Asymptotic tracking control of 4WS vehicles based on virtual points

This paper considers the lateral and longitudinal path tracking control of four-wheel steering vehicles. By introducing the virtual points, a robust adaptive path tracking control strategy is proposed to simultaneously counteract modeling uncertainties, unexpected disturbances, and coupling effects. An adaptive model-based feedforward adaptive term and the robust integral of the sign of the error (RISE) feedback term are used to yield an asymptotic tracking result, which improve the tracking performance and reduce the control effort. The stability of closed-loop system is analyzed using a Lyapunov method. Simulation results are included to illustrate the proposed control scheme.