An Optimization Design For A New Automatic Transmission Gear Train Base On The Improved NSGA-Ⅱ

The Dual Clutch Transmission is relatively a perfect transmission with goodproduction continuity, smooth shift, fuel economy and dynamic performance, which hasbeen improved on the basis of the original manual transmission. The new gearboxwhich was totally independent research has been get the resource from the selectiveinput dual clutch automatic transmission, the new gearbox create the brakes instead ofdual clutch to control the output of the gearbox, at the same time, the maturely planetarygear system technology has been also put into the new gearbox which can help toreduce the axial size. As the NSGA-II has been a perfect world’s multi-objectiveevolutionary algorithm, with elitist strategy, constraint handling, and no shareparameters and so on, we can get excellent performance, including good convergenceand the diversity algorithm. The improved NSGA-II has been created on the basis ofBanker law and pre-ordering method. We combined the Banker law which can quicklyreduce the members of the set elements with the pre-ordering method create element setwhich the element in it would not dominated by the elements behind it. This articlemainly focused on the new gearbox, the improved NSGA-II has been used to optimizethe planetary gear system.At first, introduce the kinds of automatic transmission including its characteristics,development status, working principles and give the comparison of their advantages anddisadvantages.Secondly, give the summary comparisons of the selective input DCT and our newcreation, introducing the working principle and its structure characteristics of our newideas. At the same time, the planetary gear system also has been introduced including itsdesign principles and considerations.Then, this article, the genetic algorithm, NSGA-Ⅱ, Pareto solution and the Bankerlaw also been introduced. We create the improved NSGA-II including its working stepsand the selecting method of the optimal solutions.At last, Optimize the design of planetary gear train through the improvedNSGA-II, put forward the objective function and its constraints, and get the optimalsolution through Matlab tools and other computing methods.