Fuzzy control and simulation of a new semi-active suspension

On the base of a four degree-of-freedom semi-active suspension with variable stiffness and damping and fuzzy control theory, a common fuzzy control system and a variable universe fuzzy control system were designed. The models of the passive suspension and the semi-active suspension with two fuzzy control systems were simulated with integral white noise random input in Matlab/simulink. The result of the simulation shows that, compared with the passive suspension, the vehicle´s vertical acceleration and pitch angular acceleration of the semi-active suspension with variable stiffness and damping are effectively reduced, and reaches the purpose of improving the ride comfort. And the variable universe fuzzy control system is better than the common fuzzy control system on decreasing vibration.