A robot with four legs solved a giant Rubik’s Cube using only its feet. Researchers at ETH Zurich and NVIDIA reported the work. The robot, called ANYmal-D, finished the puzzle three times on its own. Each time took about 30 steps and eight to nine minutes.
First, the robot walks around the cube and tips it over to see every side. Its camera reads the colors, and a computer program finds a way to solve the puzzle. Another program turns that plan into foot movements. The camera checks the cube’s position between moves.
The robot tips the cube toward or away from its body. For one move, its right foot holds the cube still. Its left foot turns the top two rows of blocks. The other rows must stay in place.
The robot learned these skills in a computer-made world. It earned points for good moves and for keeping its balance. In tests, it handled slippery floors and stone paths, and it recovered after a stick pushed the cube or a rope pulled its leg. The team says this shows how a robot can finish a long task without extra arms or tools for holding things.
