Four-Legged Robot Can 'Ninja Walk' Across Narrow Bridges

An engineering team made a four-legged robot 'ninja walk' across a narrow bridge on two legs.
Brad Bergan

A team of engineers created a four-legged robot called HyQ, and it "ninja walks" on two legs across narrow bridges, according to a video published Friday on YouTube.


Four-legged robot's 'ninja walk' with only two legs

Weighing 90 kilograms (198.4 pounds), this "ninja" robot can balance itself on a support line and recover from minor slip-ups and shakes. Using a balance controller, the robot adapts to changes in posture, including varying heights achieved via adjusting the angle of its legs' joints.

To walk across narrow, 6-centimeter (2.3-inch) bridges of up to 1.5 meters (4.9 feet), the robot does a "ninja" walk — using a motion generator to walk the narrow line with fantastic precision.

Robot Ninja Walk
The robot makes precarious steps, two legs at a time. Source: Dynamic Legged Systems Lab / YouTube

New balance controller gives robot ninja skills

At the heart of this futuristic feat is a new balance controller designed for legged robots. It uses point feet, which — since smaller foot areas require more balance to walk without falling — creates serious challenges for not only the robots themselves, but the engineers who have to think their way around a constrained environment with math, metal, and silicon.

"We present a balance controller that has the potential to achieve line walking for quadruped robots. Our initial experiments show the 90-kg robot HyQ balancing on two feet and recovering from external pushes, as well as some changes in posture achieved without losing balance," said a designing Istituto Italiano Di Tecnologia team representative, in a report from the journal IEEE Spectrum.