No hands, standing on two legs: the ANYmal robot dog solves a 4.6 kg Rubik's Cube

The robot has no hands. It balances on its hind legs and turns the faces of the cube with its front legs.

The cube weighs about 4.6 kg. ANYmal first flips it over with its front legs so that its built-in camera can film every face, then it calculates the solution.

The weight is deliberate. The researchers made the cube heavier so that the face resting on the ground does not move while the robot turns the layers above it.

So that the robot could learn these movements without falling, the team trained it with reinforcement learning. The work is described in a study published as a preprint on arXiv.

The robot made three attempts. Each took between eight and nine minutes, for about 30 moves.