| With the rapid development of modern industry,the number of vehicles in the world is increasing year by year,and the world's energy consumption is increasing.While people are pursuing the power,economy and comfort of vehicle,the emission requirements of cars are more stringent.For cars,power and economy are the two most important indexes to evaluate the overall performance of the vehicle,and the matching of its transmission system and the formulation of the shifting schedule are the key factors affecting the power and economy of the vehicle,so it is of great significance to study the optimization of the matching and shifting schedule of the automotive transmission system.Based on the configuration of a 6 in AMT automatic transmission vehicle as the research object,under the condition of meet the demand of the vehicle driving performance,using non dominated sorting genetic algorithm(NSGA ?)and Non-Linear Programming by Quadratic Lagrangian(NLQPL)of the transmission ratio is optimized,and based on Cruise GSP module in software to develop and optimize shift schedule,The contents as following:Firstly,this paper introduces the functions and modeling steps of Cruise software in detail based on the structure of a certain passenger vehicle transmission system,analyzes the parameter meanings of each module of the vehicle,and completes the setting of corresponding parameters.Then,AVL Cruise software is used to build the vehicle simulation model.the simulation calculation task and vehicle evaluation index are set based on the built vehicle model,and the calculation mode is selected and analyzed and the simulation calculation is completed.Finally,the simulation results are compared with the vehicle test results to verify the accuracy of the vehicle model,which lays a foundation for vehicle transmission matching optimization.Secondly,Analyzed the blocking of the drive system main reduction ratio and velocity ratio affect the performance of the vehicle,aiming at the problem of passenger car fuel consumption is higher,select the transmission block transmission ratio and the reduction ratio as optimization variables,with hundreds of kilometers acceleration time,maximum gradeability,maximum speed as a performance evaluation index,with NEDC(New European Driving Cycle)circulating conditions of fuel consumption for economic evaluation indicators,regard the design requirements and vehicle design as a constraint condition,the vehicle drivetrain parameter optimization mathematical model is established.Isight optimization software and Cruise software were integrated to establish a joint simulation model,and NSGA-? and NLPQL algorithm were used to optimize the transmission parameters.The optimization results show that the combined optimization method of NSGA-? and NLPQL algorithm is reasonable and effective,which makes up for the disadvantage of single algorithm optimization and reduces the fuel consumption by11.81% compared with the original vehicle economy.Finally,GSP(Gear Shift Program)module in Cruise software was used to respectively complete the formulation of dynamic and economy-based shifting rules based on the optimal transmission ratio of the transmission system obtained through optimization.According to the driving cycle conditions of NEDC,the optimized optimal economic shifting rules were obtained and the simulation calculation of different shifting rules was completed.The simulation results show that under NEDC cycle conditions,the fuel consumption of dynamic gear shift rule is 8.53L/100 km,the fuel consumption of economic gear shift rule is 7.89L/100 km,and the fuel consumption of optimal economic gear shift rule after optimization is 7.80L/100 km.The research in this paper shows that it is reasonable and effective to adopt the combination optimization algorithm combining NSGA-? and NLPQL to optimize the transmission parameters,and on the basis of obtaining the optimal transmission ratio,it can further reduce the fuel consumption of the vehicle and improve the fuel economy of the vehicle by using the GSP module in AVL Cruise to optimize the shift schedule. |
PDF Full Text Request