| Automotive suspension performances directly affect the ride comfort and the stability of the vehicles. Nowadays, the widely used suspension system is belong the passive control system. But, with the fixed system parameters, the traditional passive suspension is impossible to meet expected demands of the vehicle in various conditions. Therefore, in recent years, the active suspension is utilized to improve the suspension's performance. The active suspension can adjust the control force actively and timely to reduce the vibration according to the working condition. So it can achieve the purpose of improving ride comfort and handling stability simultaneously.This paper presents a new efficient method for controlling active suspension systems. The approach used is a fuzzy scheme which offers new opportunities in the improvement of vehicle ride performance. This fuzzy scheme is fit to this kind of automotive suspension system, which works in the time-variability parameters, the nonlinearities and in various conditions. Simulation results of an active suspension system based on PID control theory are compared with the performance of active systems with fuzzy control.In this paper, based on the vehicle dynamics theory, a dynamic model of active suspension is constructed. The mathematical and simulating model of road surface irregularity of B and D grade are also established, which is the model of integral white noise. Three performance indexes: acceleration of vehicle body, dynamic flexibility of suspension and dynamic load of tyre are evaluated, and the automotive suspension system has been simulated by means of the software Matlab/Simulink. As a result, dynamic response in time domain can be obtained. The simulation results show the performance of the two active suspension systems.Simulation results indicate that the fuzzy logic control system improves the performance indexes of the acceleration of vehicle body, dynamic flexibility of suspension and dynamic load of tyre. The fuzzy logic control strategy is more reasonable and feasible than other control strategies. The statistical results indicate that fuzzy logic control method has fairly good robustness and is more fit to the automotive suspension that is a non-linear and time-variable system.The efficient method that this paper presents offers a new idea to the field of research on suspension control strategies. And in this paper, some theoretic and numerical value reference is given for guiding experimental research and development of vehicle active suspension.
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