Shift Performance Optimization Of A Micro-car Based On NSGA-Ⅱ

The China Association of Automobile Manufacturers (CAAM) announced China had overtaken the United States to become the world's top auto maker and market in 2009 boosted by government stimulus measures. The rapid growth of car sales lead the qualitative change in the Chinese auto market, auto manufacturers have to enhance the competitiveness of their products and they must strictly controlled assembly and parts to improve vehicle quality. Transmission control mechanism as an important component of a vehicle transmission assembly, will give user more direct experience, such as the reliability of vehicles and driving comfort. Most of medium-sized passenger and cargo motor vehicle, because of the cost and other factors, widely used rear-engine rear-wheel drive program with manually transmission. However, this control mechanism is laborious, and often shift to the drivers will bring many inconveniences, resulting in traffic accidents.In this paper, do research on kinematics and static simulation analysis of the transmission control mechanism of a micro-car, and select fast non-dominated sorting genetic algorithm (NSGA-II) as the optimization algorithm. Moreover, develop a multi-objective optimization software for optimizing related parameters of transmission control mechanism by using MATLAB.The major contents are as follows:(1) Reviewed the development history and status of home and abroad related technology, introduced the main contents and key technologies of shifting performance optimization and point out the development trends.(2) Did research on automobile transmission, synchronizer and shift control mechanism, and learned how they work. After analyzing the shifting operation based on human engineering, summarized the impact factors of light shift and made sure optimization targets and methods.(3) The non-dominated sorting genetic algorithm-â…¡(NSGA-â…¡) was chosen to be shift performance optimization algorithm. The paper optimized and designed related parameters by using NSGA-â…¡for the multi-objective structure optimization problem, and made sure that optimum results came up to the standard.(4) The kinematics and static module of shift control mechanism were established based on MATLAB. Transmission shift performance bench test was build to gain data and compared with simulated results.