CAN总线时间触发机制的实现

2005979EngineeringScienceSep.2005Vol7No9学术论文CAN吕伟杰1,2,刘鲁源1,王毅新1(1天津大学电气与自动化工程学院,2天津大学电子信息工程学院,天津300072)[]CAN,8052CANSJA1000,,CAN,[];;CAN;[]TP336[]A[]1009-1742(2005)09-0040-04[]2004-04-22;2004-10-08[](023183611)[](1975-),,,1引言,,;[1]CAN,,,CAN,,,[2],CAN,,,,,2时间触发机制的基本概念与实验系统21(),CANTTCAN[3],,(),,,(),,,,1,,22CAN,,,1Fig1Constructionofmatrixcycle,,,,22,,2RAM2CANSJA1000CANPCA82C250AT89S52,,,,LED2CANFig2ConstructionofCANcontrolnetwork3CAN总线时间触发机制的实现31CANCAN,:,,CAN,,,:1)T0TB,T0,T0(1ts),2),CANSJA1000TX1,RS,AT89S52INT1,TCONTR1=1,TMODGATE=1,INT1T13)T1,T1(1ta,tb,tc),T1,RS,T11T1,30,321,,1AB;,1,,CAN,1ab321隔离时间窗口a和b的确定ab,,T0T14,T0419:CAN,,8,T1,3,,,,b2ata=12,btb=9T1,322基本周期最大传输消息个数的确定,,CAN20B,,CANLMFS[4]LMFS=(54+8Sm)/5+67+8SmSmCAN,bit,:tm=LMFSbitTB,k,,!max=[TB-ta-(k+1)tb]/tm4网络控制系统的可调度分析MCAN(),Ti(i[1,M])TM,,T=[T1,T2,,TM],Ti+1!Ti,i[0,M-1];K=[k1,k2,,kM],ki=Ti/T1,ki∀ki+1,kiiTiT1;TGCD(T)=TB,TLCM(T)=TM;∀k,∀k=#Mi=11/ki∀k∀!max,MNCANk,bk+1tsm,#k=[TB-tsm-ktm-ta-(k+1)tb]/tmN∀#k(TM/TB),,DmaxTM∀k+#k+1∀!max,∀k+#k+1!max,,,5实例分析,,11Table1MessagesofvehicleenginecontrolsystemT=5msT=5msT=10ms∃T=10msT=10msT=10msT=10msT=10ms1,,5ms,10ms,3B,250Mb/s,107b,0428ms18M1M8,6M9M14,1SM,642ms,5ms,,42712MHz,ta=12%s,tb=9%s!max=10,∀k=5k=5,,#k=3,∀k+#k+1=9!max,,3:3Fig3Messagesschedulingofvehicleenginecontrolsystem1,,,,10ms6结语,,,CAN,TTCAN[3]CAN,,,,CANCANopen,8052CANSJA1000,,,1,,,CAN参考文献[1]AlmeidaL,PedreirasP,FonsecaJAG.TheFTTCANprotocol:whyandhow[J].IEEETransactionsonIndustrialElectronics,2002,49(6):1189~1201[2]ZuberiKM,ShinKG.Nonpreemptiveschedulingofmessageoncontrollerareanetworkforrealtimecontrolapplications[A].ProcRealTimeTechnologyandApplicationsSymposium[C].1995.240~249[3]LeenG,HeffernanD.TTCAN:anewtimetriggeredcontrollerareanetwork[J].MicroprocessorsandMicrosystems,2002,26(2):77~94[4]HongHeeLee,UiHurnJeong.DesignofdistributedscheduleronCANforrealtimenetworking[A].ProceedingsTheFifthRussianKoreanInternationalSymposium,No3[C].2001.22~25TheRealizationofTimeTriggeredControlAreaNetworkLWeijie1,2,LiuLuyuan1,WangYixin1(1SchoolofElectricalandAutomationEngineering,TianjinUniversity,Tianjin300072,China;2SchoolofElectronicInformationEngineering,TianjinUniversity,Tianjin300072,China)[Abstract]ThetimetriggeredarchitectureforCANisanalyzed.Theimplementationissueoftimetriggeredarchitecturebasedon8052singlechipprocessorandCANcontrollerSJA1000isdesigned.Themaximumnumberoftransmissionmessagesinbasiccycleisgiven.Andtheschedulingcapabilityisanalyzed.Theexperimentisbasedontheautomotiveenginemanagement,theresultprovesthatusingtimetriggeredarchitecturecannotonlymanagethemessagetransmissionbutalsoimprovethebandwidthutilization.[Keywords]timetriggered;timesynchronization;CANbus;distributedcontrolsystems439:CAN