Study On Control Method Of Automotive Semi-active Suspension System Based On MR Damper

The semi-active suspension is main research aspect of automobile suspension engineering, because of its performance is close to active suspension, its manufacture and useful cost is under active suspension. After finishing development of MR damper, to study control arithmetic is main problem. At present, the control arithmetic of semi-active suspension is skyhook damping control and fuzzy control. Although the skyhook damping control provides good ride quality improvement, it does not provide adequate damping in the wheel hop frequency; the dynamic tyre force is increased. Fuzzy logic control arithmetic has well robust but has bigger steady error. So, three are some problems to study for semi-active suspension, they are system control strategy and automobile vehicle vibrating control with semi-active suspension and control system performance. In this paper, the methods of theoretical analysis, numerical simulation and road testing are applied to study system modeling and control method of semi-active suspension system based on MR damper. The Natural Science Foundation of China financially supported the research project.Firstly, the automobile vibrating system dynamic model and simple damping force model are given in this paper. The model parameter is getting by the method of CAD/CAE and testing and force calculating. The measuring device named double spring inversion pendulum is designed based on the mass-period method. With vibrating signal test apparatus and clamps, the mass parameters testing system is constituted. The effect of nonlinear on measuring device is amended with period formula. The mass parameter of parts of engine-box and automobile-doors and automobile-chairs is measuring with double spring inversion pendulum, the suspension system and tire's damp and stiff numerical value is provided by testing. The mass parameter of automobile body is getting by CAD/CAE. The parallel forces of parts of automobile are constituted. The mass parameter of sprung mass and unsprung mass is calculated. So, the mass parameters and geometrical parameters and mechanical parameters of 2DOF/7DOF automobile vibrating system are obtained by combining testing with CAD/CAE modeling with calculating. The dynamics differential equation of 2DOF/7DOF automobile vibrating system motion is derived using Lagrange equation. The state space model for 2DOF/7DOF automobile vibrating system is constructed by system state space describing method.