with video: Meet MABEL, the fastest robot with 2 knees

Though MABEL runs on two legs and keeps her balance on her own, she's not quite a free sprit. A guide bar attached keeps her running in circles.

U-M engineering professor Jessy Grizzle pronounced MABEL's performance "stunning" in a press release. "I have never seen a machine doing a motion like this."

Researchers imagine some extraordinary possibilities for robots that can walk and run like humans, U-M said.

"If you would like to send in robots to search for people when a house is on fire, it probably needs to be able to go up and down stairs, step over the baby's toys on the floor, and maneuver in an environment where wheels and tracks may not be appropriate," Grizzle said.

MABEL was built in 2008 in collaboration with Jonathan Hurst, who was then a doctoral student at the Robotics Institute at Carnegie Mellon University, U-M said in the press release.

Grizzle and U-M doctoral students Koushil Sreenath and Hae-Won Park have spent the years since ratcheting up MABEL's training. They've been progressively improving the feedback algorithms that enable the robot to keep its balance while reacting to its environment in real time.

MABEL started off walking on even surfaces but eventually learned to clear obstacles like stacked wood.

MABEL is funded by the National Science Foundation and the Defense Advanced Research Projects Agency.