Walking, legged robots may excel at climbing over obstacles, but wheels are still more efficient for travelling over smooth ground. That's why engineers at ETH Zurich have added powered wheels to their existing ANYmal quadruped robot.
The basic unwheeled version of ANYmal has been around for several years now. Trotting along on its four mechanical legs, it's able to make its way across uneven terrain, and it can even climb stairs. When it comes to simply moving along hallways or sidewalks, though, the robot would use considerably less battery power if it just rolled on wheels.
The new prototype addresses that problem, with four hub motor-equipped wheels that are attached to each of its feet.
It simply zips along on those wheels at speeds of up to 4 meters (13 ft) per second, when in Drive mode. When it has to switch to a walking gait, onboard sensors and a motion-planning microcontroller selectively control the torque in each wheel. This allows some wheels to brake, using their tire to provide grip, while others incrementally roll forwards or backwards as needed.
Although ETH Zurich has been experimenting with wheeled ANYmals since 2018, a new-and-improved version was recently created, and can be seen in action in the video below. The institution also showcased a wheeled walking biped robot earlier this year.
Source: ETH Zurich