基于NSGA-Ⅱ算法的两挡AMT换挡规律多目标优化

Multi-objective Optimization of Shift Law for Two-Gear AMTBased on NSGA-ⅡAlgorithm

两挡变速器通过合理的挡位切换改善纯电动汽车的性能。以纯电动汽车两挡电控机械式自动变速器(AMT)为研究对象,兼顾整车的动力性和经济性,提出一种综合换挡规律。建立两挡变速系统的动力性和经济性换挡规律数学模型,以百公里加速时间和单位里程能耗作为优化目标,通过NSGA-Ⅱ算法优化求解得到换挡规律的Pareto最优解,将电机效率作为最优解的选取条件,得到综合性能最优的换挡规律。在MATLAB/Simulink中搭建换挡规律仿真评价模型,对比评价最佳动力性、最佳经济性和综合性能最优换挡规律。结果表明:所提出的对换挡规律多目标优化的方法是有效的,综合性能最优换挡规律能够同时兼顾动力性和经济性。

Two-gear transmission improves pure electric vehicle performance through reasonable gear switching. Taking the two-gear automatic mechanical transmission (AMT) of pure electric vehicle as the research object,considering the power and economy of the whole vehicle,a comprehensive shift law was proposed. The mathematical model of the power and economy shift law of two-gear transmission system was established. Taking 0-100 acceleration capability and energy consumption per mileage as optimization objective,the Paerto optimal solution of shift law was obtained by optimization solution of NSGA-Ⅱ algorithm;and the motor efficiency was taken as the selection condition of optimal solution,and the optimal shift law of comprehensive performance was obtained. In MATLAB/Simulink,the simulation and evaluation model of shift law was built to compare and evaluate the three kinds of shift laws,such as the best power performance,the best economy and the best shift law of comprehensive performance. The results show that the proposed multi-objective optimization method for gear shift law is effective,and the comprehensive performance optimal shift law takes both power and economy into account.