The Research On Performance Of Air Suspension Based On Nonlinear Vibration Model

The road friendliness is defined as the damage brought by vehicles to road. With the advance of the society, the rapid development of road transportation, car ownership increased quickly.Road damage gets worse because of it, highway maintenance cost is higher than before, so the improvements of road friendliness for a car becomes more and more important. Road friendliness of vehicles is mainly decided by suspension structure. Suspension is one of the main components of the car, air suspension is a new type of suspension, it uses air spring as the elastic element, the suspension stiffness has typical nonlinear characteristics. The suspension can adapt to the complex road conditions change, ride comforts handling stability and other performances are better than that of traditional suspension. Studying the road friendliness of air suspension has very vital significance.This paper expounds the process of air spring force, analyzes the influence factors of elasticity, and gives the calculation formula, the air spring simulation model of nonlinear vibration is constructed in MATBLAB/Simulink and verifis its correctness through bench test. Then the air suspension simulation model was established based on that, under the C level road input analog driving, uses dynamic load coefficient, road stress factor and road damage factor to evaluate the road friendliness, and compares with the traditional suspension, results show that under the same conditions using air suspension can improve vehicle road friendliness. Put forward the concept of road friendly suspension, and analyzes the influence of suspension parameters on road friendliness, after that several improvement opinions have been given.The nonlinear character of air suspension is very strong and fuzzy control is often applied to nonlinear, time-varying and modeling simple, high control precision system. In order to further improve the road friendliness, builds a new kind of air suspension including fuzzy control. Using fuzzy control Simulation and comparison before and after the improvement of air suspension road friendliness. Results show that the improved air suspension makes less damage to the road, using the fuzzy control system can further improve road friendliness.The nonlinear vibration model of air spring and the fuzzy control method used in this article, for studying and improving road friendliness and other performances of air suspension provide a new train of thought. For the other types of automobile suspension research, also has the certain model function.