An Innovative Robust Active Rear Steering Vehicle Based on H2/H∞ Control

Considering the design requirements of robustness and stability of active rear-wheel steering (ARS) vehicle system, an H2/H∞ robust controller considering closed-loop regional pole constraints is proposed. The robustness of the system is improved by the fact that the system poles remain in the configured region when the vehicle system parameters, such as vehicle mass, front and rear axle cornering stiffness, and center of mass position are varied. The controller minimizes the effects of modeling errors and external disturbances on the ARS vehicle system, for ensuring the robustness performance of the ARS system. Meanwhile, in order to enhance the ARS vehicle heading stability, the controller is designed to achieve a zero side slip angle. Finally, the effectiveness of the H2/H∞ controller has been validated through simulations. The results confirm that the proposed H2/H∞ robust ARS controller significantly enhances the steering agility at relatively low vehicle velocity and improved handline stability at higher vehicle velocity.