Slip reduction control using plural wheel information for step-climbing vehicle

In our current research, we are developing a holonomic mobile system which is capable of running over the step. This system realizes omni-directional motion on flat floor using special wheels and passes over non-flat ground in forward or backward direction using the passive suspension mechanism. In order to realize the high mobile performance during step climbing, it is required to reduce wheel slippage for maximizing wheel traction. This paper proposes a new plural wheel control method based on wheel slip estimation. Our key idea is estimation of wheel slippage comparing with the loads and rotation velocities of all actuated wheels, and using this result for wheel control of the vehicle for reducing wheel slippage. The controller can adjust control tractions of plural wheels when the wheel begins to slip and can improve the mobile performance of the vehicle. The performance of our proposed control scheme is experimented by computer simulations and experiments.