The Research Of Control Methods On Vehicle Semi-active Suspension System

With the development of manufacturing industry,various functions and types of vehicles have come out,and suspension system is the key component to ensure the ride comfort and handling stability of vehicle.Semi-active suspension contains adjustable damping device,the effective control strategy can reduce the body vibration by adjusting damping force dynamically,in this way the performance of vehicle vibration can be improved.First,analyzing the vibration source and performance index,and simplifying the suspension as a 2 degree of freedom 1/4 model,the limit band white noise method is used to simulate the actual road,and the pavement and suspension model are established in Simulink.Second,use MR damper as the adjustable damping device,testing and building model for it.The inverse polynomial model can divine control current by the force from control strategy,and the forward corrected Dahl model can obtain the real output force by the motion state and the predicted current.Then,Fuzzy control,PID control and FuzzyPID control are designed for semi-active suspension.The control strategy works with suspension model,pavement model and model of MR damper as a closed loop feedback system,and starts simulation analysis.At the same speed and road conditions,compared with passive suspension,DTL,SWS,ACC under the Fuzzy-PID control are decreased by 13.5%,26.5%,27.2% respectively,which obviously is better than Fuzzy control and PID control strategy,so the Fuzzy-PID is the optimal control strategy.Then,theat the same speed,different road and different speed,same road as the condition,simulate the FuzzyPID control system,further verify its effectiveness.In summary,three semi-active control stategies can improve the vibration reduction performance of the suspension,and the Fuzzy-PID control strategy is the optimal solution.Under the reasonable speed Fuzzy-PID control strategy suspension can adapt to different level of the road,and can ensure the vehicle ride comfort and handling stability effectively.