Elastic robot jumps higher than any other robot or animal
If you say “jump”, I say “how high?” – and a new robot from UC Santa Barbara says “more than 100 feet (30 m)”. The research team says it’s more than anything that’s ever jumped, whether robot or animal, thanks to a unique design that multiplies its stored energy.
The strange robot looks like a toy rocket sitting on two crossing bicycle wheels. The “tyres” on these wheels are carbon fiber compression arches, while the spokes are rubber bands extending from an axle that rises in the center.
To blast the device, a motor drives this spindle, pulling a line that simultaneously stretches the rubber bands and compresses the carbon fiber arcs. A locking mechanism releases this energy to catapult the robot into the sky.
The UC Santa Barbara researchers say the device can jump higher than 100 feet, which they believe is close to the limit possible with currently available materials and technology. It was timed to accelerate from 0 to 60 mph (96.6 km/h) in 9 meters per second, reaching an acceleration force of 315 G.
The researchers say the record robot was born out of a question they asked themselves: what physical limitations do jumping robots face, and are they the same as those faced by biological jumpers? Most existing jumping robots take design cues from nature, such as grasshoppers, lizards, cockroaches, bush babies, jumping spiders and water striders, but maybe robots would do better to leverage their own strengths.
The team started by comparing the jumping mechanisms of animals and insects to the techniques used by robots. Animals, for example, have muscles that act like linear motors, meaning they can only store the amount of potential energy they can generate in a single stroke. But robots can multiply that energy by using motors that can rattle or spin multiple shots, giving them a huge potential advantage.
“This difference between energy production in biological jumpers and technical jumpers means that the two would have to have very different designs to maximize jump height,” said study author Charles Xiao. “Animals should have a small spring – just enough to store the relatively small amount of energy produced by their muscle movement alone – and a large muscle mass. In contrast, technical jumpers should have as large a spring as possible and a motor tiny.
With this in mind, the researchers designed their robot to have a spring-to-motor ratio nearly 100 times that of jumping animals, allowing it to reach such heights. This type of locomotion could be particularly useful for space exploration – the weaker gravity of the Moon or Mars could allow robots to jump higher and further more efficiently than here on Earth. The team calculated, for example, that on the Moon this robot should be able to jump more than 410 feet (125 m) and travel 1,640 feet (500 m) horizontally.
The research was published in the journal Nature.