| Great importance of modern car vehicle suspension is getting higher and higher,the suspension system on the one hand delivers the force or torque of the road acting onthe tires to the frame or body of the vehicle efficiently, which ensure the normaloperation of the vehicle; on the other hand the suspension system absorbs the road’undulation and reduces body vibration in order to ensure the smoothness of the vehicle.Most of the vehicles use the passive suspension system now, which’s system parametersfixed at design time, can only compromise the operation of the vehicle stability and ridethrough the line, but can not meet the requirements of the majority of conditions. Activesuspension system’s parameters can change according to the actual situation and adjustthe suspension control to meet the requirements of the working conditions, so that thesuspension system can work in good condition.This paper first analyzes the basic characteristics of the vehicle, suspensionevaluation method of ride comfort, suspension system and modeling assumptions toestablish the model of passive suspension and active suspension dynamics. take therandom road surface and speed as the input of the suspension system and get suspensionsystem dynamics equation and state equation for active suspension system controlgroundwork.Secondly, take the fuzzy control theory on in front of active suspension system;establish the fuzzy domain, quantitative parameters and the fuzzy control rules. On thebasis of the analysis of PID control principle and characteristic, the fuzzy PID associatesPID control with the fuzzy control, absorb the control strategies of advantages. Take thefuzzy PID control strategy in the active suspension system as real.Thirdly, in MATLAB, the PID control suspension, suspension of fuzzy controland fuzzy PID control suspension are established; select the body vertical accelerationas the object to analysis the system dynamic performance and robustness of theparameter uncertainty on a variety of control strategy.Finally, establish the1/4vehicle passive suspension model and active suspensionmodel and use the white noise form of grade B road as a suspension system input baseon the analysis of suspension system. The simulation shows that the PID controlsuspension performance was significantly better than the traditional passive suspension;fuzzy control suspension in the body vertical acceleration control effect is better than PID control, but the suspension dynamic interference degree worse than the PID control;and fuzzy PID control in the body acceleration and suspension dynamic interference ofthe two performance indicators are better than the other two control strategies. |
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