U.S. researchers said Tuesday they have designed a small galago-inspired robot with the highest robotic vertical jumping agility ever recorded.
The robot, known as saltatorial locomotion on terrain obstacles, or Salto, can leap into the air and then hit a wall to make a second jump or perform multiple vertical jumps in a row, according to the study published in the debut edition of the U.S. journal Science Robotics.
Salto weighs 100 grams, is 26 centimeters tall when fully extended, and can jump up to one meter. Scientists hoped it can one day be used to jump around rubble in search and rescue missions.
To build the robot, researchers at the University of California (UC) Berkeley studied the animal kingdom's most vertically agile creature, the galago, which can jump five times in just four seconds to gain a combined height of 8.5 meters.
The galago has a special ability to store energy in its tendons, a phenomenon called "power modulation," so that it can jump to heights not achievable by its muscles alone.
The researchers adapted this process to Salto, offering its single leg a mechanical advantage that allows the leg's motor to store energy in a spring at the beginning of the jump and then release it at a higher power during subsequent motion.
Then, they measured Salto's power modulation with a new metric they devised called "vertical jumping agility," which is defined as the ratio of the maximum jump height to the time it takes to complete one jump.
Salto was able to jump to a height of one meter in 0.58 seconds, indicating it has a vertical jumping ability of 1.75 meters per second, which is higher than the vertical jumping agility of a bullfrog (1.71 meters per second) but short of the vertical jumping agility of the galago (2.24).
"We don't quite reach the galago's performance, but Salto has 56 percent more vertical jumping agility than any other untethered robot," Duncan Haldane, a robotics Ph.D. candidate at UC Berkeley, who led the work, said at a teleconference with reporters.
This vertical jumping agility made wall jumping possible, where Salto jumps from the floor, flips forward and then kicks off the wall to attain an average height gain of approximately 1.21 meters.
However, other robots can jump higher than Salto in a single leap. For example, TAUB, a locust-inspired jumping robot, can leap to 3.2 meters in a single jump.
"These windup robots wind up for a few minutes on the ground and then can jump to like a little over three meters," said Haldane. "So we're not the highest, but if you look at our vertical jumping agility of untethered robots, we have the highest (agility) there."
"Our goal was to have a search and rescue robot small enough to not disturb the rubble further, and to move quickly across the many kinds of rubble produced by collapsed buildings," he said.
The robot itself will not drag someone out of a collapsed building, but can be used to carry sensors capable of detecting a trapped person, they explained.