Adjust method of nonlinear gain in four-wheel steering control using Sliding Mode Control

This paper explains a method of four-wheel steering control by using sliding mode control (SMC). The purpose is to improve the control safety of four-wheeled vehicle by using invariable SMC for the cross-wind disturbance that satisfies the matching condition. Influence of the side wind are thought as the cross-wind disturbance related to driving the car. Steering control that corresponds to the influence of the side wind by using SMC is done, and it is examined to be able to do the achievement of the high stability and the decrease of the error margin with the target path. Then, we propose the adjustment method of the value of a nonlinear gain of the control input that considers the phase-lag to the steer of a lateral acceleration. The improvement of the control of the cross-wind disturbance is achieved by the proposal method.