Why Is This Robot Wearing Sneakers?

Why's that robot wearing sneakers, you ask? Because it has human-like feet.

Researchers at the Georgia Institute of Technology say DURUS, the sneakerbot they created, is the most efficient-walking humanoid ever. Unlike the flat, though sturdy, feet typical of most robots, DURUS' metal feet are shaped like human feet, arched with a ball and heel allowing it to stroll as naturally as possible.

"I think human walking is a really compelling thing. We have complex control algorithms, but the end result is this wonderfully simple behavior," said Aaron Ames, director of the Georgia Tech lab and a professor in the George W. Woodruff School of Mechanical Engineering and School of Electrical and Computer Engineering. Creating a walking humanoid like DURUS entailed a search for simplicity in crafting dynamic movement, he added.

"Our robot is able to take much longer, faster steps than its flat-footed counterparts because it's replicating human locomotion," said Ames. The multi-contact foot behavior also lets researchers get closer to their goal of allowing the robot to walk outside in the real world, rather than only on a treadmill, as it often does in the team's AMBER Lab.

"Most algorithms that robots run on require the basic assumption that the feet are flat. We had to use fundamentally different methods to achieve this type of behavior," said Ames. Instead of having DURUS crunch down in a slow, conservative manner like typical robots, researchers embraced the dynamics of motion to have DURUS strike the heel and roll the foot forward, pushing off on the toe, while maintaining upward posture and grace.

The robot's natural gait also makes it very efficient. The efficiency of robotic locomotion is measured by "cost of transport," or how much power the bot uses divided by its weight and walking speed. The best humanoids are about 3.0, said Ames, but DURUS is 1.4 and self-powered. The robot walks about twice as fast with normal human-like feet and can take much larger steps with more speed and efficiency, said Ames. "The more we can move forward efficiently, the longer [the robot] runs on battery without recharging."

And this efficiency has advantages: In the future, robots who move more like humans can tread upon new terrain they normally wouldn't be able to handle with big boat flat feet. Increased robotic mobility may eventually allow them go where humans can't, said Ames, from space exploration to sand dunes.

Ames also hopes that human-like robotic features can be used to advance technology aimed at helping those with disabilities, in the form of robotic assistive devices like prosthetics and exoskeletons that enable mobility.

While DURUS was created two years ago, in collaboration with SRI International, Ames said, "it's the first step, no pun intended, [in getting robots] to look like us in form, but also to move like us in function."

"I think there's a fascination when we see robots move like us, there's something essential in us that we're creating in these life-like movements," said Ames. "It's exciting to think of what this might become."