SIMULATION ANALYSIS AND OPTIMIZATION OF AIR SUSPENSION SYSTEM OF A LIGHT COMMERCIAL VEHICLE (MT)

To improve the ride comfort of a light commercial vehicle, the dynamic performance of the hybrid air suspension was analyzed and optimizaed by multi-body dynamics. Through the quasi-static compression test, the dynamic model of the air spring under different air pressures was established, and then the dynamic performance of the vehicle under random and pulse input were studied through the multi-body dynamics simulation. A combined model for ride comfort simulation was established ob basis of Isight, Matlab and Adams/Car. Through performing the sensitivity analysis, the parameters that have a great impact on the ride comfort performance were determined. Finally, the ride comfort of the whole vehicle under random and impulse input is optimized through the Co-simulation platform and NSGA-Ⅱ optimization algorithm. The simulation results of ride comfort after optimization show that: under random input, the root mean square value of weighted acceleration at the driver is reduced by 13.6%, and that at the passenger is reduced by 25.6%; under pulse input, the maximum vertical acceleration at the driver is reduced by 15.9%, and that at the passenger is reduced by 29.4%, and the ride comfort of the whole vehicle is significantly improved.