Research Of CAN Bus Protocol And Its Automated Test System

With the gradual transformation of the automotive industry in the direction of digitalization,vehicles are showing a development trend of "intelligence,connectivity,electrification,and sharing".In this context,the electrical functions of vehicle have increased rapidly,making the information exchanged between the ECUs in the vehicle more complex,which not only promotes the upgrade of the electrical and electronic architecture,but also promotes the development and the application of bus technology in the automotive communication field.Currently,the automotive CAN bus is the most widely used bus technology,since its outstanding advantages such as good real-time performance,high reliability and low cost.Automotive CAN bus plays a supporting role in the electronic and electrical architecture of the vehicle,so that the quality of CAN communication will directly affect the realization of the vehicle’s functions and even driving safety.Therefore,it is of great practical significance to study the automotive CAN bus to ensure its communication quality.Due to the complexity and extensive content of the automotive CAN bus system,there are still many deficiencies in the research on vehicle CAN bus network design,controller CAN communication software and hardware development,and CAN bus protocol testing.In response to the above problems,this subject relies on a network project of an automobile factory in Guangzhou,based on the theory of the V model development process in system engineering,to study the automotive CAN bus technology,in order to ensure the stability and reliability of the CAN bus communication in the vehicle.The main contents of the research are as follows:Firstly,the CAN bus protocol is analyzed.Starting from the basic theory and communication mechanism of the CAN bus,the system design work of the automotive CAN network is studied,and the CAN bus layered structure protocol is analyzed layer by layer to clarify the design requirements of the CAN bus in the V development model.Secondly,the CAN software and hardware design is studied.In terms of hardware,the selection and layout requirements of main components is studied based on the idea of modularization;In terms of software,this paper studies the CAN Driver module and other modules,sorts out the CAN message receiving and sending process based on the AUTOSAR architecture,which clarifies the implementation of CAN bus in the V development model.Then,aiming at the problems of CAN bus wide test range and low test efficiency,with the Vector tool chain as the core,a CAN bus automated test system is established,and the test cases and test scripts of the system are designed and developed,which provides a verification method of CAN bus communication.Finally,use the built CAN bus automated test system to verify the validity of the design results.The CAN bus test was carried out on the gateway unit of a certain vehicle and the test data was analyzed and processed.The results show that the function of the CAN bus automated test system runs correctly and meets the design requirements.The research content has been verified by the actual vehicle project,and the CAN bus communication has good stability,which provides strong technical support for the CAN bus development of the automobile factory and has good engineering application value.