Cubli: motorized reaction-wheel cube that can balance and walk on its edges and corners

A clever combination of motorized reaction wheels, sensors, processors and software allow the 15cm^3 Cubli to balance on its corner or edge, and to stabilize itself in the face of disturbances, or spin on its corner. It can also ramp up its wheel speed, brake them suddenly and use the angular momentum to leap up onto its corner from a flat rest, then fall onto a proscribed side, and leap up -- walking, in other words.

The Cubli is a 15 × 15 × 15 cm cube that can jump up and balance on its corner. Reaction wheels mounted on three faces of the cube rotate at high angular velocities and then brake suddenly, causing the Cubli to jump up. Once the Cubli has almost reached the corner stand up position, controlled motor torques are applied to make it balance on its corner. In addition to balancing, the motor torques can also be used to achieve a controlled fall such that the Cubli can be commanded to fall in any arbitrary direction. Combining these three abilities -- jumping up, balancing, and controlled falling -- the Cubli is able to 'walk'.

The Cubli: a cube that can jump up, balance, and 'walk'