Modeling and µ Synthesis Control for Active Suspension System of Electric Vehicle

In order to improve the vibration suppression ability of in-wheel-motor-driven electric vehicle (IWMD-EV) suspension system, a dynamic model of quarter car active suspension system considering parameter uncertainties and high-order unmodeled dynamics is established by linear fractional transformation (LFT) method. Based on the singular value theory of µ synthesis, a µ-synthesis robust controller was designed for the augmented system of a quarter vehicle active suspension, and the controller was obtained by D-G-K iterative method. The feasibility and effectiveness of the controller are verified by frequency domain and time domain response in Matlab/Simulink environment. The simulation results show that the proposed g-synthesis controller can effectively suppress the vertical vibration of the active suspension system, and improve the ride comfort and handling stability even under the external interference and multi-parameter perturbation.