发动机ECU故障诊断系统研究

发布时间：2018-05-04 13:51

本文选题：OBD + ECU　；参考：《江南大学》2012年硕士论文

【摘要】：随着汽车保有量的增长，汽车安全越来越成为人们关注的焦点。公众对于环保呼声的日益强烈和环保法规的日益严格，汽车行驶安全性的客观形势和汽车维修保养的复杂性使得汽车配备OBD系统已成为必然。目前国外的OBD系统已经比较成熟，占据了国内OBD市场的垄断地位。其故障诊断大量使用专用集成芯片，且已经制定了一整套的标准。而国内的OBD研究尚处于起步阶段，几乎没有一个实用的产品。当我国要发展自主知识产权的汽车技术时，一方面需要探索故障诊断方法和手段，另一方面要受制于国外繁琐的标准。论文针对某企业开发的柴油机电控系统，较全面地研究了OBD系统各环节的问题和方法。基于自主研发一种低成本、高可靠性、实用性和尽可能具有自主知识产权的OBD产品的目标，课题研究的重点在于研究设计自己的经济可靠的诊断信号获取、处理和失效处理策略以及配套诊断仪的设计，难点在于研发成果要符合国外繁琐的标准而又不失自主知识产权。首先论文研究现有诊断标准以明确柴油机故障诊断的一般项目、诊断处理的一般方法和故障诊断服务接口的一般要求，结合论文研究的柴油机系统的特点确定了本故障诊断系统的整体方案。整体方案包括诊断协议的选取；故障诊断信息的确定、处理的一般策略；在此基础上确定采用J1939协议作为各个ECU之间的通讯协议，采用ISO15765作为ECU与外接诊断仪之间的通讯协议，并对协议做了简要介绍；重点设计讨论了本系统对故障信息的处理策略，包括故障路径的确认、故障信息的存储和清除、故障灯的点亮和熄灭等。其次，，论文选取了冷却液温度传感器、轨压传感器和凸轮转角传感器作为典型传感器进行研究，选取了高速喷油电磁阀作为典型执行器进行研究，分别对其设计了具体诊断功能的接口电路和故障处理策略。并利用Matlab simulink建立诊断模型进行仿真和理论研究，并在此基础上自动生成软件程序。再次，通过实际台架试验和单独的电路实验，证明了设计的正确性和可行性。最后作为诊断系统的不可或缺的一部分，设计了配套故障诊断仪。在论文的结尾，对本研究进行了总结，并对进一步工作进行了展望。经试验证明论文提出的诊断方案是正确可行的，为柴油机故障诊断研究提供了一般方法，也为其它更加复杂的OBD系统提供了经验。
[Abstract]:With the increase of car ownership, automobile safety has become the focus of attention. The increasingly intense public voice for environmental protection and the increasingly strict environmental protection regulations, the objective situation of vehicle safety and the complexity of automobile maintenance and maintenance make it inevitable for automobile to be equipped with OBD system. At present, the foreign OBD system has been compared. Mature, occupy the monopoly position of the domestic OBD market. Its fault diagnosis uses a large number of dedicated integrated chips and has set up a complete set of standards. While the domestic OBD research is still in its infancy, there are almost no practical products. When China is to develop the auto vehicle technology of independent intellectual property, it is necessary to explore the fault diagnosis side on the one hand. Law and means, on the other hand, are subject to the tedious standards of foreign countries.
Aiming at the diesel engine electronic control system developed by a certain enterprise, this paper studies the problems and methods of each link of the OBD system in a more comprehensive way. Based on the independent research and development of a OBD product with low cost, high reliability, practicality and independent intellectual property right, the focus of the research is to study and design its own reliable diagnostic signal. The difficulty of acquiring, processing and failure processing strategies and supporting diagnostic devices is that the research and development results must conform to the tedious standards of foreign countries without losing their intellectual property rights.
First of all, the paper studies the existing diagnostic criteria to clarify the general project of diesel engine fault diagnosis, the general method of diagnosis and the general requirements of the fault diagnosis service interface, and the overall scheme of the fault diagnosis system is determined by the characteristics of the diesel engine system studied in this paper. The overall scheme includes the selection of the diagnosis protocol and the fault diagnosis. On the basis of this, the J1939 protocol is used as the communication protocol between each ECU, and ISO15765 is used as the communication protocol between the ECU and the external diagnosis instrument, and the protocol is briefly introduced. The key design discusses the processing strategy of this system for the obstacle information, including the confirmation of the fault path. The storage and elimination of fault information, the lighting and extinguishing of the fault lights. Secondly, the paper selects the cooling liquid temperature sensor, the rail pressure sensor and the cam rotation angle sensor as the typical sensor, and selects the high-speed fuel injection solenoid valve as a typical actuator and designs the interface electricity of the specific diagnostic function respectively. Road and fault processing strategy. And using Matlab Simulink to establish a diagnostic model for simulation and theoretical research, and on this basis, the software program is generated automatically. Again, the correctness and feasibility of the design are proved by actual bench test and separate circuit experiment. Finally, as an indispensable part of the diagnosis system, the design is designed. Set up the fault diagnosis instrument. At the end of the paper, the research is summarized and the further work is prospected.
The test proved that the diagnosis proposed in this paper is correct and feasible. It provides a general method for the study of diesel engine fault diagnosis, and also provides experience for other more complex OBD systems.

【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH165.3

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