Disney Research has created what they believe is the world’s first one-legged hopper that does not require a tether to keep from falling and a connection to an external motor or power source. What’s more, the highly-efficient leg modules also can be combined to create multi-legged robots. Pretty cool, right?
The robot itself weighs a little less than five pounds and stands roughly one foot tall. As of now, the robot can maintain its balance for approximately seven seconds, which equates to about 19 hops. However, the Disney researchers anticipate an increase in onboard computing power could keep it upright far longer.
The robot’s single leg uses a technology called a linear elastic actuator in parallel (or LEAP), which employs a voice coil actuator paired with two compression springs. This leg is connected to a torso that contains LiPo batteries, sensors and other electronics.
The leg can move forwards, backwards, right and left using a pair of standard servos that form a hip joint, which handles the angle and real-time adjustments after each hop.
Current and previous single-legged hopping robots are energetically tethered and lack portability. Here, we present the design and control of an untethered, energetically autonomous single-legged hopping robot. The thrust-producing mechanism of the robot’s leg is an actuated prismatic joint, called a linear elastic actuator in parallel (LEAP). The LEAP mechanism comprises a voice coil actuator in parallel with two compression springs, which gives our robot passive compliance. An actuated gimbal hip joint is realized by two standard servomotors. To control the robot, we adapt Raibert’s hopping controller, and find we can maintain balance roughly in place for up to approx. 7 seconds (19 hops) while continuously hopping.
You can see it in action below, and read more here.