Researchers at Disney Research have invented a one-legged hopping robot that can bounce 19 times without falling over.

The project which is lead by Zachary Batts, Jooyung Kim, and Katsu Yamane started off as a computer simulation and ended as a hardware product.

The robot’s single leg uses a technology called a linear elastic actuator in parallel or LEAP. The robot can jump for about seconds before toppling - or about as long as Tigger can hop on his tail before he crashes into something.

The researchers wrote “The LEAP mechanism comprises a voice coil actuator in parallel with two compression springs, which gives our robot passive compliance. An actuated gimbal hip join is realized by two standard servomotors." 

The researchers also found that single-legged robots make the best entertainment. “Legged robots are useful because, among other advantages, they can overcome uneven terrain, and can entertain an audience as they act out complex movements (e.g. different gaits),” they wrote. “Single-legged robots have the simplest topology in the class of legged systems, and are limited to a hopping gait. Not only do single legged hopping robots provide a simplified testbed for locomotion control algorithms, they also demand high-speed, high-force actuation to achieve safe and robust ground-clearance and subject the actuator to greater mechanical stresses than do multi-legged systems. For these reasons, single-legged hopping robots provide an ideal benchmark for actuators used in legged locomotion.”