Optimal Four-Wheel Steering Strategy Using Nonlinear Analytical Vehicle Models

This paper presents a systematic methodology and formulation for determining optimal strategies for four-wheel steering of vehicles. The methodology is based on multibody dynamics, design sensitivity, and optimization techniques, and is applicable to a wide variety of mechanical systems. The particular application discussed in this paper considers a vehicle model with four-wheel steering capability, and the presented methodology determines an optimal steering angle ratio strategy for the vehicle. It is shown that such a strategy can improve the ride stability of the vehicle, during a variety of maneuvers, when compared against similar strategies obtained from linearized and simplified vehicle models.