Robot based on cartwheeling caterpillars

GoQBot built for speed

View the videos

I, ROLLBOT The crawling robot known as GoQBot can curl into a high-speed wheel (right to left). H.-T. Lin

Inspired by a caterpillar that makes like a wheel and rolls away from predators, researchers have created a robot that curls itself into a loop and peels out at speeds faster than a half meter per second.

Called GoQBot, the 10-centimeter-long robot has a hammer-shaped head and a silicone body embedded with metal coils. The coils contract, musclelike, when pulsed with current, and within 200 milliseconds the crawling bot becomes a wheel and rolls off at impressively high speeds.

Crawling robots typically have many coordinated joints that slow them down, says Satyandra Gupta, director of the Maryland Robotics Center at the University of Maryland in College Park. While good at wriggling through tight spaces, these crawlers plod along in open terrain.

But a crawling robot that turns itself into a wheel can really move. “Once you get into a ball and rolling, you get dramatic increases in speed,” says Gupta, who was not involved in the research. “This is an exciting development.”

Robots similar to GoQBot may someday aid in search and rescue operations that require both crawling through tight, dangerous spaces and moving across flat ground, says Huai-Ti Lin, who created GoQBot as a graduate student at Tufts University in Medford, Mass.

But the GoQBot itself was designed to help researchers better understand the “ballistic rolling” that certain caterpillars display when frightened, Lin says.

“You poke the animal and you don’t know where it’s gone,” says Lin, now at Harvard University. “It’s wicked fast.”

The research, published online April 27 in Bioinspiration & Biomimetics, has already revealed some of the caterpillar’s secrets. Lin and his colleagues initially thought that GoQBot would work best if each of its “muscles” contracted totally independently. But letting the first muscle prime the second by stretching it a little seems to help coordinate body movement, says Lin. “We think that’s probably what’s happening in the caterpillar as well.”  

ROLL WITH ME

Watch the caterpillar that inspired a new robot — and the bot itself — perform ballistic rolling.
Credit: H.-T Lin et al/Bioinspiration & Biomimetics 2011

WHEELIES

The rolling GoQBot in slow motion.
Credit: H.-T Lin et al/Bioinspiration & Biomimetics 2011