Mechanical Analysis And Control Strategy Research Of Automobile Air Suspension System

In recent years,with the rapid development of technology in the automotive field,the comfort during driving is becoming more and more important.The quality of vehicle suspension performance will have an important impact on the ride comfort of the vehicle.In order to improve the comfort of the occupants,air suspension technology is gradually applied to automobile suspension by major automobile manufacturers.In order to study the mechanical properties of air suspension and the influence of control strategies on the performance of the suspension,this paper conducts mechanical tests on a certain type of membrane air spring,and then the air suspension simulation model is designed based on the air suspension mathematical model and the road input model.According to the characteristic analysis of the air suspension,two active controllers are designed,and finally the active control system of the air suspension is simulated and analyzed.The analysis results show that the performance of the active control suspension is better than the passive control suspension,which verifies the effectiveness of the control strategy.The main research contents are as follows:(1)The nonlinear mechanical characteristics of the air suspension system are theoretically analyzed,and a mechanical test of a certain type of air spring is carried out.The test is divided into static and dynamic characteristics tests,and the mechanical characteristics and related parameter.Then the AMEsim simulation model of the air spring is established to verify the accuracy of the test results.(2)The model of the vehicle suspension system is complex,and the air suspension model can be simplified for research.In this paper,the random road surface input model is studied,and the time domain model of the random road surface is established and simulated.Then,based on the mathematical models of air spring and air suspension,the simulation models of air spring,passive suspension and 1/4 air suspension are built,and the indexes for evaluating the performance of air suspension are given.(3)The design of the control system is very important to the suspension system.Because the suspension itself has good nonlinear characteristics,a fuzzy controller and an adaptive fuzzy PID controller are designed in this paper,and a Simulink simulation model of the air suspension based on the two controllers is established.(4)Based on the air suspension simulation model,the designed controller and the suspension model are combined to obtain the model of the active suspension control system.The parameter information of the vehicle and random road surface is input into the Simulink simulation model of active control,and the simulation research in the time domain is carried out.The simulation results show that the proposed two active control strategies can effectively improve the performance of the air suspension compared with the passive control suspension,which verifies the effectiveness of the proposed control strategy.In this paper,the mechanical test of the air suspension is carried out,and it is known that the air suspension has excellent nonlinear mechanical properties.Based on the parameters obtained from the experiment,the air suspension is modeled and simulated.The results show that the control strategy proposed in this paper is feasible in improving the performance of the air suspension,which can provide some references for future research on the air suspension.