在研究了常见的汽车诊断系统及车载诊断装置(OBD)结构和工作原理的基础上,设计了基于STM32F103单片机芯片作为主控电路的随车式汽车发动机故障诊断系统。通过电源电路、外部调试电路、CAN总线通信电路和K线通信电路的设计,实现了通过OBD-Ⅱ诊断接口与汽车ECU进行通信。设计了硬件电路PCB并进行试制,编制了上位机程序将常用诊断协议写入硬件,实现了对常见故障码的读取检测。
On the basis of studying the structure and working principle of common automobile diagnostic system and on-board diagnostic device(OBD),a fault diagnosis system for on-board automobile engine based on STM32F103 microcontroller chip as main control circuit is designed.Through the design of power supply circuit,external debugging circuit,CAN bus communication circuit and K line communication circuit,the communication with vehicle ECU through OBD-Ⅱ diagnostic interface is realized.The hardware circuit PCB is designed and trial-produced,and the upper computer program is compiled to write the common diagnostic protocols into the hardware,which realizes the reading and detection of common fault codes.
