The Design Of Fault Diagnosis System Of Automotive Body Network Node

Along with the rapid development of science and technology and people’sdiversified demands for car, automobile electronic technologies are rapidlyprogressing. A large number of automobile electronic systems are used in automobile.Electronics, communications, computers and other disciplinary knowledge areblending in, which greatly deepens the technological content of automobiletechnology. Thus, the fault diagnosis research of automobile electronic is gettingmore and more attention. Automobile electronic systems such as fuel injection system,anti-lock braking system and body network systems can be seen as separate modules.Each system has its own characteristics and working condition, so the specified andtargeted fault diagnoses method complete tasks better. Body network system is animportant part of a car, consists by many network nodes,and is closely related topassengers’ comfort and driving safety. Electronic devices on the network nodes arenumerous and miscellaneous, and network nodes distributed throughout the car body,which has increased the difficulty of diagnosis.This paper introduces the developing situation of automobile fault diagnosis andvehicular networking technology both at home and abroad. Also, it analyzes thecommonly used network topology structure. According to the network topologystructure and the characteristics of car body network nodes, it researches the commonbody network node layout of both centralized one and distributed one. Then wediscuss the technical characteristics of CAN bus and the principle of the on-boarddiagnosis method. While proposing a body network nodes fault diagnosis scheme, itstudies and analyzes the in-depth standard specification of network layer ISO15765-2and application layer ISO14229. Base on ISO15765-2of specification contents of thereference mark would design the communication parameters and timing processing ofthe network layer. While, from the25standard services, the application layer selects10suitable diagnosis service functions for automobile body network nodes.According to the characteristics of body network nodes, it increases or decreases thesub-function for each diagnostic service, refines the specific parameters and faultjudgment algorithm. Finally, the network layer and application layer softwareproposed a scheme, wrote code and complete the diagnose process. At the same time,it optimizes the Bootloader function software solutions of Freescale, and completesthe Bootloader software code. Meanwhile, this paper has developed diagnostic software based on Windows system, and completed the function of client sidediagnosis. Through the diagnostic software and the body network system platformcommunication, it completes the fault diagnosis method quite well.