Investigation On Reliability Of CAN And Its Application Of Light Control System

CAN is a serial bus of high performance and price radio,which has already formed international standard and been recognized one of the most future FieldBus.As a result of using many new technology and unique design,comparing with common communication bus,CAN bus has highly reliability and real-time and flexibility.Because of this,the application scope of CAN has no longer being used by automobile industry,which has already extended through to mechinery industry,robot,nc machine,medical apparatus instrument,household appliances, aviation,aerospace and so on.The complex and scurvy applicational entironment put forward higher demand to the reliability of CAN bus.The paper introduce the CAN Bus characteristics CAN Bus technology and CAN Bus prospect,firstly.analysis CAN reliability aspect deficiency from application environment and error detection mechanisms.Clearing CAN Bus reliability significance.Secondly,the article has deeply analysed the CAN specification,including message transfer,error handling,message filtering and so on.Although they are already being carried out by CAN bus controller,deeply understanding of CAN specification is helpful to practical application,such as the choice of communication and the constitution of applicational protocol. Secondly,the article put forward the physical model of CAN bus,which has researched the length of CAN bus and the amount of network node.thirdly,the article has deeply researched the reliability of CAN bus network from the structure of topology and redundancy aspects,and got the relevant conclusion.Secondly,modeling the CAN Bus driver PCA82C250 and CAN Bus communication medium.Puting forward CAN net physical model which include N nodes.On this basis,researching CAN Bus length and net nodes,obtained the relationship between cable resistivity CAN Bus cross section area net nodes and CAN net Bus length.at last,deeply researching the reliability from topology and redundancy.obtained the reliability model from Bus ring and redundancy net topology structure.Comparing the structure,obtained redundancy ring net is the best choice.Describing composition and reliability of the non-redundant driver-redundant control-redundant and system-redundant.On this basis,the Distributed Control System of light has been designed based on the two-grade CAN bus network,introducing system fuction composition and principle,designing the hardware and software of CAN Bus net nodes,making system applicational protocol,choosing the communication way,researching the main equipment redundance and fault judgement.Completing the hardware and software design and debug,getting good practical effects,according with the theory analyse result.