Humanoid robots learn to fall well

Smart marketers at Boston Dynamics produced two major robotics news series last week. The larger of them was, after all, an announcement of the electrical Atlas. As I write this, the sub-40-second video is steadily approaching five million views. The day before, the corporate touched the hearts of the community by announcing that the unique Hydraulic Atlas can be put out to pasture ten years after its launch.

An accompanying video celebrated the older Atlas’ journey from a DARPA research project to an impressively agile bipedal “bot.” But after a minute, the tone changes. Ultimately, Farewell to Atlas is each a celebration and a bummer. It’s a pleasant reminder that each time a robot captures a landing on video, there are dozens of slips, falls and snorts.

I actually have long advocated for this sort of transparency. This is something I would really like to see more of on the planet of robotics. Just showing a highlight reel hurts the hassle that went into making those shots. In many cases, we’re talking about years of trial and error that led to robots looking good on camera. By sharing only positive results, you set unrealistic expectations. Bipedal robots fall over. At least on this respect they’re the identical as us. As agility put it down recently“Everyone falls sometimes. How we rise up defines us.” I’d go a step further and add that learning to fall well is equally necessary.

The company’s newly appointed CTO, Pras Velagapudi, recently told me that seeing robots get to work at this stage is definitely a great thing. “When a robot is actually in the world doing real things, unexpected things will happen,” he notes. “You’re going to see some falls, but that’s part of learning to run for a really long time in real-world conditions. This is to be expected and is a sign that you are not staging anything.”

A fast review of Harvard’s policies for a fall without injury reflects what we intuitively understand concerning the fall as humans:

1. Protect your head
2. Use your weight to guide your fall
3. bend your knees
4. Avoid taking other individuals with you

As for robots, yes Excerpt from last yr’s IEEE Spectrum is an amazing place to start.

“We’re not afraid of failure — we don’t treat robots as if they’re going to break down all the time,” Boston Dynamics chief technology officer Aaron Saunders said last yr. “Our robot falls a lot, and one of the things we decided a long time ago is that we need to build robots that can fall without breaking. If you can go through the cycle of bringing the robot to failure, investigating the failure, and repairing it, you can make progress to the point where the robot does not fall. But if you build a machine, control system, or culture that never falls, you will never learn what you need to learn to keep the robot from falling. We celebrate falls, even those that break the robot.”

Image credits: Boston dynamics

The topic of decline also got here up after I spoke with Boston Dynamics CEO Robert Playter ahead of the launch of the electrical Atlas. It’s value noting that the short video starts with the robot in a prone position. The way the robot’s legs arch is kind of novel, because it allows the system to get up from a totally flat position. At first glance, you would possibly get the impression that the corporate is showing off through the use of this flashy movement simply to showcase its extremely durable, custom-made actuators.

“It will be a very practical application,” Playter told me. “Robots will fall. You higher have the option to stand up from a lying position. He adds that the power to stand up from a lying position may also be useful for charging.

Much of Boston Dynamics’ knowledge about falls comes from Spot. While the four-legged chassis is usually more stable (as evidenced by many years of trying to kick robots in movies and failing), Spot Robots are simply lots more workable in real-world conditions.

Image credits: Agile robotics

“The Spot travels approximately 70,000 km per year around production halls and conducts approximately 100,000 inspections per month,” adds Playter. “Eventually they fall. You have to be able to get up. We hope you slow down your rate of descent – we do. I think we fall once every 100-200 km. The rate of decline is really slow, but it does happen.”

Playter adds that the corporate has a protracted history of being “harsh” with its robots. “They are falling and so they have to survive. Fingers cannot fall off.

Watching the Atlas videos above, it’s hard not to transfer a little bit of human empathy to the “bot”. It really does feel prefer it’s falling like a human, pulling its limbs as close to its body as possible to protect them from further injury.

When Agility added arms to Digit in 2019, they discussed the role they played in falls. “For us, arms are at once a tool for navigating the world – think of getting up after a fall, swinging your arms for balance, or opening doors – while also being useful for manipulating or moving objects” – co-founder Jonathan Hurst then noticed.

I talked a bit about this with Agility at Modex earlier this yr. A video circulated on social media of the Digit robot collapsing on the convention floor the yr before. “With a 99% success rate in approximately 20 hours of live demonstration, Digit still had a few downs in ProMat,” Agility noted on the time. “We have no evidence, but we believe our sales team arranged this so they could talk about Digit’s quick-change limbs and durability.”

As with the Atlas video, the corporate told me that a fetal-like position is helpful for shielding the robot’s legs and arms.

The company uses reinforcement learning to help fallen robots right themselves. Agility disabled Digit’s obstacle avoidance for the video above to force a fall. In the video, the robot uses its arms to break its fall as much as possible. He then uses the strengthening knowledge he has gained to return to a well-recognized position from which he can stand again by performing an automatic push-up.

One of the foremost benefits of humanoid robots is their ability to integrate into existing workflows – these factories and warehouses are called “brownfields”, meaning they weren’t custom-built with automation in mind. In many existing factory automation cases, errors mean the system effectively shuts down until human intervention occurs.

“Rescuing a humanoid robot won’t be easy,” Playter says, noting that these systems are heavy and may be difficult to arrange manually. “How are you going to do that if he can’t get off the ground?”

If these systems are truly to provide uninterrupted automation, they are going to have to fail and rise quickly.

“Every time Digit goes down, we learn something new,” adds Velagapudi. “When it comes to two-legged robotics, falling is a great teacher.”