汽车防抱死制动系统CAN报文通信信号对称性分析

Symmetry Analysis of CAN Message Communication Signal in Automotive Anti-lock Braking System

以汽车防抱死制动系统CAN报文通信测试为背景,在CAN报文测试过程中,受硬件设备测试精度、CAN收发器外围信号干扰、信号滤波过程、待测件自身特性以及测试方法等因素影响,待测件CAN报文信号对称性往往存在一定偏差,而过大的信号对称性偏差会导致总线通信错误。针对此问题,为尽可能准确地得到待测件通信信号的对称性,分别采用示波器手测方式及网络自动化机柜来测试CAN报文通信信号对称性,并对两种方法得到的信号对称性进行偏差分析。通过信号对称性偏差分析,指出了两种测试方法的利弊,同时给出了示波器手测方式的部分测试建议,为后续其它待测件的测试过程提供一定的参考,以便于整车待测件测试过程的顺利进行。

Taking the CAN message communication test of automobile anti-lock braking system as the background, there is a certain deviation in the symmetry of CAN message in the test process due to the factors such as the test precision of hardware equipment, the interference of peripheral signal of CAN transceiver, the process of signal filtering, the characteristics of the test piece and the test method. Excessive signal symmetry deviation will lead to bus communication errors. Aiming at this problem, in order to obtain the symmetry of the communication signal of the test piece as accurately as possible, the symmetry of CAN message communication signal is tested by oscilloscope manual measurement method and network automation cabinet respectively, and the deviation analysis of the symmetry of signals obtained by the two methods is carried out. Through the analysis of signal symmetry deviation, the pros and cons of the test methods and some test suggestions of oscilloscope manual test method are given, which can provide some reference for the follow-up test process of other parts to be tested, so as to facilitate the smooth running of the whole vehicle test process.