基于发动机协调控制的AMT换挡策略研究
2017-07-12黄冈
黄冈
摘要: 为了改善电控机械式自动变速器(AMT)的换挡品质,分析了换挡过程理想状态下发动机转速、转矩变化的特性曲线,制订了基于CAN总线的换挡过程发动机协调控制策略。提出在换挡过程中,发动机减载和加载阶段通过变速箱干预转矩对发动机输出转矩进行短时的协调控制,空载阶段采用转速闭环PID控制的发动机协调控制策略。为验证该策略的有效性,基于MATLAB/Simulink软件平台搭建了仿真模型,以升档为例,对提出的控制策略进行了仿真验证。仿真结果表明,所提出的发动机协调控制策略能够满足实时性要求,减小离合器滑磨,有助于提高AMT的换挡品质。
Abstract: In order to improve the shift quality of the automated mechanical transmission(AMT), the ideal speed and torque curves of engine during gear shifting process was analyzed. And a CAN bus-based engine coordinated control strategy for gear shifting is worked out. In this paper, an engine coordinated control strategy was introduced for gear shifting process while load and unload conditions were discussed respectively. To be specific, engine torque output was temporarily controlled by transmission coordinated torque during engine loading and shedding process and PID loop control of speeds was applied in the no-load time. The validity of the presented strategy is demonstrated by simulation based on MATLAB/Simulink, which focused on upshift progress. The results show that the proposed strategy could meet real-time requirements, reduce clutch slipping and improve the shift quality of AMT.
关键词: AMT;CAN总线;变速箱干预转矩;协调控制;PID
Key words: AMT;CAN bus;transmission coordinated torque;coordinated control;PID
中图分类号:U463.212 文献标识码:A 文章编号:1006-4311(2017)19-0100-04
0 引言
电控机械式自动变速器(AMT)是在传统的有级式手动齿轮式变速器基础上加装自动换挡机构改进而来的,具有操作方便、制造成本低、传动效率高等优点。由于AMT是有级式变速器,因此,在换挡过程中存在传动比的突变,从而引起换挡冲击,降低了驾乘的舒适性和换挡平顺性[1],所以在AMT换挡过程中需要对发动机和离合器进行协调控制。
在此前的研究中,關于换挡过程的发动机协调控制有一定的相关研究。文献[2][3]通过调节节气门开度来调节发动机转速,以改善换挡品质,这种方式是一种慢转矩调节方式,对于有限的换挡时间来说显然达不到期望的控制精度和响应速度;文献[4]对发动机开展了开环断油控制,文献[5]开展了模糊控制,文献[6]开展了自适应算法控制,但是这几种方式只对发动机的转速进行控制,不能对发动机的输出转矩进行干预,容易在换挡过程中产生转矩突变。……
