Video: Walking robot navigates bumpy ground

ANN ARBOR, Mich.—A robot named MABEL with a human-like gait can walk over rough terrain in University of Michigan electrical engineering professor Jessy Grizzle's lab. Grizzle and his students Hae-Won Park and Koushil Sreenath posted a YouTube video of MABEL's first steps over wooden planks, and within five days it was viewed more than 84,000 times. (Spoiler alert!) It doesn't have a happy ending. MABEL breaks a leg and doubles over, but not before she clears planks stacked to 2.5 inches high. "In the video, MABEL falls, but does not trip," Grizzle said. "Each shin has a built-in mechanical fuse that gives way when the load on the leg exceeds a threshold. This is done to avoid damage to the bearings in the hips.