesting ENIAC videos at the link below, but we'll highlight this particular one, about the women of the ENIAC, also known as the First Programmers.

[ ENIAC Day ] Continue reading →

Posted in Human Robots

#438755 Soft Legged Robot Uses Pneumatic ...

Posted on February 24, 2021 by Android

Soft robots are inherently safe, highly resilient, and potentially very cheap, making them promising for a wide array of applications. But development on them has been a bit slow relative to other areas of robotics, at least partially because soft robots can’t directly benefit from the massive increase in computing power and sensor and actuator availability that we’ve seen over the last few decades. Instead, roboticists have had to get creative to find ways of achieving the functionality of conventional robotics components using soft materials and compatible power sources.

In the current issue of Science Robotics, researchers from UC San Diego demonstrate a soft walking robot with four legs that moves with a turtle-like gait controlled by a pneumatic circuit system made from tubes and valves. This air-powered nervous system can actuate multiple degrees of freedom in sequence from a single source of pressurized air, offering a huge reduction in complexity and bringing a very basic form of decision making onto the robot itself.

Generally, when people talk about soft robots, the robots are only mostly soft. There are some components that are very difficult to make soft, including pressure sources and the necessary electronics to direct that pressure between different soft actuators in a way that can be used for propulsion. What’s really cool about this robot is that researchers have managed to take a pressure source (either a single tether or an onboard CO2 cartridge) and direct it to four different legs, each with three different air chambers, using an oscillating three valve circuit made entirely of soft materials.

Photo: UCSD

The pneumatic circuit that powers and controls the soft quadruped.

The inspiration for this can be found in biology—natural organisms, including quadrupeds, use nervous system components called central pattern generators (CPGs) to prompt repetitive motions with limbs that are used for walking, flying, and swimming. This is obviously more complicated in some organisms than in others, and is typically mediated by sensory feedback, but the underlying structure of a CPG is basically just a repeating circuit that drives muscles in sequence to produce a stable, continuous gait. In this case, we’ve got pneumatic muscles being driven in opposing pairs, resulting in a diagonal couplet gait, where diagonally opposed limbs rotate forwards and backwards at the same time.

Diagram: Science Robotics

(J) Pneumatic logic circuit for rhythmic leg motion. A constant positive pressure source (P+) applied to three inverter components causes a high-pressure state to propagate around the circuit, with a delay at each inverter. While the input to one inverter is high, the attached actuator (i.e., A1, A2, or A3) is inflated. This sequence of high-pressure states causes each pair of legs of the robot to rotate in a direction determined by the pneumatic connections. (K) By reversing the sequence of activation of the pneumatic oscillator circuit, the attached actuators inflate in a new sequence (A1, A3, and A2), causing (L) the legs of the robot to rotate in reverse. (M) Schematic bottom view of the robot with the directions of leg motions indicated for forward walking.

Diagram: Science Robotics

Each of the valves acts as an inverter by switching the normally closed half (top) to open and the normally open half (bottom) to closed.

The circuit itself is made up of three bistable pneumatic valves connected by tubing that acts as a delay by providing resistance to the gas moving through it that can be adjusted by altering the tube’s length and inner diameter. Within the circuit, the movement of the pressurized gas acts as both a source of energy and as a signal, since wherever the pressure is in the circuit is where the legs are moving. The simplest circuit uses only three valves, and can keep the robot walking in one single direction, but more valves can add more complex leg control options. For example, the researchers were able to use seven valves to tune the phase offset of the gait, and even just one additional valve (albeit of a slightly more complex design) could enable reversal of the system, causing the robot to walk backwards in response to input from a soft sensor. And with another complex valve, a manual (tethered) controller could be used for omnidirectional movement.

This work has some similarities to the rover that JPL is developing to explore Venus—that rover isn’t a soft robot, of course, but it operates under similar constraints in that it can’t rely on conventional electronic systems for autonomous navigation or control. It turns out that there are plenty of clever ways to use mechanical (or in this case, pneumatic) intelligence to make robots with relatively complex autonomous behaviors, meaning that in the future, soft (or soft-ish) robots could find valuable roles in situations where using a non-compliant system is not a good option.

For more on why we should be so excited about soft robots and just how soft a soft robot needs to be, we spoke with Michael Tolley, who runs the Bioinspired Robotics and Design Lab at UCSD, and Dylan Drotman, the paper’s first author.

IEEE Spectrum: What can soft robots do for us that more rigid robotic designs can’t?

Michael Tolley: At the very highest level, one of the fundamental assumptions of robotics is that you have rigid bodies connected at joints, and all your motion happens at these joints. That's a really nice approach because it makes the math easy, frankly, and it simplifies control. But when you look around us in nature, even though animals do have bones and joints, the way we interact with the world is much more complicated than that simple story. I’m interested in where we can take advantage of material properties in robotics. If you look at robots that have to operate in very unknown environments, I think you can build in some of the intelligence for how to deal with those environments into the body of the robot itself. And that’s the category this work really falls under—it's about navigating the world.

Dylan Drotman: Walking through confined spaces is a good example. With the rigid legged robot, you would have to completely change the way that the legs move to walk through a confined space, while if you have flexible legs, like the robot in our paper, you can use relatively simple control strategies to squeeze through an area you wouldn’t be able to get through with a rigid system.

How smart can a soft robot get?

Drotman: Right now we have a sensor on the front that's connected through a fluidic transmission to a bistable valve that causes the robot to reverse. We could add other sensors around the robot to allow it to change direction whenever it runs into an obstacle to effectively make an electronics-free version of a Roomba.

Tolley: Stepping back a little bit from that, one could make an argument that we’re using basic memory elements to generate very basic signals. There’s nothing in principle that would stop someone from making a pneumatic computer—it’s just very complicated to make something that complex. I think you could build on this and do more intelligent decision making, but using this specific design and the components we’re using, it’s likely to be things that are more direct responses to the environment.

How well would robots like these scale down?

Drotman: At the moment we’re manufacturing these components by hand, so the idea would be to make something more like a printed circuit board instead, and looking at how the channel sizes and the valve design would affect the actuation properties. We’ll also be coming up with new circuits, and different designs for the circuits themselves.

Tolley: Down to centimeter or millimeter scale, I don’t think you’d have fundamental fluid flow problems. I think you’re going to be limited more by system design constraints. You’ll have to be able to locomote while carrying around your pressure source, and possibly some other components that are also still rigid. When you start to talk about really small scales, though, it's not as clear to me that you really need an intrinsically soft robot. If you think about insects, their structural geometry can make them behave like they’re soft, but they’re not intrinsically soft.

Should we be thinking about soft robots and compliant robots in the same way, or are they fundamentally different?

Tolley: There’s certainly a connection between the two. You could have a compliant robot that behaves in a very similar way to an intrinsically soft robot, or a robot made of intrinsically soft materials. At that point, it comes down to design and manufacturing and practical limitations on what you can make. I think when you get down to small scales, the two sort of get connected.

There was some interesting work several years ago on using explosions to power soft robots. Is that still a thing?

Tolley: One of the opportunities with soft robots is that with material compliance, you have the potential to store energy. I think there’s exciting potential there for rapid motion with a soft body. Combustion is one way of doing that with power coming from a chemical source all at once, but you could also use a relatively weak muscle that over time stores up energy in a soft body and then releases it.

Is it realistic to expect complete softness from soft robots, or will they likely always have rigid components because they have to store or generate and move pressurized gas somehow?

Tolley: If you look in nature, you do have soft pumps like the heart, but although it’s soft, it’s still relatively stiff. Like, if you grab a heart, it’s not totally squishy. I haven’t done it, but I’d imagine. If you have a container that you’re pressurizing, it has to be stiff enough to not just blow up like a balloon. Certainly pneumatics or hydraulics are not the only way to go for soft actuators; there has been some really nice work on smart muscles and smart materials like hydraulic electrostatic (HASEL) actuators. They seem promising, but all of these actuators have challenges. We’ve chosen to stick with pressurized pneumatics in the near term; longer term, I think you’ll start to see more of these smart material actuators become more practical.

Personally, I don’t have any problem with soft robots having some rigid components. Most animals on land have some rigid components, but they can still take advantage of being soft, so it’s probably going to be a combination. But I do also like the vision of making an entirely soft, squishy thing. Continue reading →

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