Roly Poly Caterpillar Robots Can Hit Turbo Boost
Speedy robots shaped like wheels have trouble fitting into tight spaces, but worm-like robots that inch along can't hit the turbo boost. Now a prototype caterpillar robot can curl up and roll along when speed is of the essence.
The robot imitates real caterpillars that can tuck in and quickly wheel away from predators in a process called ballistic rolling. That reconfiguration could give future robots the flexibility to do urban rescue, building inspection and environmental monitoring especially in the wake of disasters .
"Due to the increased speed and range, limbless crawling robots with ballistic rolling capability could be deployed more generally at a disaster site such as a tsunami aftermath ," said Haui-Ti Lin, a bioengineer at Tufts University. "The robot can wheel to a debris field and wiggle into the danger for us."
Lin and his colleagues created a 4-inch (10-cm) soft-bodied robot, called GoQBot, based on silicone rubber. The robot uses shape memory alloy coils to curl up in less than a tenth of a second and roll away at more than 1.6 feet per second (0.5 m/s).
A high speed 3-D system tracked the motion of the GoQBot based on five infrared emitters along its side, and a force plate measured the strength with which the robot pushed off into its ballistic roll.
The ballistic rolling way of travel remains unpractical for current generation robots, because it needs smooth surfaces, a lot of power and often takes the robot to an unpredictable stopping point. Most practical robots in use today use wheels, even if a few have tested legs for walking . One robot even transforms legs into wheels .
Still, playing with the idea of flexible rolling robot could someday lead to robots not unlike the laser-toting droidekas of the "Star Wars" prequels. Those films may not have lived up to the original "Star Wars" series, but at least their robots may have had a practical leg up over the locomotion of lumbering AT-AT walkers in "The Empire Strikes Back."
Details on the robot appear in the April 26 issue of the journal Bioinspiration & Biomimetics.