Design And Implementation Of A Network Performance Analysis System For Vechicle CAN Bus

CAN bus is one of the most widely used field bus on an international level, and ithas been widely applied to communication of the power system and body systemnetwork and control of the vehicle. As the car CAN bus system's complexity, the workin different development stages is different from each other duing in developling, butcontacts with each other, which put forward quite high demand for the developmenttools. At present, those tools are owned by foreign manufacturers and expensive,however the tools at home with single function are more for the later development stage.Therefore, it is necessary to develop a full-featured development tools. It can assist thedevelopers in designing network to improve development efficiency and reducedevelopment costs.This paper focused on the problem that it is difficult to verify and optimizenetwork design early in the design due to the lack of feasible methods and tools at home.This paper used RMA methods and simulation techniques in real-time analysis of CANnetworks, and as a guide, designed and developed a network performance analysis toolfor vehicle CAN bus. This tool with the function of scheduling analysis, simulation andon-line monitoring can show the network performance indicators and evaluate networkin each stage of system development. It solved the problem that it is difficult to evaluatethe network performance in the initial stage of network design, and provided a viablesolution for the CAN network design and optimization.The main contents of this paper:1. After having a further study on the CAN bus agreement standard, this papersummarized the function of CAN layers and communication mechanism and so on.The RMA method was used in the scheduling analysis of CAN network. The busloadrate and message delay time and other performance indicators can be obtained by themethod.2. Based on Object Oriented Programming (OOP) idea, the paper presented thedesign solutions of the whole system. It established the system of use case model withUnified Modeling Language (UML) and described the detailed function modulepartition and interface design of the system.3. Three major functions design and realization processes of the system wereexpounded. This paper designed the methods of the most bad response time, the bus load rate and the system redundancy algorithm. It established CAN state machine modeland described the design and implementation process of scheduling analysis, simulationand on-line monitoring functions by drawing the activity diagrams, timing sequencediagrams and class diagrams with UML.4. The application and verification of the system. Taking the laboratoryindependent designed vehicle engine news model as an object, this paper made ascheduling analysis for it. It designed test cases to test the accuracy of the simulationfunction. Finally setting up test platform to make monitoring function test on theconditions of the CANoe the simulation network and real vehicle network.Through the contrast of test by the CANoe, the results showed that the the NetworkPerformance Analysis System for vehicle CAN network is accurate and reliable. It canbe used in the CAN bus system development.