Study Of Automobile Active Suspension Control System's Simulation Based On Quarter Of Suspension And Whole Vehicle Virtual Prototype

With the increasing requirement of the vehicle's ride comfort and road security, the design of suspension with good performance has become more and more important. As the conventional passive suspension has the constant spring stiffness and damper coefficient, it can not change with the road disturbances and loads, so it is necessary to design a new-style suspension—active suspension. Active suspension develops with the modern control theory and the electronic technique, its stiffness and damper coefficient can change to adapt the different work circumstances, and it improves the vehicle ride comfort and road holding. So it is significant to research and develop active suspension.The study of active suspension can divide into two aspects:first, the different control laws of 1/4 vehicle active suspension system. In order to get the good performance, the different control laws will be used. At the same time, this thesis makes a deep study and analysis of automobile active suspension control system. Second, because of complexity in vehicle's structure and movement, the thesis analyses the ride comfort of whole vehicle, which is respectively equipped with passive suspension and active suspension.Firstly, this thesis analyze and research some familiar active suspension control algorithm, just as PID, FUZZY, FUZZY self-adapt PID(FAPID). Moreover it lays emphasis on the excellence of the application of the FAPID.Secondly, based on theoretical study, this thesis takes 1/4 vehicle 2 DOF suspension system model as control object to do computer simulation. FUZZY and FAPID control can obviously restrain the vibration of vehicles in terms of different stimulation. Therefore, they are practical and effective.Thirdly, based on the co-simulation method with ADAMS/Car and MATLAB/Simulink, the thesis analyses the ride comfort of whole vehicle, which is respectively equipped with passive suspension and active suspension. Virtual prototype models furnished with controlled suspension are established under the environment of ADAMS. In addition, the controller models of active suspension are set up using MATLAB/Simulink software and simulations are done.The results show the ride comfort of active suspension is better than that of traditional suspension. The co-simulation method, where no complex dynamic equation and transfer function is needed, offers a new approach to control and simulation of complicated mechanism. At the same time, comparing with the conventional means of design, it is much useful to assist designing, adjusting and testing via Virtual Prototype Technology. This means can highly enhance the efficiency of design, decrease the developing periods, cut down the cost of developing products and acquire the optimized integrated performance of the system.