December 11, 2008

Grasshopper-Inspired Robot Rolls, Jumps

A grasshopper served as the inspiration for a new robot that has the ability to leap and roll, allowing for better mobility over obstacles.

Designed by Rhodri Armour, a Ph. D. student at the University of Bath, the robot mimics the way grasshoppers store kinetic energy and release it at once in a quick burst that enables them to achieve high jumps.

Jollbot is spherical, which allows it to roll in any direction without the need for wheels. Its spherical design also eliminates the possibility of being flipped over or getting stuck in potholes.

"Others in the past have made robots that jump and robots that roll; but we've made the first robot that can do both," said Armour.

"In nature there are two main types of jumping: hopping, like a kangaroo, which uses its fine control and direct muscle action to propel it along; and "Ëœpause and leap', such as in a grasshopper, which stores muscle energy in spring-like elements and rapidly releases it to make the jump."

The Jollbot weighs less than two pounds, meaning it won't get damaged easily after high jumps and is therefore less expensive than other conventional exploration robots.

Armour and colleagues hope the new robot will open new opportunities for exploration of various terrains throughout space.

By squashing itself down low to the ground, Jollbot prepares itself to jump by storing up kinetic energy in the same fashion as a grasshopper.

Once the energy is released, the robot can thrust itself almost 20 inches into the air, Armour said.

Armour, who has just submitted his PhD thesis, took measurements using a high-speed camera to analyze how the robot jumped and to predict how it might behave in a low-gravity environment, such as in space.

The prototype is currently powered by electric motors, but researchers hope to incorporate a layer of solar cells to its exterior that could allow Jollbot to power itself while in space.


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