Ranger Robot Runs 45 Laps At Cornell - Sets Record

We're not sure what kind of batteries it was using, but the Cornell Ranger robot just kept going and going April 3 when it set an unofficial world record by walking nonstop for 45 laps - a little over 9 kilometers or 5.6 miles - around the Barton Hall running track.

Developed by a group students working with Andy Ruina, Cornell professor of theoretical and applied mechanics, the robot walked (and walked) until it finally stopped and fell backward, perhaps because its battery ran down. "We need to do some careful analysis to find out for sure," said Greg Stiesberg, a graduate student on the team.

An earlier version of the robot had already set a record by free-walking a bit over 1 kilometer, about .62 miles. (Another robot has walked 2.5 kilometers [1.55 miles] on a treadmill, Ruina noted. A six-legged robot has walked a bit more than 2 kilometers, and there's some debate over whether or not that counts.)

There are no rules for such records, Ruina admits, and the Guinness people were not involved. "There's a lot of rigmarole with that," he explained. The event, he said, was to show off the machine's energy efficiency. Unlike other walking robots that use motors to control every movement, the Ranger emulates human walking, using gravity to help swing its legs forward.

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