A robot named MABEL that can walk over rough terrain with a human-like gait has been developed by University of Michigan electrical engineering professor Jessy Grizzle and students.

http://www.youtube.com/watch?v=IlWIWf4daNs
First attempt at walking over rough ground for Bipedal Robot MABEL

Grizzle was surprised that she was able to perform as well as she did. What a robot can step over usually depends on what it can see, but MABEL is blind. She has no camera. The engineers had merely programmed her legs to swing higher to step over or onto obstacles. They hadn’t programmed her specifically to navigate them.

That’s what they’ll do in future, more scientific experiments. The researchers are developing feedback control algorithms to give bipedal robots a strong sense of balance.

This early experiment was, for MABEL, the equivalent of walking confidently down a forest trail while talking to a friend—and not looking down to watch your steps.

So what’s the point of all this? Grizzle says more than 70 percent of the Earth’s land surface isn’t navigable by wheeled or tracked vehicles. Bipedal robots could be capable of traveling in these places.

“If robots are going to perform rescue operations, they’re not going to be walking on a nice linoleum floor,” Grizzle said. “Even if they’re in a building, it’s going to be littered with things that have fallen. They have to be able to walk on an uneven surface without tripping.”

Grizzle’s ultimate goal for MABEL is to make her run. It’s a feat he almost achieved with her predecessor, RABBIT, but RABBIT’s heavy legs carried motors and no springs. MABEL’s motors are in her torso, which leaves her legs light and agile. Her legs also have springs that act like tendons, storing and releasing energy.

“Running would really be one of the highest demonstrations of agile behavior in a machine. It takes such delicate feedback control,” Grizzle said. “RABBIT failed to run in steady state. We got six really beautiful steps, but we never got seven or eight.”

More info: University of Michigan news