Steering Vector Control for Lateral Force Distribution of Electric Vehicles

This paper proposes a control configuration for electric vehicles (EVs) with four-wheel independent steering (4WIS) motors which is named “steering vector control” (SVC) strategy. The SVC architecture is hierarchically presented by three layers. The upper layer determines the total lateral force and the total yaw moment based on the control of sideslip angle and yaw rate. The middle layer determines optimum tire lateral force distribution depending on the total tire workload. In the lower layer, lateral forces are controlled by a two-degrees-of-freedom (2DOF) controller (feedforward and feedback). The modeling and control organization of the studied vehicle are presented by using energetic macroscopic representation (EMR). Simulation tests show that SVC can improve the lateral stability and reduce the total workload by 6% in comparison with the traditional feedforward force distribution approaches.