Optimal Design Of New-type Transmission Gear Train Based On Improved Multi-objective Genetic Algorithm

Transmission is one of the important components of the vehicle powertransmission system, and the automatic transmission put automatic gear shifting intopractice, it not only improves the comfort of driving but also reduces fuel consumption.The design of DCT develops on the basis of manual transmission and remains theadvantages of MT, such as, compact conformation, high transmission efficiency, butDCT has more excellent shift quality which makes DCT become the most populartransmission. Gear transmission is an important mechanical transmission forms. Helicalgears have a quite complex structure which directly affects working performance of thetransmission, so it is necessary to optimize structural parameters of helical gears. Thisarticle presents a new kind of dual clutch transmission of selective output, optimizes thedesign of helical gears with the improved multi-objective genetic algorithm NSGA-II,and the transmission is designed independently by Automotive Engineering TechnologyResearch Institute of Hefei University of Technology. The main contents of this researchare introduced as follows:(1)This paper selects five kinds of automatic transmission for comparison abouttheir structural advantages and a detailed description of the present situation ofautomatic transmission is given.(2) The article introduces the structure characteristics and working principles ofthe new kind of dual clutch transmission. The design process of important parts of thistransmission is mainly introduced. Using Pro/E software build the three dimensionalsolid model.(3) The paper introduces the basic concepts of genetic algorithm and improvementof NSGA-II.(4)The multi-objective optimization mathematical model of the helical gear trainof this transmission is provided with the design objectives of the minimum volume, theminimum center distance and the maximum contact ratio of gear strain, the transmissionstructure and the gear ratio have been already determined.(5)According to the mathematical model, the results of the optimization obtainedwith the method of improved NSGA-II.