Real-time And Reliability Research Of CAN Bus Communication In Automotive Electronics Test Platform

Car is from a mechanized tool becoming a way of people to enjoy life. Research in thefield of automotive electronics becomes the most important part of vehicle development.Today’s society automobile electronic and intelligent degree become more and more higher,people have higher demand in economy, safety and handling with cars, to design automotiveelectronics test platform with testing and monitoring functions, become a kind ofdevelopment trend in the process of the automobile electronic, and also become a necessary inthe development of automobile electronic.CAN bus is a kind of serial communication bus with high performance, high reliabilityand low cost, easy development, due to its superior performance has been widely applied invarious fields, but its the real time and reliability of communication there are still someproblems. With CAN bus as data transmission channel, this paper builds a complete vehicleelectronic test platform, real-time monitoring for electronic equipment in the car, on the basisof the test platform, not only can be real-time monitoring of automobile electronic equipment,but also can research to improve the performance of the CAN bus communication on the testplatform.Firstly, we analyze the development status of automotive electronic testing technology,CAN bus and its real-time communication and reliability. Elaborated the importance of CANfield bus technology in automotive electronic development process, on the further study ofCAN bus communication technology, we put forward the problems of real-time and reliabilityin CAN bus communication: in real-time aspect, with the increasing of network load, thelower priority queuing delay cannot be sure of information frame, will continue to exit the bus,waiting, and in severe cases even exit the competition in the bus; Reliability,because theindustrial site of plug is not solid, high temperature, high pressure and high electromagneticenvironment, may cause certain effect to send data, unable to make data accurate and reliablein its delivery.Secondly, we make further research on priority promotion and time division multiplexingmethods in improving the real-time nature of the CAN bus communication, combining twokinds of algorithm we put forward the priority promotion and time division multiplexingfusion methods, which can improve the real-time performance of the CAN buscommunication. Through the establishment of the reliability function, we analyze the differentredundancy modes of the CAN bus communication reliability in mathematical method. Also we design and build the car electronic testing platform based on, and detailed introduction thehardware and software design of the testing platform. And in the light of the actual needs todevelop a set of good man-machine interface, develop a simple actual application layerprotocol based on iCAN protocol.Finally, the simulation results of CAN bus communication of real-time were given beforeCAN protocol algorithm and improved algorithm in the testing platform, by introducing thereliability function, with mathematical method to analyze the different redundancy of CANbus communication reliability, and do the actual test in the testing platform to the theorywhich we put forward. The results demonstrate that the priority promotion and time divisionmultiplexing fusion methods can reduce the waiting time of information frame queue,effectively improve the real-time of the CAN bus communication; In reliability respect, CANcontroller redundancy mode of the highest reliability, CAN transceiver redundant second, noredundant reliability is the worst.