基于坡度与整车质量辨识的车辆自动变速坡道换挡修正控制研究

Research of Slope Shift Strategy for Vehicle Automatic Transmission based on Slope and Vehicle Mass Identification

采用适应性和跟随性强的变遗忘因子最小二乘法进行坡度与整车质量辨识,在此基础上进行车辆自动变速坡道换挡分层修正控制,将车辆自动变速过程分为上层决策层与下层换挡执行层,上层决策层采集车辆参数进行坡度与整车质量辨识、坡道换挡修正控制决策;下层换挡执行层接收上层辨识决策层的修正控制指令,完成换挡修正执行。仿真结果与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坡度与整车质量,坡道换挡分层修正控制策略可在上坡时适时降挡,有效避免频繁换挡,减少换挡部件的磨损;下坡时适时降挡,充分利用发动机制动力矩特性,减小制动系统的磨损。

The slope and vehicle mass are identified in real time by using the variable forgetting factor least square method which have strong adaptability and good following performance. On this basis,the slope shift hierarchical modification control of vehicle automatic transmission is carried out,the gearshift process of vehicle automatic transmission is divided into the upper identification decision layer and the lower shift executive layer. Through the upper decision-making layer acquisition vehicle sensor signal parameters,the slope and vehicle mass identification,the slope shift modification control decision are carried out. The lower shift executive layer receive the correction control instruction from upper identification decision layer to complete gear shift correction execution. The results of simulation and hardware-in-the-loop test show that,the slope and vehicle mass can be accurately identified by using variable forgetting factor least square method,the slope shift hierarchical modification control strategy can solve the frequent shift and unexpected shift phenomenon and reducing the wear of gear shifting parts. On other hand vehicle could full use of the engine braking torque characteristics,reduce the wear of braking system when downhill slopes.