Static Output Feedback Control of Vehicle Active Front Steering Considering Multiple Performance Constraints

Abstract

To enable the vehicle to accurately track the ideal yaw rate, thereby improving the vehicle path tracking ability, this paper proposes a static output feedback (SOF) control method for active front steering (AFS) considering multiple performance constraints. Since the cornering stiffness of vehicle tire is a strong nonlinear parameter, the cornering stiffness is taken as the uncertainty parameter of the model. In addition, the two-degree-of-freedom poly-topic model of the vehicle dynamics is established based on the saturated linear tire model to deal with the parameter uncertainty. Moreover, the design of robust SOF controllers with regional pole configuration constraints and H∞ performance constraints are considered for this type of uncertain system. Furthermore, the linear matrix inequality (LMI) sufficient conditions for this type of uncertain system are given, and a coordinate transformation matrix(CTM) optimization method is used to iteratively solve the obtained LMI conditions for the first time. Thus, the robust optimal H∞ SOF controller for this type of uncertain system is obtained. Co-simulation results of MATLAB/Simulink and CarSim show that the designed SOF controller can significantly improve the tracking performance of the desired yaw rate and improve the vehicle path tracking ability. In addition, the controller has a good robustness to the uncertainties of vehicle model parameters.

Keywords

• active front steering (afs)
• static output feedback (sof) control
• poly-topic model
• linear matrix inequality (lmi)
• coordinate transformation matrix