The Study On Optimal Design And Fuzzy Control Of Active Suspension In Vehicles

In the vehicle engineering, the suspension system is the key component to improve the riding comfort and handling stability. Currently, what is widely used in vehicle is passive suspension. The fixed damp parameter in passive suspension can't adjust itself to accord with the complex driving conditions. But the active suspension can do that. It can adjust the control force in time and exactly so as to make the suspension at is best status. So, the analysis of suspension has important significance to the design and research of vehiclesBased on the virtual pattern machinery and advanced control technique, In this dissertation, the dynamic analysis software ADAMS and the MATLAB/Simulik which possessed powerful fuzzy logic function were used as our study tools to carry on the optimal design and vibration analysis of the Independent Macpherson suspension.First, through the analysis of the structure of suspension and the relative location of all parts in suspension and coordinate of suspension in the vehicle, the dynamic model of the suspension in ADAMS/Car was built. Then, with the simulated road signal, the changes of the location parameters of suspension were sutdied, and these parameters were used as our target variables to optimize the suspension model in ADAMS/Insight. By comparison, the optimal solution of the suspension system was got, which will offer a reference to the design of physical pattern machinery.Second, during the whole design process, the control method is the key factor to the control effect. By comparing the performance of all kinds of control methods and considering the non-linear factor of the vehicles, the fuzzy control method which doesn't need the exactly mathematic model was decided to use. Next, through making use of the control box in MATLAB/Simulink, the controller was created according to the control rules which could change the active force to reduce the vertical acceleration.Co-simulation not only exert the dynamic modeling and solution advantage, but also make good use of the advanced control function of MATLAB. Also, it could make the mechanical design system and control design system share the same model of suspension. By comparison, we could see fuzzy control method, this new control method is reasonable and feasible to the control of active suspension system. Compared with passive suspension, it can improve the riding comfort and handling stability.