Adaptive Robust Control of Skid Mobile Robot with independent Driving Torque Allocation

Skid-steered mobile robot has been widely used in different fields. In most of existing controllers for skid-steered mobile robots, the wheel velocities are controlled independently to track the desired velocities from the remote manipulation or high level computer. However, this kind of control method may lead to chattering phenomenon of skid steer mobile robots in practice. In this paper, the cause of chattering phenomenon is analyzed. And to solve this problem, a two level adaptive robust control law integrated with torque allocation technique is proposed. In the high level, an adaptive robust control law is developed such that the minimum velocity on the same side track the desired velocity. In the low level, a torque allocation technique is developed for regulating driving torque of each motor. Moreover, a novel control law with consideration of the error of each wheel on the same side is proposed to avoid the spin of wheels when the wheel is lifted from ground. Comparative experiments are carried out to verify the excellent performance of the proposed scheme. The results show that the proposed controller will achieve a good performance and adapt well with the ground condition.