基于循环工况的重型车辆换挡序列优化

Shift sequence optimization of heavy-duty vehicles based on driving cycle

针对自动变速车辆换挡策略优化问题,以燃油经济性和车辆行驶性能综合最优为目标,利用动态规划(DP)方法,计算并分析了配备自动机械变速器(AMT)的重型车辆在C-WTVC循环工况下换挡序列的最优决策。建立了循环工况下车辆换挡优化问题的动态规划模型;以功率储备作为评价车辆行驶性能的参数指标,建立了包含经济性、行驶性能的多参数指标函数。考虑了AMT换挡期间存在动力中断的特点,对DP方法进行改进,获得了一系列的挡位序列。研究结果显示,与原有两参数换挡规律对比,DP方法得到的挡位序列使车辆总油耗降低了6.4%,行驶性能指标提高了3.5%。研究表明使用DP方法和多参数指标函数可以得到车辆在循环工况下综合性能最优的换挡序列,对AMT重型车辆的自动控制具有指导意义。

Shifting strategy is one of the key technology that determine the performance of automatic shifting vehicles. For the purposes of better fuel economy and better driving performance,a dynamic programming（ DP） method is applied to solve the optimal gear shift sequence for a heavy-duty vehicle equipped with automated manual transmission（ AMT） in standard driving cycle C-WTVC.DP model for shifting sequence optimization problem is built. The multi-parameter indicator function of economic efficiency and drivability is established by using power reserve as the measurement. The computation process of DP is improved according to the characteristic of power interruption during gearshift operation of AMT to calculate a series of shift sequences. The performance comparison between DP strategy and original shift schedule of the vehicle shows that the fuel consumption is reduced by 6. 4% and the drivability indicator is increased by 3. 5%. Research results shows thatthe shift sequence which has optimal multiple performance in driving cycle can be obtained by DP method and multi-parameter indicator function.