Simulation Study Of Optimal Matching For Vehicle Power Train

As Chinese growing economy and rapid development of transportation, energy become increasingly prominent. In fact, regardless of the new fuel, ensuring the premise of vehicle dynamics, fuel efficiency is improved, to improve vehicle fuel economy. It is the fundamental method to solve the problem. Therefore, the purpose is used for this design as a starting point, for the car's engine and transmission, in this paper, a reasonable optimization is used for power transmission parameters. Ensure the vehicle dynamic, essentially to improve economic performance. Whether to the car fuel consumption problem or to the issue of energy efficiency has an important applied significance.From a design point of view, vehicle dynamic performance and fuel economy is the fundamental performance of the car. In fact they are excellent or not will be able to determine the vehicles using the least fuel to complete the set distance in the shortest possible time. And this requirement is the fundamental automobile requirement for people. Based on past design experience, improving vehicle engine and transmission performance is possible to improve the performance of vehicle. But consider the whole car, the premise that the vehicle engine and transmission parameter is determined, improve vehicle power-train to a reasonable degree of match, the car's dynamic performance and fuel economy can be essentially improved. Based on the above theoretical analysis, the design of this thesis as follows:About the optimization model, this detailed study matching of the engine and condition, the matching of power-train and engine. The importance of the traditional parameters of vehicle dynamic reasonable optimization is mathematically proved. Not only that, from the view of the rational optimization point, this paper analyzes the vehicle's power and economy model, the multi-objective optimization model of vehicle is determined. The main drive gear ratio and other gear ratio is used as the design variables. The vehicle power and economy is used as the objective function. Requirements of the transmission ratio of each file and vehicle power requirements are used as constraints.About the choice of the optimization, this paper compares the traditional optimization methods and modern optimization methods. The genetic algorithm is focused on, and improves it based on the practical issues addressed by this paper. Strategy with non-elite dominated Sorting Genetic Algorithm NSGA-â…¡is chosen and a solution method is applied. This article design is meeting. It is key described one of the fast non-dominated sorting and crowding of the calculation and comparison. It is final choice the basic parameters of genetic algorithm which is applied to the subject. About real vehicle experiments and result analysis, based on the numerical analysis the car torque curve and character curve is fitted. Optimization program was designed. Finally, the actual vehicle is used as an example. It proved that NSGA-â…¡genetic algorithm for vehicle power-train optimization problems is feasible. It can be obtained the theoretical study and software design models for the results of the actual application are satisfactory.