| Along with the improvement of ride comfort requirements, the technology of thevehicle suspension is improving in constant development. In this process, theapplication of air suspension on the vehicle is becoming more widespread. Thevehicle with air suspension can reduce the dynamic load of tire, so that the vehiclewill get better ride comfort, driving safety and handling stability. The air suspensioncan also control the height of the car body to increase the driving passing ability. Andunder different road excitation conditions the air suspension has the ability to adjustthe ride height and suspension stiffness to improve vehicle ride comfort. It ispredicted that the air suspension must be one of the mainstream of future suspension.Air suspension in the course of the study, the characteristics of the elastic element-air spring in the air suspension system was studied. Using the knowledge of thepneumatic technology, thermodynamics, fluid mechanics and vibration theory, theelastic model and the inflation/deflation model of the air spring were built. Thestiffness, the frequency characteristics and inflation/deflation properties of air springwere analyzed based on the models. The air spring is a core unit in the air suspensionsystem, its stiffness characteristics of the curve was anti-"S" shape and has a lownatural frequency, these features are beneficial to the air suspension to improve ridecomfort of vehicles. The research on the changing the parameters of the air springimpacting on the overall performance of the whole system is also the focus of thestudy on air spring, and is the key how to match on the vehicle suspension system.In order to study the characteristics of the air spring better, air springcharacteristic test bench was built and the air spring characteristic was test. The curveof nonlinear stiffness characteristics of the air spring got in the test provides a basisfor air spring suspension system on the match.Finally, according to the vehicle’s vibration analysis theory, I created a quartervehicle dynamics model using the Matlab-Simulink software, the two degrees of freedom based quarter vehicle model carried out the vibration analysis. On this basis,the charge from the air springs deflated model starting combined with quarter vehiclesimulation model, the establishment of a quarter the air suspension vehicle simulationmodel. Vehicle ride and the human body vibration response evaluation by simulationtests, the simulation model, compared to using ordinary metal spring suspensionmodel and simulation results of the air suspension model, the application of airsuspension than ordinary hanging the frame has a smaller vehicle vibration and betterride comfort. |
