基于STM32的数据采集系统英文文献Word文件下载.docx
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Keywords:
STM32;
dataacquisition;
embeddedsystem;
uC/OS-II;
1.1.Introduction
Thereal-timeacquisitionofvibrationinrotatingmachinerycaneffectivelypredict,assessanddiagnoseequipmentoperationstate,theindustrygetsvibrationdataacquisitionRapidlyandanalysisinreal-timecanmonitortherotatingmachinerystateandguaranteethesaferunningoftheequipment.Inordertopreventfailure,reducemaintenancetime,improvetheeconomicefficiency,Thepurposeoffaultdiagnosissystemcandetectthesedevicesthroughthevibrationsignalacquisitionofrotatingmachinery,andprocessthedataacquisition,thenitwillmaketimelyjudgmentofrunningstateofequipment.Whilethedataacquisitionmoduleisthecorepartofthefaultdiagnosissystem[1-4].Thepracticalapplicationintheindustrialfield,istheequipmentoperatingparameterswillbeacquiredtomonitorequipmentoperatingstate.Intraditionaldataacquisitionsystems,thedatafromacquisitioncardaregenerallysendintothecomputer,andspecificsoftwarewillbedevelopedforthedataacquisition.ThemaincontributionofthispaperhasdesignedtheSTM32platformwithARMtechnology,thathasbecomeatraditionalmainstreamtechnologyinembeddedsystems,andthecollectingdatatowardthedirectionofhighreal-time,multi-parameter,high-precision,whiledatastoragebecomelargecapacity,moreminiaturizationandportable,andthedevelopmentofmulticommunicationmodeandlong-distancefordatatransmission.Soastomeettheactualacquisitionsystemmultitaskingrequirements,thisarticlehasdesignedbasedonSTM32micro-controlleruC/OS-IIsystemofsignalacquisitionsystem.Therefore,inordertomeettheactualacquisitionsystemmultitaskrequirements,thisnoveltyofthisarticlehasdesignedasignalacquisitionsysteminmicro-controlleruC/OS-IIbasedonSTM32.
2.Architectureofdataacquisitionsystem
Dataacquisitionaskeytechnologyformonitoringequipment,recentlyalotofworkhasbeendoneonit.AnembeddedparalleldataacquisitionsystembasedonFPGAisOptimizeddesignedwhichwillmakeitreasonabletodivideandallocatehigh-speedandlow-speedA/D[5].Instead,ithasuseahigh-speedA/D
converterandStratixIIseriesofFPGAfordatacollectionandprocessing,inwhichthemaincontributionisusedoftheCompactPeripheralComponentInterconnect,thesystemhasthecharactersofmodularization,sturdinessandscalability[6].ButremotecontrolwillbeneededinSpecialConditions,thispaperintroducetheembeddedoperatingsystemplatformbasedonWindowsCEanduC/OS-IItodesignaremoteacquisitionandcontrolsystemwiththeGPRSwirelesstechnology[7-8].Inordertoachievethedatasharingofmulti-user,ithasbuildtheembeddeddynamicwebsitefordataacquisitionmanagementanddisseminationwiththeARM9andLinuxoperationsystem[9].AdatacollectionterminaldevicesisdesignedbasedonARM7microprocessorLPC2290andembeddedreal-timeoperatingsystemuC/OS-IItosolvethereal-timeacquisitionofmultichannelsmallsignalandmulti-channeltransmission[10].Ontheotherhands,twoparallelDSP-basedsystemdedicatedtothedataacquisitiononrotatingmachines,andtheinnersignalconditionerisusedtoadaptthesensoroutputtotheinputrangeoftheacquisition,andthensignalpost-processingbythedesignsoftware,whilethemostfrequentlystructureistouseDASandFPGA-based,andsuchprogramsarealsodependentontheDAScost.
Inordertomeetmarketrequirementsoflowpowerconsumption,lowcost,andmobility,Fig.1inthispaperpresentsthedesignoverallstructurediagramofdataacquisitionsystem.ThroughSPIinterface,thesystemgetsthedatacollectionwiththreeaxisaccelerationsensorintotheSTM32controllerofinnerA/Dconversionmodulewith12-bit,thisprocessisnon-interferingparallelacquisition.Oursystemuses240x400LCDandtouchscreenmodulereal-timetodisplaythecollecteddatainrealtime.
2.1.STM32micro-controller
A32bitRISCSTM32F103VET6,usedastheprocessorinoursystem,comparedwithsimilarproducts,theSTM32F103VET6workat72MHZ,withcharactersofstrongperformanceandlowpowerconsumption,real-timeandlow-cost.Theprocessorincludes:
512KFLASH,64KSRAM,anditwillcommunicatebyusingfiveserialportswhichcontainaCANbus,aUSB2.0SLAVEmodeandaEthernetinterface,whatsmoretwoRS232portsarealsoincluded.ThesysteminourpaperextendtheSST25VF016BserialmemorythroughtheSPIbusinterface,thatwillregardasthetemporarystoragewhencollectlargenumberofdata,furthermore,wehavetheA/Dconverterwith12bitsresolution,andthefastestconversionupto1us,with3.6Vfull-scaleofthesystem.Inadditiontodesignofthesystempowersupplycircuit,theresetcircuit,RTCcircuitandGPIOporttoassurancesystemneedsandnormaloperation.
2.2.Dataacquisition
Themachinestateisnormalornotismainlydependedonthevibrationsignal.Inthispaper,toacquirethevibrationdataofrotatingmachineryrotor,wehaveusedvibrationaccelerationtransducersMMA7455Lwhichcouldcollectthedatafromaxisx,y,andzofthecompanyofFree-scale.Thekindofvibrationaccelerationtransducershasadvantageoflowcostandsmallsize,highsensitivityandlargedynamicrangewithsmallinterference.MMA7455Lismainlyconsistsofgravitysensingunitandsignalconditioningcircuitcomposition,andthissensorwillamplifythetinydatabeforesignalpreprocessing.Indataacquisitionprocessofoursystem,theerrorofsamplingstageismainlycausedbyquantified,andtheerrorisdependedonthebitsoftheA/Dconverter,whenweregardthemaximumvoltageasVmax,theADconverterbitsisn,andthequantizationQ=Vmax/2n,then,thequantizationerrorisobeyeduniformdistributionin[-q/2,q/2][13].
ThedesignedSTM32couldbuiltatmostthree12-bitparallelADCinthispaper,whichtheoreticalindexis72dBandtheactualdynamicrangeisbetween54to60dBwhile2or3bitsisimpactedbynoise,thedynamicrangeofmeasurementcanupto1000timeswith60dB.Forthevastmajorityofthevibrationsignal,themaximumsamplingrateof10kHZcanmeetactualdemand,andthehigherfrequencyofcollectionisgenerallyusedinthe8-12bitsAD,thereforeoneofcontributionofthisworkistochooseabuilt-in12-bitA/Dtomeettheaccuracyofvibrationsignalacquisitionandlowercostinthisexperiment.
3.Softwaredesign
3.1.TransplantationofC/OS
Inordertoensurereal-timeandsafetydatacollectionrequirements,inthissystem,akindofRTOSwhosesourcecodeisopenandsmallisproposed.Italsocanbeeasilytobecutdown,repottedandsolidified,anditsbasicfunctionsincludingtaskmanagementandresourcemanagement,storagemanagementandsystemmanagement.TheRTOSembeddedsystemcouldsupport64tasks,withatmost56usertasks,andfourtasksofthehighestandthelowestprioritieswillberetainedinsystem.TheuC/OS-IIassignsprioritiesofthetasksaccordingtotheirimportance,theoperationsystemexecutivethetaskfromtheprioritysequenceandeachtaskhaveindependentpriority.Theoperatingsystemkernelisstreamlined,andmulti-taskingfunctioniswellcomparedwithothers,itcanbetransplantedtoprocessorsthatfrom8-bitto64-bit.Thetransplantinthesystemaretomodifythethreefilesystemstructure:
OS_CPU_C.HOS_CPU.C,OS_CPU_A.ASM.Maintransplantationprocedureisasfollows:
A.OS_CPU_C.H
Ithasdefinedthedatatypes,thelengthandgrowthdirectionofstackintheprocessor.Becausedifferentmicroprocessorshavedifferentwordlength,sotheuC/OS-IItransplantationincludeaseriesoftypedefinitiontoensureitsportability,andtherevisedcodeasfollows:
typedefunsignedcharBOOLEAN;
typedefunsignedcharINT8U;
typedefsignedcharINT8S;
typedefunsignedshortINT16U;
typedefsignedshortINT16U;
typedefunsignedintINT32U;
typedefsignedintINT32S;
typedeffloatFP32;
typedefdoubleFP64;
typedefunsignedintOS_STK;
typedefunsignedintOS_CPU_SR;
Cortex-M3processordefinestheOS_ENTER_CRITICAL()andOS_EXIT_CRITICAL()asopeningandclosinginterrupt,andtheymustsetto32bitofthestackOS_STKandCPUregisterlength.Inaddition,thathasdefinedthestackpointerOS_STK_GROWTHstackgrowthdirectionfromhighaddresstoloweraddress.
B.OS_CPU.C
TomodifythefunctionOSTaskStkInit()accordingtotheprocessor,thenineremaininguserinterfacefunctionsandhookfunctionscanbenullwithoutspecialrequirements,theywillproducecodeforthesefunctionsonlywhentheOS_CPU_HOOKS_ENissetto1inthefileofOS_CFG.H.ThestackinitializationfunctionOSTaskStkInit()returntothenewtopofthestackpointer.
OS_CPU_A.ASM
Mostofthetransplantworkarecompletedinthesedocuments,andmodifythefollowingfunctions.
OsStartHighRdy()isusedforrunningthemostpriorityreadytask,itwillberesponsibleforstackpointerSPfromthehighestprioritytaskofTCBcontrolblock,andrestoretheCPU,thenthetaskprocesscreatedbytheuserstarttocontroltheprocess.
OSCtxSw()isfortaskswitching,Whenthecurrentta