If you say “jump” I say “how high?” – and a new robot from UC Santa Barbara says “over 100 ft (30 m).” The research team says that’s higher than anything else has ever jumped, be it robot or animal, thanks to a unique design that multiplies its stored energy.
The strange robot looks like a toy rocket sitting atop two intersecting bicycle wheels. The “tires” of those wheels are carbon-fiber compression bows, while the spokes are rubber bands extending from a spindle running up the center.
To make the device jump, a motor drives that spindle, pulling a line that stretches the rubber bands and simultaneously compresses the carbon fiber bows. A latch mechanism releases that energy to catapult the robot into the sky.
The UC Santa Barbara researchers say the device can jump higher than 100 ft, which they estimate to be close to the limit possible with currently available materials and technology. It was clocked accelerating from 0 to 60 mph (96.6km/h) in 9 milliseconds, achieving an acceleration force of 315 G.
The researchers say the record-setting robot sprung out of a question they were pondering – what physical limits do jumping robots face, and are they the same as those faced by biological leapers? Most existing jumping robots take design cues from nature, such as grasshoppers, lizards, cockroaches, bush babies, jumping spiders and water striders, but perhaps robots would be better off taking advantage of their own strengths.
The team started by comparing the mechanisms for how animals and insects jump to techniques used by robots. Animals, for instance, have muscles that act as linear motors, meaning they can only store as much potential energy as they can generate in a single stroke. But robots can multiply this energy using motors that can ratchet or rotate several strokes, giving them a huge potential advantage.
“This difference between energy production in biological versus engineered jumpers means that the two should have very different designs to maximize jump height,” said Charles Xiao, an author of the study. “Animals should have a small spring – only enough to store the relatively small amount of energy produced by their single muscle stroke – and a large muscle mass. In contrast, engineered jumpers should have as large a spring as possible and a tiny motor.”
With this in mind, the researchers designed their robot to have a spring-to-motor ratio almost 100 times larger than that of jumping animals, which is what allowed it to reach such heights. This kind of locomotion could be particularly useful for space exploration – the lower gravity of the Moon or Mars could allow robots to leap higher and farther more efficiently than here on Earth. The team calculated, for instance, that on the Moon this robot should be able to jump higher than 410 ft (125 m) and travel 1,640 ft (500 m) horizontally.
The research was published in the journal Nature. The robot can be seen in action in the video below.
Source: UCSB