Research On Diagnostic Refresh System Based On Vehicle Ethernet

With the development of automobile intelligence and network,the function and structure of automobile ECU are more and more complex.The number of ECUs in the car is up to more than 100,which puts forward higher requirements for software upgrade of ECU.As a key part of the vehicle diagnosis,the diagnostic refresh system plays an important role in the software upgrading of vehicle ECU.Designing a safe,reliable and efficient diagnostic refresh system can greatly improve the performance of ECU software upgrades.The current diagnostic refresh system based on CAN bus has low efficiency and long updating time due to its insufficient bandwidth.To solve above problems,this paper based on the diagnostic development project of a whole car factory in Guangzhou,and combines with Ethernet technology to design a diagnostic refresh system based on vehicle Ethernet,and focuses on the system of the refresh system tools and ECU Bootloader that to solve the problems of insufficient bandwidth and long update time of the current ECU software upgrade.The main research work of this paper is as follows:Firstly,this paper designs the diagnostic refresh system based on vehicle Ethernet.According to the project and system requirements,the overall architecture of the refresh system tool and the lower computer Bootloader is analyzed and designed,and the interaction between them is studied.By analyzing UDS unified diagnosis service,the types of diagnosis service involved in the diagnostic refresh system are determined,the key contents of vehicle Ethernet diagnosis protocol and HIS standard are analyzed,and the underlying driver module is designed.Then,design and implement Bootloader and refresh system tools.Aiming at the realization of the lower computer Bootloader,this paper takes Infineon TC297 chip as the hardware platform and develops it based on C language.It focuses on the design principle,working mechanism and key data structure of the main modules.At the same time,in order to ensure the safety of the Bootloader,a dual integrity check mechanism is innovated to improve its safety design.The refresh system tool is based on CANoe software development,and uses CAPL language for logic implementation.It focus on the design of its software interface and detailed analysis of its software functions and logic.In order to achieve system functions and meet the needs of the research project,the diagnostic refresh process is designed in detail.The refresh system tool communicates with Bootloader based on Ethernet,and the refresh process conforms to the requirements of unified diagnostic service and Ethernet protocol format.Finally,an experimental environment is built to conduct a joint test of the refresh system tool and the lower computer Bootloader software in the entire vehicle Ethernet diagnostic refresh system.The test results show that ECU can complete the refresh efficiently,which verifies the feasibility and effectiveness of the diagnostic refresh system based on vehicle Ethernet.Combined with the project requirements and production needs,several test cases are designed to test the Bootloader function to ensure its safety and reliability.Under the same environment,the comparative simulation experiment with CAN bus diagnostic refresh is carried out.The results show that the diagnostic refresh efficiency based on vehicle Ethernet is increased by more than 15 times,and it has a very high refresh efficiency,which has important guiding significance and engineering application value for the cost control of enterprise development projects.