A Wheel to Leg Transformation Strategy in a Leg-Wheel Transformable Robot

This study focuses on the wheel-to-leg transformation strategy of a leg-wheel transformable robot. The leg-wheel robot capable of fast transformation by 11-linkage mechanism has a leg length 3.4 times longer than its wheel radius. Because the robot in legged mode has fixed relative phases among the legs for locomotion, while the robot in wheeled mode has random phases owing to wheel steering, the transformation takes into account phase regulation. The transformation of a single leg-wheel is designed to minimize energy consumption to enable it to lift its body. The coordination of the leg-wheels during transformation is designed to maintain stability and prevent leg slippage in kinematic constraint. The proposed strategy was simulated and experimentally validated, and the results confirm its functionality.