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#439693 Agility Robotics’ Digit is Getting ...
Agility Robotics' Digit humanoid has been taking a bit of a break from work during the pandemic. Most of what we've seen from Agility and Digit over the past year and a half has been decidedly research-y. Don't get me wrong, Digit's been busy making humans look bad and not falling over when it really should have done, but remember that Agility's goal is to make Digit into a useful, practical robot. It's not a research platform—as Agility puts it, Digit is intended to “accelerate business productivity and people's pursuit of a more fulfilling life.” As far as I can make out, this is a fancier way of saying that Digit should really be spending its time doing dull repetitive tasks so that humans don't have to, and in a new video posted today, the robot shows how it can help out with boring warehouse tote shuffling.
The highlights here for me are really in the combination of legged mobility and object manipulation. Right at the beginning of the video, you see Digit squatting all the way down, grasping a tote bin, shuffling backwards to get the bin out from under the counter, and then standing again. There's an unfortunate cut there, but the sequence is shown again at 0:44, and you can see how Digit pulls the tote towards itself and then regrasps it before lifting. Clever. And at 1:20, the robot gives a tote that it just placed on a shelf a little nudge with one arm to make sure it's in the right spot.
These are all very small things, but I think of them as highlights because all of the big things seem to be more or less solved in this scenario. Digit has no problem lifting things, walking around, and not mowing over the occasional human, and once that stuff is all sorted, whether the robot is able to effectively work in an environment like this is to some extent reflected in all of these other little human-obvious things that often make the difference between success and failure.
The clear question, though, is why Digit (or, more broadly, any bipedal robot) is the right robot to be doing this kind of job. There are other robots out there already doing tasks like these in warehouses, and they generally have wheeled bases and manipulation systems specifically designed to move totes and do nothing else. If you were to use one of those robots instead of Digit, my guess is that you'd pay less for it, it would be somewhat safer, and it would likely do the job more efficiently. Fundamentally, Digit can't out box-move a box-moving robot. But the critical thing to consider here is that as soon as you run out of boxes to move, Digit can do all kinds of other things thanks to its versatile humanoid design, while your box-moving robot can only sit in the corner and be sad until more boxes show up.
“We did not set out to build a humanoid robot. We set out to solve mobility.”
—Agility CTO Jonathan Hurst
“Digit is very, very flexible automation,” Agility CTO Jonathan Hurst told us when we asked him about this. “The value of what we're doing is in generality, and having a robot that's going be able to work carrying totes for three or four hours, then go unload boxes from trailers for three or four hours, keep up with you if you change your workflow entirely. Many of these spaces are designed specifically around the human form factor, and it's possible for a robot like Digit to do all of these different boring, repetitive jobs. And then when things get complicated, humans are still doing it.”
The value of having a human-like robot in a human environment comes into play as soon as you start thinking about typical warehouse situations that would be trivial for a human to solve but that are impossible for wheeled robots. For example, Hurst says that Digit is capable of using a stool to reach objects on high shelves. You could, of course, design a wheeled robot with an extension system to allow it to reach high shelves, but you're now adding more cost and complexity, and the whole point of a generalist humanoid robot is that in human environments, you just don't have to worry about environmental challenges. Or that's the idea, anyway, but as Hurst explains, the fact that Digit ended up with a mostly humanoid form factor was more like a side effect of designing with specific capabilities in mind:
We did not set out to build a humanoid robot. We set out to solve mobility, and we've been on a methodical path towards understanding physical interaction in the world. Agility started with our robot Cassie, and one of the big problems with Cassie was that we didn't have enough inertia in the robot's body to counteract the leg swinging forward, which is why Digit has an upright torso. We wanted to give ourselves more control authority in the yaw direction with Cassie, so we experimented with putting a tail on the robot, and it turns out that the best tail is a pair of bilaterally symmetrical tails, one on either side.
Our goal was to design a machine that can go where people go while manipulating things in the world, and we ended up with this kind of form factor. It's a very different path for us to have gotten here than the vast majority of humanoid robots, and there's an awful lot of subtlety that is in our machine that is absent in most other machines.IEEE Spectrum: So are you saying that Digit's arms sort of started out as tails to help Cassie with yaw control?
Jonathan Hurst: There are many examples like this—we've been going down this path where we find a solution to a problem like yaw control, and it happens to look like it does with animals, but it's also a solution that's optimal in several different ways, like physical interaction and being able to catch the robot when it falls. It's not like it's a compromise between one thing and another thing, it's straight up the right solution for these three different performance design goals.
Looking back, we started by asking, should we put a reaction wheel or a gyro on Cassie for yaw control? Well, that's just wasted mass. We could use a tail, and there are a lot of nice robots with tails, but usually they're for controlling pitch. It's the same with animals; if you look at lizards, they use their tails for mid-air reorienting to land on their feet after they jump. Cassie doesn't need a tail for that, but we only have a couple of small feet on the ground to work with. And if you look at other bipedal animals, every one of them has some other way of getting that yaw authority. If you watch an ostrich run, when it turns, it sticks its wing out to get the control that it needs.
And so all of these things just fall into place, and a bilaterally symmetrical pair of tails is the best way to control yaw in a biped. When you see Digit walking and its arms are swinging, that's not something that we added to make the motion look right. It looks right because it literally is right—it's the physics of mobility. And that's a good sign for us that we're on the right path to getting the performance that we want.
“We're going for general purpose, but starting with some of the easiest use cases.”
—Agility CTO Jonathan Hurst
Spectrum: We've seen Digit demonstrating very impressive mobility skills. Why are we seeing a demo in a semi-constrained warehouse environment instead of somewhere that would more directly leverage Digit's unique advantages?
Jonathan Hurst: It's about finding the earliest, most appropriate, and most valuable use cases. There's a lot to this robot, and we're not going to be just a tote packing robot. We're not building a specialized robot for this one application, but we have a couple of pretty big logistics partners who are interested in the flexibility and the manipulation capabilities of this machine. And yeah, what you're seeing now is the robot on a flattish floor, but it's also not going to be tripped up by a curb, or a step, or, a wire cover, or other things on the ground. You don't have to worry about anything like that. So next, it's an easy transition next to unloading trailers, where it's going to have to be stepping over gaps and up and down things and around boxes on the floor and stuff like that. We're going for general purpose, but starting with some of the easiest use cases.
Damion Shelton, CEO: We're trying to prune down the industry space, to get to something where there's a clear value proposition with a partner and deploying there. We can respect the difficulty of the general purpose use case and work to deploy early and profitably, as opposed to continuing to push for the outdoor applications. The blessing and the curse of the Ford opportunity is that it's super interesting, but also super hard. And so it's very motivating, and it's clear to us that that's where one of the ultimate opportunities is, but it's also far enough away from a deployment timeline that it just doesn't map on to a viable business model.
This is a point that every robotics company runs into sooner or later, where aspirations have to succumb to the reality of selling robots in a long-term sustainable way. It's definitely not a bad thing, it just means that we may have to adjust our expectations accordingly. No matter what kind of flashy cutting-edge capabilities your robot has, if it can't cost effectively do dull or dirty or dangerous stuff, nobody's going to pay you money for it. And cost effective usefulness is, arguably, one of the biggest challenges in bipedal robotics right now. In the past, I've been impressed by Digit's weightlifting skills, or its ability to climb steep and muddy hills. I'll be just as impressed when it starts making money for Agility by doing boring repetitive tasks in warehouses, because that means that Agility will be able to keep working towards those more complex, more exciting things. “It's not general manipulation, and we're not solving the grand challenges of robotics,” says Hurst. “Yet. But we're on our way.” Continue reading
Posted in Human Robots
#439105 This Robot Taught Itself to Walk in a ...
Recently, in a Berkeley lab, a robot called Cassie taught itself to walk, a little like a toddler might. Through trial and error, it learned to move in a simulated world. Then its handlers sent it strolling through a minefield of real-world tests to see how it’d fare.
And, as it turns out, it fared pretty damn well. With no further fine-tuning, the robot—which is basically just a pair of legs—was able to walk in all directions, squat down while walking, right itself when pushed off balance, and adjust to different kinds of surfaces.
It’s the first time a machine learning approach known as reinforcement learning has been so successfully applied in two-legged robots.
This likely isn’t the first robot video you’ve seen, nor the most polished.
For years, the internet has been enthralled by videos of robots doing far more than walking and regaining their balance. All that is table stakes these days. Boston Dynamics, the heavyweight champ of robot videos, regularly releases mind-blowing footage of robots doing parkour, back flips, and complex dance routines. At times, it can seem the world of iRobot is just around the corner.
This sense of awe is well-earned. Boston Dynamics is one of the world’s top makers of advanced robots.
But they still have to meticulously hand program and choreograph the movements of the robots in their videos. This is a powerful approach, and the Boston Dynamics team has done incredible things with it.
In real-world situations, however, robots need to be robust and resilient. They need to regularly deal with the unexpected, and no amount of choreography will do. Which is how, it’s hoped, machine learning can help.
Reinforcement learning has been most famously exploited by Alphabet’s DeepMind to train algorithms that thrash humans at some the most difficult games. Simplistically, it’s modeled on the way we learn. Touch the stove, get burned, don’t touch the damn thing again; say please, get a jelly bean, politely ask for another.
In Cassie’s case, the Berkeley team used reinforcement learning to train an algorithm to walk in a simulation. It’s not the first AI to learn to walk in this manner. But going from simulation to the real world doesn’t always translate.
Subtle differences between the two can (literally) trip up a fledgling robot as it tries out its sim skills for the first time.
To overcome this challenge, the researchers used two simulations instead of one. The first simulation, an open source training environment called MuJoCo, was where the algorithm drew upon a large library of possible movements and, through trial and error, learned to apply them. The second simulation, called Matlab SimMechanics, served as a low-stakes testing ground that more precisely matched real-world conditions.
Once the algorithm was good enough, it graduated to Cassie.
And amazingly, it didn’t need further polishing. Said another way, when it was born into the physical world—it knew how to walk just fine. In addition, it was also quite robust. The researchers write that two motors in Cassie’s knee malfunctioned during the experiment, but the robot was able to adjust and keep on trucking.
Other labs have been hard at work applying machine learning to robotics.
Last year Google used reinforcement learning to train a (simpler) four-legged robot. And OpenAI has used it with robotic arms. Boston Dynamics, too, will likely explore ways to augment their robots with machine learning. New approaches—like this one aimed at training multi-skilled robots or this one offering continuous learning beyond training—may also move the dial. It’s early yet, however, and there’s no telling when machine learning will exceed more traditional methods.
And in the meantime, Boston Dynamics bots are testing the commercial waters.
Still, robotics researchers, who were not part of the Berkeley team, think the approach is promising. Edward Johns, head of Imperial College London’s Robot Learning Lab, told MIT Technology Review, “This is one of the most successful examples I have seen.”
The Berkeley team hopes to build on that success by trying out “more dynamic and agile behaviors.” So, might a self-taught parkour-Cassie be headed our way? We’ll see.
Image Credit: University of California Berkeley Hybrid Robotics via YouTube Continue reading
Posted in Human Robots
#439077 How Scientists Grew Human Muscles in Pig ...
The little pigs bouncing around the lab looked exceedingly normal. Yet their adorable exterior hid a remarkable secret: each piglet carried two different sets of genes. For now, both sets came from their own species. But one day, one of those sets may be human.
The piglets are chimeras—creatures with intermingled sets of genes, as if multiple entities were seamlessly mashed together. Named after the Greek lion-goat-serpent monsters, chimeras may hold the key to an endless supply of human organs and tissues for transplant. The crux is growing these human parts in another animal—one close enough in size and function to our own.
Last week, a team from the University of Minnesota unveiled two mind-bending chimeras. One was joyous little piglets, each propelled by muscles grown from a different pig. Another was pig embryos, transplanted into surrogate pigs, that developed human muscles for more than 20 days.
The study, led by Drs. Mary and Daniel Garry at the University of Minnesota, had a therapeutic point: engineering a brilliant way to replace muscle loss, especially for the muscles around our skeletons that allow us to move and navigate the world. Trauma and injury, such as from firearm wounds or car crashes, can damage muscle tissue beyond the point of repair. Unfortunately, muscles are also stubborn in that donor tissue from cadavers doesn’t usually “take” at the injury site. For now, there are no effective treatments for severe muscle death, called volumetric muscle loss.
The new human-pig hybrids are designed to tackle this problem. Muscle wasting aside, the study also points to a clever “hack” that increases the amount of human tissue inside a growing pig embryo.
If further improved, the technology could “provide an unlimited supply of organs for transplantation,” said Dr. Mary Garry to Inverse. What’s more, because the human tissue can be sourced from patients themselves, the risk of rejection by the immune system is relatively low—even when grown inside a pig.
“The shortage of organs for heart transplantation, vascular grafting, and skeletal muscle is staggering,” said Garry. Human-animal chimeras could have a “seismic impact” that transforms organ transplantation and helps solve the organ shortage crisis.
That is, if society accepts the idea of a semi-humanoid pig.
Wait…But How?
The new study took a page from previous chimera recipes.
The main ingredients and steps go like this: first, you need an embryo that lacks the ability to develop a tissue or organ. This leaves an “empty slot” of sorts that you can fill with another set of genes—pig, human, or even monkey.
Second, you need to fine-tune the recipe so that the embryos “take” the new genes, incorporating them into their bodies as if they were their own. Third, the new genes activate to instruct the growing embryo to make the necessary tissue or organs without harming the overall animal. Finally, the foreign genes need to stay put, without cells migrating to another body part—say, the brain.
Not exactly straightforward, eh? The piglets are technological wonders that mix cutting-edge gene editing with cloning technologies.
The team went for two chimeras: one with two sets of pig genes, the other with a pig and human mix. Both started with a pig embryo that can’t make its own skeletal muscles (those are the muscles surrounding your bones). Using CRISPR, the gene-editing Swiss Army Knife, they snipped out three genes that are absolutely necessary for those muscles to develop. Like hitting a bullseye with three arrows simultaneously, it’s already a technological feat.
Here’s the really clever part: the muscles around your bones have a slightly different genetic makeup than the ones that line your blood vessels or the ones that pump your heart. While the resulting pig embryos had severe muscle deformities as they developed, their hearts beat as normal. This means the gene editing cut only impacted skeletal muscles.
Then came step two: replacing the missing genes. Using a microneedle, the team injected a fertilized and slightly developed pig egg—called a blastomere—into the embryo. If left on its natural course, a blastomere eventually develops into another embryo. This step “smashes” the two sets of genes together, with the newcomer filling the muscle void. The hybrid embryo was then placed into a surrogate, and roughly four months later, chimeric piglets were born.
Equipped with foreign DNA, the little guys nevertheless seemed totally normal, nosing around the lab and running everywhere without obvious clumsy stumbles. Under the microscope, their “xenomorph” muscles were indistinguishable from run-of-the-mill average muscle tissue—no signs of damage or inflammation, and as stretchy and tough as muscles usually are. What’s more, the foreign DNA seemed to have only developed into muscles, even though they were prevalent across the body. Extensive fishing experiments found no trace of the injected set of genes inside blood vessels or the brain.
A Better Human-Pig Hybrid
Confident in their recipe, the team next repeated the experiment with human cells, with a twist. Instead of using controversial human embryonic stem cells, which are obtained from aborted fetuses, they relied on induced pluripotent stem cells (iPSCs). These are skin cells that have been reverted back into a stem cell state.
Unlike previous attempts at making human chimeras, the team then scoured the genetic landscape of how pig and human embryos develop to find any genetic “brakes” that could derail the process. One gene, TP53, stood out, which was then promptly eliminated with CRISPR.
This approach provides a way for future studies to similarly increase the efficiency of interspecies chimeras, the team said.
The human-pig embryos were then carefully grown inside surrogate pigs for less than a month, and extensively analyzed. By day 20, the hybrids had already grown detectable human skeletal muscle. Similar to the pig-pig chimeras, the team didn’t detect any signs that the human genes had sprouted cells that would eventually become neurons or other non-muscle cells.
For now, human-animal chimeras are not allowed to grow to term, in part to stem the theoretical possibility of engineering humanoid hybrid animals (shudder). However, a sentient human-pig chimera is something that the team specifically addressed. Through multiple experiments, they found no trace of human genes in the embryos’ brain stem cells 20 and 27 days into development. Similarly, human donor genes were absent in cells that would become the hybrid embryos’ reproductive cells.
Despite bioethical quandaries and legal restrictions, human-animal chimeras have taken off, both as a source of insight into human brain development and a well of personalized organs and tissues for transplant. In 2019, Japan lifted its ban on developing human brain cells inside animal embryos, as well as the term limit—to global controversy. There’s also the question of animal welfare, given that hybrid clones will essentially become involuntary organ donors.
As the debates rage on, scientists are nevertheless pushing the limits of human-animal chimeras, while treading as carefully as possible.
“Our data…support the feasibility of the generation of these interspecies chimeras, which will serve as a model for translational research or, one day, as a source for xenotransplantation,” the team said.
Image Credit: Christopher Carson on Unsplash Continue reading
Posted in Human Robots