Dynamics Simulation And Research On Active Control Of Air Suspension Bus

The air suspension system is a kind of active suspension system, which in theactive control action can reduce vibration of the vehicle, decrease the suspensiondeflections, reduce the displacement of wheels, improve the ride comfort and alsoeffectively protect the road surface. With the air suspension system has been used in thebuses more and more common. The research on the active control of air suspensionsystem is very important for improving the performance of air suspension system.In this paper, the air suspension system was taken as the research object, to achieveits active control is the goal of the study, Based on vehicle dynamics theory, a vehiclesuspension system of seven degrees of freedom model, a quarter semi-active suspensionsystem model and skyhook suspension system model were established. The motionequations of the vertical, roll, pitch of the center of mass of vehicle body and of thevertical of the four wheels were derived. The two kinds of active controllers for the airsuspension system were designed according to the theory of the fuzzy control and thevariable structure control, and the simulation models of the controllers were establishedin Matlab/Simulink. Some dynamic simulation analysis was did on seven degrees offreedom of the vehicle suspension system model which was controlled by fuzzycontroller, and took the skyhook suspension system as the reference model, somedynamic simulation analysis was also did on the quarter semi-active suspension systemwhich was under the sliding mode variable structure controller’s control. Simulationresults show that the designed controller can effectively achieve the active control of airsuspension system, and the active control performance is stable. All performance of thecontrolled suspension system in the time domain and frequency domain analysis aresignificantly improved. And the results also prove that the air suspension system whichis controlled by fuzzy controller or sliding mode controller can effectively improve thevehicle’s ride comfort, handling stability and security.