Parameters Matching And Ride Comfort Testing Research Of Electrically Controlled Air-suspension System For Coach

With the improvement of requirement for ride comfort and development of suspension technique,the air suspension has been applied in vehicles increasingly for its unique characters,so the research on air suspension becomes a hot issue.In this paper,the matching among air-suspension parameters and its impact on ride comfort are discussed.Firstly,the characteristics of air-spring'non-linear are analyzed.Based on the theories of Force and Thermodynamics,the stiffness and frequency's calculation formula of the air-spring are conducted,and then the influence on the stiffness and frequency by some parameters are analyzed,too.As a result,the air-suspension's model is built in SIMULINK,and verified by testing of bench.Secondly,the road model and the five freedom model of the half vehicle are conducted by the related knowledge of mathematic and vehicle system dynamics,then their simulation models are built in SIMULINK.The balance positionâ…¡and the absorb damping are chosen according to the result of the simulation.Thirdly,in the paper genetic algorithm is used to get the optimal matching between the stiffness and damping.The body acceleration is chosen as optimal objection,the damping of the front and rear shock absorb as variables and the rate of damping,dynamic flexibility and dynamic load as nonlinear constrains.The optimal results show that they improve the ride comfort and the road holding.Finally,GB/T4970-1996,the bus test in frequency test and ride comfort test in the road.By what was gotten in the test,the RMS of the acceleration in fore-axle,back-axle and the 3-accleration in chair are calculated.After compared to the related standards,it is concluded that the matching is reasonable.