Research On Development And Testing Technology Of Automobile Diagnostic System Based On DoIP Protocol

The rapid development of automotive electronics technology has promoted the widespread use of automotive network communication technologies.At the same time,the new round of scientific and technological revolution represented by big data,telematics,autonomous driving and other technologies is on the rise,making the requirements of bandwidth and compatibility of automotive network higher and higher.Automotive network technology dominated by CAN bus has been unable to meet the needs.Traditional Ethernet technology has been rejected by automotive industry due to its electromagnetic compatibility,electromagnetic interference and non-real-time performance.With the continuous attention paid by domestic and foreign automobile manufacturers and semiconductor companies to vehicle-mounted Ethernet,Ethernet standards and chips suitable for automobile environment are formulated and introduced.The architecture system with automobile Ethernet as the backbone network will become the development trend of the next generation of automobile network.At present,consumers are increasingly demanding safety and reliability of automobiles,making the functions of automotive electronic control units increasingly powerful,and the electronic and electrical architectures becoming more and more complex.The traditional on-board diagnostic technology is not enough.The development of automobile Ethernet technology has brought hope to this dilemma.Its high bandwidth and good adaptability are perfectly suited to the needs of current automobile diagnostic systems.Therefore,it has important practical significance for the development of automotive Ethernet diagnostic system and testing technology.Firstly,based on the technical specifications of the ISO 13400 protocol,the architecture of automotive Ethernet diagnostic system and the physical layer connection interface are analyzed.The frame format and parameter definition of the DoIP message are mainly studied.The architecture scheme of automotive Ethernet diagnostic system is proposed,and the connection mode,connection procedure and session flow of the diagnostic communication between the external test equipment and the vehicle are described in detail.Then,based on the UDS service,the bootloader process of the vehicle’s electronic control unit is studied in detail,including the design of the bootloader startup sequence,the establishment of the test device and the vehicle connection,and the bootloader process is emphasized.Secondly,according to the requirements of diagnostic test and the implementation of the Bootloader function,the diagnostic test cases are proposed.Through the analysis of the traditional diagnostic test tools,a special diagnostic test PC software is designed.Finally,through the established offline diagnostic test platform for the actual test of a research vehicle,on the basis of verifying the function of the test software of the host computer,the test cases are executed according to the test specifications,and the relevant test record files and test reports are automatically generated.The analysis of the test results shows that the diagnostic test PC software function is well implemented,can meet the test requirements,and the test record file can be automatically generated and accurate.