Optimization Research On Ride Comfort Of Commercial Vehicle Cab Suspension System

This paper summarizes the present research situation in vehicle vibration performance, analyzes the development trend of the technology using in this area, and discusses the domestic researching levels of the vehicle vibration performance which counting Cab Isolation System, gets a conclusion that the researches on commercial vehicle which has Cab Isolation System is rare, especially the researches aimed at the choosing of Cab Isolation System's parameters and the parameters' matching between Cab Isolation System and Chassis Suspension System. Based on this conclusion, an idea of using Muti-Body System Dynamic theory and modern optimization technology to analyze and optimize the commercial vehicle's Cab Isolation System is presented.Subsequently, according to the demand of the client and the need of the research, Muti-Body System Dynamic theory is chosen and used to build the whole body vehicle model. And also based on the random vibration theory and the international standards, the whole body vehicle ride comfort evaluation principle is established.On basis of the using situation of the vehicle, the characteristics of target commercial vehicle's Cab Isolation System and Chassis Suspension System are analyzed. According to the analysis results, a whole body parametrical virtual reality vehicle model is built, which could use to analyzing same structure vehicle model with differ parameters and similar structure vehicle model. Aiming at the Cab Isolation System without cab displacement limit system, the flexible limit principle of cab's displacement and the problem which linear spring can get nonlinear characteristic are well researched.For known the characteristics of the whole vehicle vibration system, normal mode analysis is used to study the system mode frequency and mode shape, and forced vibration analysis is used to study the system responds. Because the system responds are needed to getting filter and taking all factors' evaluation, a method gain this purpose in ADAMS is stated. This method is simple and quick, it's no need to write extra program or change any data withother mathematics software, just need to process to ADAMS's postprocessing and finish the filter job.In accordance with Cab Isolation System and full vehicle two kind optimization mathematics model, the Cab Isolation System and full vehicle suspension system in turn got optimization. Results shows that only taken Cab Isolation System to optimize the advantages are limited, and taken full vehicle suspension system taken to optimize can get good advantages.Because of the limitation of ADAMS itself, ADAMS can only optimize linear parameters, and the optimization results are linear too. And more important, the linear optimization result in one actuator is not suitable to the other actuators. For getting an optimization result which suits all kinds of actuators, there's an opinion bring out that linear results should be nonlinearization. It's found that the all factors' evaluation value using nonlinear results is better than using linear results.All the studies in this paper offer a valuable analysis method to full floating cab isolation system, and a fine, available optimization method to the same kind of study.