Design And Robust Research Of Automotive Ethernet Diagnosis System

The CAN bus has become the standard bus for automotive computer control systems.However,the problem of insufficient CAN bus bandwidth has become increasingly prominent with the explosive development of automotive electronics technology.As a supplement to the CAN bus,100 Mbps bandwidth Automotive Ethernet has been used in high-end mass production models at home and abroad.It is particularly necessary to study Automotive Ethernet diagnostic systems with the popularization of Automotive Ethernet applications,.The Automotive Ethernet diagnosis system realizes the diagnosis service through UDS(Unified Diagnostic Service)on IP,and UDS on IP needs to run on the physical layer of the Automotive Ethernet.UDS on IP based on the DoIP protocol,or UDS on DoIP,started the application process with the completion of the standardization of the DoIP(Diagnostic over Internet Protocol)protocol that describes the underlying diagnostic communication of the Automotive Ethernet(ISO 13400).On this basis,designing UDS on DoIP that meets application requirements has important practical significance.Based on the full study of ISO 14229 and ISO 13400 standard,the overall framework of UDS on DoIP is proposed and the specific implementation process is designed.The USB(NCM)interconnection module is designed based on i.MX6 Q according to the implementation process,the design of the transmission module,DoIP frame packing and unpacking,network middle layer,negative response priority and diagnostic service are implemented through the X86 platform.The designed UDS on DoIP is subjected to simulation tests,portability tests,real vehicle data verification and performance tests with using the message accuracy and functional consistency as evaluation indicators relying on the BH-5HA instrument of a Wuhan technology company,the accuracy,portability of the UDS on DoIP and the feasibility of the simulation test program are verified,and three main factors that affect the robustness of UDS on DoIP are analyzed according to the principle of robustness.The results show that the UDS on DoIP designed in this thesis can be transplanted into Linux and QNX operating system,the message accuracy of the actual vehicle data test is 100%,and the function is consistent with the expectations described in the BH-5HA diagnostic parameter table,the response message of the simulation test is the same as the actual vehicle data test without any abnormal,and it has good robustness under extreme loads,external malicious attacks and continuous improper operation.