The Research On Stiff Match And Damping Control Of Air Suspension

With the development of the expressway, the vehicles runs faster and faster; there is an increasing desire on the part of passengers for improved ride comfort and handling stability of vehicles. Vehicle suspension system have direct influence on the ride comfort and handling stability, so requirements on suspension systems are getting higher and higher. As the stiffness and damping of the traditional vehicle suspension system are not adjustable, there must be a compromise between the ride comfort and handling stability., According to the theory of random vibration, matched design of the stiffness and damping of suspension can only be conducted which will be good effects under a special condition and at certain speeds. The air spring has the ideal nonlinear character, it is highly tunable and its vibration frequency is low. So Air Suspension Systems are widely applied in vehicles. Air spring has characteristic of variable stiffness so that only adjustable damping can match very wellThis article is based on a MPV as a prototype, the stiffness characteristics of air spring was calculated, An introduction to fundamental characteristics of the suspension system was given. The motion rate between spring rate and wheel rate was calculated. An optimization method was used to obtain the air spring parameters. then he dynamic virtual models of the prototype vehicle and the air suspension vehicle were set up using the ADAMS software. According to the national standard and the test evaluation method on the vehicle handling stability, the steady circular test step input and ride comfort test were performed. The air suspension vehicle performs well and can satisfy the standards. At last a1/4vehicle suspension mathematical dynamic model was established for the sem-active suspension with the variable stiffness and adjustable damping. Designing the fuzzy control law the ride comfort of the MPV has been greatly improved.