车辆最佳动力性泛函表达及数值解法

为研究能够使车辆具有最优动力性能的动力传动系统参数匹配方法,采用泛函分析对传动系速比进行优化,以变速箱速比作为泛函宗量,建立泛函形式的具有通用性的加速时间表达式.根据变分法原理,采用欧拉有限差分法对泛函宗量进行数值求解,得到最优加速性能目标速比.建立无级变速传动系统动态仿真模型,对不同速比控制策略下的加速性能进行对比分析.仿真对比结果表明,车辆按照泛函分析优化后的速比控制策略在全油门下由6 km/h加速到60 km/h的加速时间减少8.79%,在理论上验证了泛函分析应用于速比优化控制问题的有效性. 

Objective Functional and Numerical Solution Method of Vehicle Optimal Dynamic Performance

In order to achieve best dynamic performance of vehicle,a parameter matching method was proposed for vehicle power train. Firstly, the speed ratio of gear box was optimized based on functional analysis theory. Then taking the speed ratios as functional argument, a general functional form of acceleration time was established. The numerical and optimal solutions of speed ratios were obtained based on Euler finite differential method in calculus of variations. Finally, to analyze acceleration performance in different control strategies, a dynamic model of continuously variable transmission was established. Simulation results show that, the acceleration time of 6~60 km/h can decrease by 8.79% in 100% throttle opening based on the functional control strategy, verifying the feasibility of the functional analysis method for optimal ratio control problems in theory.