Research Of Control Methods And Co-simulations Study On The Vehicle’s Semi-active Suspension

As an essential vehicle assembly, the suspension system has a great effect on the riding comfort and handling stability performance of vehicle. Compared with the traditional passive suspension, the semi-active suspension can control the vehicle vibration effectively and improve the vehicles’ comprehensive performance by adjusting the damping force of the damper, after the road excitation and the vehicle motion state are measured by using sensors. Meanwhile, the semi-active suspension has the advantages of simple structure, less cost and low energy consumption.In this paper, 1/4 vehicle model based on semi-active suspension is token as the research object, and some control strategies for semi-active suspension are investigated. Con-simulations under ADAMS and MATLAB, with the use of the different control strategies, are carried out, and the performances of the control plans are compared. The content of this paper mainly includes:(1)The dynamic models of vehicle vibration system are built, and suspension performance evaluation indexes are introduced, as well as the characters of virtual prototype simulation analysis software of ADAMS. The mechanical model based on semi-active suspension by using ADAMS is built, and the vehicle mechanical model is analyzed through defining the testing functions.(2)The excitation of the vehicle vibration is analyzed, and the sinusoidal model and the random model of the road input are built. The road surface roughness as well as its power spectrum is studied. The spring-damper model of the semi-active suspension is built by using ADAMS. After the input and output state variables of the model are defined, the co-simulation platform under ADAMS and MATLAB is built.(3)The basic theories of PID control strategy are introduced. Genetic algorithm(GA) is used to optimize the parameters of PID controller. The GA-PID control strategy for semi-active suspension is studied, in which the dynamic performance of GA-PID controller is analyzed. The co-simulations of the passive susprnsion and the semi-active suspension based on PID and GA-PID control strategy are studied, using the co-simulation plantform. The co-simulation results show that the performance of the semi-active suspension based on GA-PID control strategy is better than that of the passive susprnsion, and that based on PID control strategy.(4)The basic theories of fuzzy control are introduced. The fuzzy control strategy is used to refine the parameters of GA-PID controller. The fuzzy GA-PID control strategy of semi-active suspension is studied, and the dynamic performance of it is analyzed. The performances of the passive suspension and the semi-active suspension based on PID, GA-PID and fuzzy GA-PID control strategy are studied by using the co-simulation plantform. The co-simulation results show that the performance of the semi-active suspension based on fuzzy GA-PID control strategy is better than that of the semi-active suspension based on GA-PID control strategy.