ETH Zurich ANYmal robot solves giant Rubik's Cube using feet

Researchers at ETH Zurich’s Robotic Systems Lab have demonstrated that the ANYmal-D, a four-legged inspection robot, can autonomously solve a giant Rubik’s Cube. The feat relies on a technique called “pedipulation,” where the robot manipulates objects using its feet rather than hands.

To complete the task, the robot uses an onboard depth camera to map the colors on all six faces of the cube. It then utilizes a combination of classical algorithms, computer vision, and reinforcement learning to plan and execute the necessary rotations. Because the cube weighs approximately 10 pounds (4.6 kg), the robot must maintain precise balance and apply specific torque to rotate individual layers without accidentally shifting others or tipping over.

The process involves the robot walking around the freestanding cube to reorient it, using its feet to grasp edges and roll the object onto new faces. To rotate a layer, the robot must plant one foot firmly to stabilize the base while using another foot to pull the target layer through a quarter turn.