Disney Research, based out of Pittsburgh, have released details of and a short YouTube clip demonstrating their new single legged hopping robot. Currently, the robot can hop for around seventeen seconds – nineteen hops – unassisted before falling over. The robot leg uses a technology that the Disney researchers have quaintly called LEAP, which stands for "Linear Elastic Actuator in Parallel." The robot is being used to experiment and trial new technologies and control mechanisms: legged robots have certain advantages over wheeled robots because they are better able to adapt to uneven terrain, but require a more complicated and sophisticated control mechanism. From a Disney perspective, legged robots are potentially more entertaining as they can move in complex ways, for example they can adapt their gait – although a hopping robot is naturally limited to variants of the given hopping gait!
The project started life as a computer simulation designed to show how the software and balance control could work. Following this, it became a hardware project and technology demonstrator. The leg mechanism is based around a blend of a spring, able to hold most of the weight of the overall robot, combined with similar technology to a speaker designed to provide the movement. The power of the limb depends on magnetic force being applied. This was the most efficient way the researchers found to combine the necessary high performance and control necessary for "safe and robust ground clearance." The leg needs to be powerful, strong but accurately and easily controlled: it has two servos consisting of a hip and is able to hop in different directions. The top of the leg contains the lithium ion batteries, sensors and computer control equipment. The control mechanism is able to finely control the leg by estimating its velocity, based on the onboard sensors, and established control algorithms.
It's not clear the direction that project leads, Zachary Batts, Joohyung Kim and Katsu Yamane, will take the robot next. It is possible that the sensor and control platform will be further refined to extend how long the hopping robot can hop before tipping over. We may also see similar control and actuation technology applied to multi-limbed robots, which could end up as part of Disney's entertainment unit. Perhaps we will see a hopping pirate as part of a new Pirates of the Caribbean ride before too long!