Robust Adaptive Tracking Control for Uncertain UGV with Controllability Relaxation

This paper provides a robust adaptive trajectory tracking control strategy for uncertain unmanned ground vehicles (UGV) in the presence of external disturbances. A dynamic model of UGV is obtained without assumption of small angle approximation and an affine system of UGV is derived by considering the steering angle as the state variable. By resorting to the existence of some auxiliary matrix, the controllability condition of UGV system is relaxed. Moreover, the outputs track the desired outputs asymptotically and all the signals in the closed loop system are guaranteed to be globally ultimately uniformly bounded. Besides, the proposed strategy is verified via numerical simulations.