According to the trajectory tracking control of a car-like mobile robot

a sliding mode tracking control scheme is presented in this paper.An equivalent control law is obtained by using PI-type sliding surface and a switching control law is gotten by replacing sign function by variable rate function.The stability of the system is proved by Lyapunov theory.Simulation results demonstrate that the proposed strategy can not only track any reference trajectories

but also greatly reduce the chattering phenomenon of the system.Even though external disturbances exist

the proposed approach has a satisfactory control quality.