8. Leg-Wheel Hybrid Mobile Robot
8. Leg-Wheel Hybrid Mobile Robot
A wheel mechanism provides fast and efficient locomotion on flat terrain, while legged locomotion is capable of adapting to a complicated environment. A new locomotion mechanism that has merits of both wheels and legs is being developed. "Walk'n Roll" is a prototype of the new mechanism that combines legs and wheels. Walk'n Roll has four legs, with a wheel attached at the end of each leg. Configuration is different between the front two legs and rear two legs. The front legs have three joints, and a relatively small lockable passive wheel is attached at the end of each. Whereas the rear legs have one joint and a relatively large active wheel attached at the end. There are three locomotion modes, wheel mode, hybrid mode, and step mode. In the wheel mode, four wheels are used for locomotion. The leg motion can be used for steering or the active suspension function. In the hybrid mode, the front two legs are used to walk. The step mode is used when the robot climbs or descends a large step. The rear wheel is moved from the rear side to the front side through the air by leg motion.
