Sliding-mode trajectory-tracking control for a four-wheel-steering vehicle

Trajectory-tracking is an important behaviour for mobile robots. This paper addresses the nonlinear sliding-mode trajectory-tracking control problem for a four-wheel-steering vehicle (4WS). The advantage of this controller over current control procedure is that it is applicable to a large class of vehicles with single or double steering and to a tracking velocity that is not necessarily constant. The effectiveness of the proposed control law to trajectory-tracking control is demonstrated by simulation results.