One-Legged Jumping Robot Shows That Control Is Everything

Robots that can jump have been seen before, but a robot that jumps all the time is a little different. Salto-1P is a one-legged jumping robot at UC Berkeley, and back in 2017 it demonstrated the ability to hop continuously with enough control to keep itself balanced. Since then it has been taught some new tricks; having moved beyond basic stability it can now jump around and upon things with an impressive degree of control.

Key to doing this is the ability to plant its single foot exactly where it wants, which allows for more complex behaviors such as hopping onto and across different objects. [Justin Yim] shows this off in the video embedded below, which demonstrates the Salto-1P bouncing around in a remarkably controlled fashion, even on non-ideal things like canted surfaces. Two small propellers allow the robot to twist in midair, but all the motive force comes from the single leg.

Part of the challenge lies in the fact that the only opportunity to exert any real control over the robot’s next move is in the tiny slice of time during which the foot actually touches the ground. After that, it’s just physics playing out whatever got set up. Much of the work for movement planning is done with the help of motion capture, but researchers are working on improving things even more, and moving away from the need for such external dependencies.

If a machine doesn’t need to control where it goes, it could even get away with a single motor and no sensors like Runner does. We’ve even seen a wheeled robot prove that jumping doesn’t need legs.