Multi-objective Optimization On Shift Quality Of AMT Vehicle

Automatic mechanical transmission not only with advantages of automatic transmission high comfort, long service life but also retain the advantages of manual transmission high transmission efficiency, low cost, simple structure as well as easy to manufacture, which more to the pursuit of development trend of functional and low price products, it has a promising prospect in alcohol fermentation. For the development of automotive transmission automation technology has a vital theoretical and practical significance of studying AMT technology.The AMT shift quality is studied in this paper, which based on an actual model matching with AMT combining with the actual engineering project. The main research content is as follows:1) Starting from the structure of AMT, expounded the working principle of AMT system; then analyzed the theory of shift quality and evaluation index; it analyzed the dynamics for shift process of AMT in detail which divided into the clutch separate stage, pick out gear stage, selecting gear stage, put into gear stage and clutch engaging stage, and the dynamic model of AMT shift process was established.2) Engine operating characteristics was analyzed based on the diesel engine performance test, then used the simulation software Simulation X established the corresponding engine model, clutch model and transmission model; The two parameters combination shift schedule was made with the speed and the throttle opening; The vehicle drive-train system simulation model was established on the basis of the sub-model.3) With the degree of shift impact and sliding friction work as a goal of optimization, used a genetic algorithm for multi-objective optimization of shift quality with the rate of change of clutch pressure and shift time as variables.4) By the AMT test bench, the AMT bench performance testing have been carried out by using traditional shift gear shift control strategy and optimization control strategy respectively with first gear up to second gear and second gear down to first gear respectively under 30% of the opening of the throttle,and the experimental results were analyzed.