基于CAN总线的换挡过程控制技术

COORDINATION CONTROL TECHNOLOGY BASED ON CAN BUS IN PROCESS OF SHIFTING

根据机械式自动变速器自动换挡时的需要,分析了在动力一传动系统中应用CAN总线对换挡时间、冲击度和离合器滑磨功的影响,阐述了控制系统中总线报文的详细内容和通信过程,编制了通过总线接收和发送报文的通信程序,在此基础上设计开发了基于CAN总线的应用层协议-SAE J1939的控制模块,实现了电控柴油机转速、油门位置等车辆动力系参数的共享,同时该模块可以在换挡过程中实时控制柴油机的输出转矩和转速。试验结果表明:该项协调控制技术将使柴油机输出特性和变速器换挡过程相互匹配,因而不仅可使自动机械变速器的硬件得到简化,而且有效地减少了换挡时间,降低了离合器磨损,从而改善了换挡品质。

According to the need of automated mechanical transmission＇s automatic shifting, how the application of CAN bus in the power-train system to affect shift time, jerk and abrasion of clutch is analyzed, the details and communication process of message applied in the control system is expatiated, the communication software for receiving and sending message by bus is made. On this base, a control module based on an application layer protocol-SAE J1939 of CAN bus is designed. The module realizes the sharing of engine speed and accelerator pedal position between electric diesel and automated mechanical transmission; at the same time, it can control the output torque and engine speed of diesel in the process of shifting. The test result shows that the coordination control technology make the hardware of automated mechanical transmission more simple because of the matching of the diesel＇s output characteristic and the transmission＇s shift process. The shift time is shortened. The abrasion of clutch is decreased. So the shift quality is improved.