Wheel Control Based on Body Configuration for Step-Climbing Vehicle

In our current research, we are developing a holonomic mobile vehicle which is capable of running over the step. This system realizes omni-directional motion on flat floor using special wheels and passes over the step in forward or backward direction using the passive suspension mechanism. This paper proposes a new wheel control method of the vehicle according to its body configuration for passing over the step. The developed vehicle utilizes the passive suspension mechanism connected by two free joints that provide to change the body configuration on the terrain condition. Therefore, it is required to coordinate the suitable rotation velocity of each wheel according to its body configuration. In our previous work, the vehicle motion during step-climbing was discussed and moving velocity of each wheel was derived. In this paper, we adapt these results to wheel control and derived rotation velocity reference of each wheel. The performance of our proposed method is verified by the computer simulations and experiments using our prototype vehicle.