But researchers at Cornell University, the Massachusetts Institute of Technology (MIT) and Holland's Delft University of Technology have built robots that seem to more closely mimic the human gait -- and the Cornell robot matches human efficiency. The researchers' inspiration: simple walking toys that fascinated children in the 19th century.
"Already our robot seems to be at least 10 times more efficient than anybody else's," says Andy Ruina, Cornell professor of theoretical and applied mechanics. The Cornell robot consumes an amount of energy per unit weight and distance comparable to a human walker. In contrast, they estimate that the Honda Asimo uses at least 10 times as much energy as a human. The MIT and Delft robots, though not built deliberately to be energy-efficient, also use much less energy than the Asimo. More important, the researchers say, is that their robots provide a more realistic model of how humans walk.
Ruina, his former student Steven Collins, MIT postdoctoral researcher Russ Tedrake and Delft postdoctoral researcher Martijn Wisse describe their new robots in the latest issue of the journal Science (Feb. 18, 2005). They are presenting a press briefing on their work at 10 a.m. today (Feb. 17) at the annual meeting of the American Association for the Advancement of Science in Washington, D.C.
Cornell's robot equals human efficiency, Ruina explains, because it uses energy only to push off, while other robots needlessly use energy to absorb work, for example in moving the limbs forward more slowly than they would naturally swing under gravity power. "In other robots the motors are fighting themselves," he says.