Abstract
This paper develops a reduced-dimension sliding mode controller for steering of a constant speed vehicle. First, a non-linear vehicle is linearized and a 5-dimension state equation consisting of vehicle angle, yaw rate, side slip angle, lateral position, and lateral speed is obtained. A headway viewpoint is introduced to define a lateral error. A 2-dimension sliding mode controller is then derived on a phase plane representing the lateral error and its derivative. Two cases are considered: 1) vehicle parameters are known, and 2) cornering force parameters are unknown. The dimension reduction is justified for the two cases, and the phase plane trajectory is shown to converge to the origin by bounded steering. An important role of a specific headway viewpoint is emphasized for the unknown parameter case. Computer simulations for a non-linear vehicle include a reverse-steering on a packed snow road, and demonstrate a good performance of the proposed controller.
