Mechanism and control of a leg-wheel hybrid mobile robot

This paper describes mechanism and control of leg-wheel hybrid mobile robot. Legged locomotion has high adaptability for rough terrain, and wheeled locomotion possess speed and efficiency. A new locomotion mechanism that combines legs and wheels is proposed, and a prototype mobile robot that adopts the mechanism is introduced. The robot has four legs, and a wheel is attached at the end of each leg. The front leg has three joints and a passive wheel. The rear leg has one joint and an active wheel. In order to make the best of the mechanism, three locomotion modes, wheel mode, hybrid mode, and step mode, are developed. In the wheel mode, four wheels are used on flat terrain. On the rough terrain, the hybrid mode is select, and two legs and two active wheels are used for locomotion. To climb or descend a large step, the step mode is used.