ETH robot can balance with just a single reaction wheel

At the Swiss Federal Institute of Technology in Zurich (ETH), an innovative robot has been built that can balance on its pivot with just a single reaction wheel, further details of which can be found in a press release. Moreover, it is also capable of compensating for external disturbances. This innovative inverted 3D pendulum dubbed the “One-Wheel Cubli” has now been presented in the most recent edition of the journal “Mechatronics”.

The One-Wheel Cubli is a further development of the Cubli robot cube, which caused a stir ten years ago because it could balance on a pivot by itself. For this, the robot required several reaction wheels in its interior. It was developed by a group of researchers headed up by ETH robotics professor Raffaello D’Andrea. The same workshop is now behind this latest development.

As ETH Zurich explains in a video, the One-Wheel Cubli has a balancing pole like a tightrope walker. The inertias of the system differ significantly in their two directions of motion. “The consequence is a time-scale separation of the underlying tilt dynamics, which renders the system controllable”, the three authors write in the abstract to their work. In this way, the innovative robot is able to stabilize both directions simultaneously, but requires just a single reaction wheel to perform this balancing act. mm