Robustness to speed of 4WS vehicles for yaw and lateral dynamics

This paper addresses the issue of robustness and closed loop performance of four wheel steering (4WS) vehicles for yaw and lateral maneuvers for fixed and non-fixed speeds. A feedback structure derived from the plant inverse dynamic, such that the vehicle 2×2 matrix transfer function is robust to speed, is proposed. The efficiency of the proposed structure depends on the actuator's bandwidth and non-linearities, and on the sensor delay. A design example which shows how to implement the proposed algorithm in highly uncertain vehicles, subject to actuator bandwidth limitations and sensor delay, is provided.