Simple robots that toddle along like an old-fashioned child's toy offer a more realistic and efficient model of human walking than more sophisticated models, researchers said on Thursday. They hope their back-to-basics approach can be used not only to design more efficient robots, but also prosthetics for injured patients and amputees, and to understand better how people walk. The idea is based on "passive-dynamic walkers" -- devices that can walk down a slight slope using only gravity and carefully balanced, pendulum-like legs. These unpowered walkers can produce a surprisingly human-like gait, three separate teams of researchers report in this week's issue of the journal Science. Adding a tiny bit of power, as much as is used by a small fluorescent light bulb, allows an element of control for the walker to make more than a few steps and adjust to differing terrain, including level ground. "We can let the mechanics take care of a lot of the motion as opposed to motors," Andy Ruina of Cornell University in New York, who helped design one of the robot walkers. --More 0101 Local Time 2201 GMT
