Meet FastRunner, a bioinspired robot that thinks it’s an ostrich. It’s also the world’s fastest robotic biped, clocked at 22 mph. Impressive, but no Boston Dynamics Cheetah, at 28.3 mph (on a treadmill) — beating out Usain Bolt’s 27.79 mph.
When an ambulatory robot, such as FastRunner, is moving one of its limbs through free space, its behavior is well-described by a few simple equations. But as soon as it strikes something solid — when a walking robot’s foot hits the ground, or a grasping robot’s hand touches an object — those equations break down.
Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory are hoping to change all that, with a new mathematical framework that could lead to more efficient controllers for a wide range of robotic tasks.
Ordinarily, says MIT professor of associate professor of computer science and engineering Russ Tedrake, a roboticist trying to develop a controller for a bipedal robot would assume that the robot’s foot makes contact with the ground in some prescribed way: say, the heel strikes first; then the forefoot strikes; then the heel lifts.
“That doesn’t work for Fast Runner, because there’s a compliant foot that could hit at any number of points, there’s joint limits in the leg, there’s all kinds of complexity,” Tedrake says.
“If you look at all the possible contact configurations the robot could be in, there’s 4 million of them. And you can’t possibly analyze them all independently.”