Researchers build first tetherless hopping robot

October 6, 2016, Disney Research
Credit: Disney Research

One-legged hopping robots have long been used to study balance issues, but their dependence on off-board power has kept them tethered, literally, to the lab. Now, Disney Research has figured out how to build a hopper that runs on battery power.

The researchers believe theirs is the first one-legged hopper that does not require a connection to an external motor or power source.

Though one-legged robots can only move by hopping, freeing them of tethers would open up new, non-research uses, said Joohyung Kim, associate research scientist at Disney Research. The highly efficient leg modules also can be combined to create multi-legged robots.

By concentrating on building a light, efficient , Kim and his collaborators, Katsu Yamane and Zachary Batts, developed a robot weighing a little less than five pounds and about one foot in height. As of now, the robot can maintain its balance for approximately seven seconds, or 19 hops, but the researchers anticipate an increase in on-board computing power could keep it upright far longer.

The researchers will present their tetherless hopper at the International Symposium of Experimental Robotics, ISER 2016, in Tokyo, Japan, Oct. 3-6.

Many hoppers have been hydraulic devices. But hydraulic actuation requires off-board motors and is energetic enough to pose issues outside of a controlled laboratory environment, Yamane said.

To achieve the high-speed, high-force actuation necessary to make the robot hop using electrical power, the researchers designed a linear elastic actuator in parallel, or LEAP, to serve as the leg. The LEAP uses a voice coil actuator - a highly efficient actuator that operates the same way as a loudspeaker driver - paired with two compression springs.

This leg is connected to a torso that contains , sensors and other electronics. To keep this upper torso level during hopping, the angle of the leg is adjusted at each hop using two standard servo motors. The torso is only about twice as heavy as the leg, whereas most hoppers have torsos that are much heavier in relation to the leg, which helps them achieve dynamic balance.

Explore further: Researchers develop two-legged robot that walks like an animated character

More information: "Untethered One-Legged Hopping in 3D Using Linear Elastic Actuator in Parallel (LEAP)-Paper" [PDF, 11.50 MB]

Related Stories

Genoa lab makes sure robot can stand up to hard knocks

December 30, 2015

HyQ2 is a quadruped that has been in high focus at the Italian Institute of Technology's Dynamic Legged Systems lab. They have been getting it disaster-ready for search and rescue missions and for environment disasters.

Two-legged robot able to run without ZMP control (w/ Video)

September 3, 2014

( —A team of researchers at the University of Tokyo has built a small two-legged robot (named Achires) capable of running without using Zero Moment Control (ZMP)—instead it relies on high speed cameras and actuators. ...

Kondo Robot releases a hexapod robot kit (w/ video)

April 11, 2011

( -- Kondo Robot, a Japan-based robotics company known for selling robotics kits which often end up in robot-on-robot battles, announced the release of a new robot kit. The kit, named the KMR-M6 is a Hexapod Robot, ...

Recommended for you

1 in 3 Michigan workers tested opened fake 'phishing' email

March 16, 2018

Michigan auditors who conducted a fake "phishing" attack on 5,000 randomly selected state employees said Friday that nearly one-third opened the email, a quarter clicked on the link and almost one-fifth entered their user ...

World's biggest battery in Australia to trump Musk's

March 16, 2018

British billionaire businessman Sanjeev Gupta will built the world's biggest battery in South Australia, officials said Friday, overtaking US star entrepreneur Elon Musk's project in the same state last year.

Origami-inspired self-locking foldable robotic arm

March 15, 2018

A research team of Seoul National University led by Professor Kyu-Jin Cho has developed an origami-inspired robotic arm that is foldable, self-assembling and also highly-rigid. (The researchers include Suk-Jun Kim, Dae-Young ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.