Robust Optimal Control Technology for Four-wheel Steering Vehicle

Establish the two degree of freedom model of four-wheel steering vehicle. A H₂ optimal controller and Kalman filter is designed when the control mathematics model is certainty. Aim at the parameter uncertainty of tire, a four-wheel vehicle steering system uncertain model was founded and analyzed. A H_infin optimal controller is designed with the method of H_infin control theory to solve the problem about model uncertainty. The simulation results show that the controller designed by the proposed method has good robustness, adaptability and stability; it can easily attenuate the model uncertainty and also has the strong ability to resist the disturbance.