A four-legged robot has solved a giant Rubik’s Cube using its feet alone, researchers at ETH Zurich and NVIDIA report. The ANYmal-D completed the puzzle independently three times. Each solution took about 30 steps and eight to nine minutes.
The robot first walks around the cube and flips it to inspect every side with its camera. After software identifies the colours and calculates a solution, a planning programme converts it into physical movements. Between moves, the camera updates the cube’s position so the robot can place its feet correctly.
Its skills include flipping the cube and turning its layers. For a layer turn, one foot holds the cube steady while the other turns it; unwanted movement in the remaining layers would spoil the solution. The team taught these skills in a computer simulation, where successful movements and good balance earned virtual rewards.
Tests included slippery floors, stone paving and stones covered in moss. Researchers also pulled the robot’s leg with a rope and pushed the cube away, but it recovered from these disturbances. Its flipping skills worked on a small, light box and a cylindrical container too.
