Fault-tolerant tracking control of FW-steering autonomous vehicles

This paper studies the path tracking control of four-wheel steering autonomous vehicles. A robust and adaptive fault-tolerant tracking control strategy is proposed to simultaneously counteract modeling uncertainties, unexpected disturbances, coupling effects, as well as actuator failures. By exploiting a state transformation, together with the introduction of virtual points in the longitudinal centerline of the vehicle, a special feature of the control gain matrix is revealed, which allows for the development of structurally simple and computationally inexpensive robust and adaptive control algorithms. The closed-loop stability issues of the control scheme are analyzed using a Lyapunov-based method. A complex nonlinear dynamic model of a passenger vehicle is developed to simulate the dynamic motion performance and for controller design. The controller is tested and verified via computer simulations in the presence of parametric uncertainties and severe driving conditions.