基于质量与坡度辨识的汽车自动变速器换挡控制研究

A Research on Shift Control of Vehicle Automatic Transmission Based on Vehicle Mass and Road Slope Identification

采用适应性和跟随性强的变遗忘因子最小二乘法进行整车质量和道路坡度辨识,在此基础上提出汽车自动变速器坡道换挡分层修正控制策略,将汽车自动变速器换挡控制分为上层决策层与下层换挡执行层,上层决策层采集汽车参数进行整车质量和道路坡度辨识、换挡修正决策;下层换挡执行层接收上层决策层的修正控制指令,完成修正换挡。仿真和硬件在环实验结果表明:变遗忘因子最小二乘法可准确识别整车质量和道路坡度,换挡修正控制策略可在上坡时有效避免频繁换挡,减小换挡部件的磨损;下坡时充分利用发动机制动,减小制动系统的磨损。

The least squares method with variable forgetting factor,which has strong adaptability and following perl'ormance,is used to identify vehicle mass and road slope.Based on this,a hierarchical correction control strategy for the hill shifting of an automatic transmission vehicle is proposed,in which the shifting control is divided into two layers:upper layer for decision making and lower layer for execution.The upper layer identifies vehicle mass and road slope based on vehicle parameters collected and makes decision of shifting correction;while the lower layer executes the corrected shifting according to the correction control instruction from upper layer.The results of simulation and hardware-in-the-loop test show that using the least squares method with variable forgetting factor can accurately identify vehicle mass and road slope,and the shifting correction control strategy can avoid frequent shifts up the hill and make full use of engine braking down the hill,hence reducing the wear of shifting parts and braking system.