外文翻译--基于虚拟仪器技术的风机性能自动测试系统.doc -- 5 元

英文原文AutotestingsystemforfanperformancebasedonvirtualinstrumentationtechnologyAbstractInaccordancewiththepresentstatusofmeasurementoffanperformancewithburdensomeinlabors,lowinaccuracyandbackwardintestingmethod,autotestingsystemforfanperformancebasedonVirtualInstrumentsVItechnologywasdeveloped.Thesystemintegratedsensortechnology,computertechnologyandmeasurementtechnology.Asaresult,thesystemcannotonlyautomaticallyacquire,processtestingdataandexpressthefinalresultsinsuitableformsbutalsocontrolandadjustdifferentworkingloads.Thewholesystemisfriendlyininterface,easyinoperationandcompleteinfunctions.Theexperimentresultsshowedthatthestabilityoftheexperimentprocessincreased,thereadingerrorwasavoidedandthemeasurementaccuracyandexperimentefficiencywereimproved.Thesystemhasbeenwidelyappliedtomanyfanproductionfactoriesandresearchinstitutes.Keywordsfanperformancetestingautotestingvirtualinstrumentationdataprocessing1IntroductionTheparametersoffanflux,pressure,powerandeficiencynotonlydecideworkingperformancebutalsoarethebasisofselectingandusingblowerforpeople.Becauseoftheblowertheorybeingnotperfect,performancetestingisthemainmethodofacquiringtheseparameters.Moreover,thetestingisimportantfortestingproductsanddesigningnewproducts.InChina,traditionalfanperformancetestingisalwaysdonemanuallyorbysinglechipwhichhasmanyshortagesincludinglowerprecision,heavylaborintensity,unfriendlyuserinterface,andsoon.Therefore,accordingtothedemandsofmoderntimesexperimenttechnique,anautomatictestandanalysissystemforfanperformancebasedonvirtualinstrumentationtoolLabWindows/CVIwasdesignedinthispaper.Combinedsensortechnology,computertechnologyandtestingtechnique,thevirtualinstrumentationVItechnologymakesthemostuseofintelligenceofcomputertothoroughlybreakdownthemodethatthetraditionalinstrumentsaredefinedbythemanufacturers,howevertheuserscannotchange.WithVI,usersareprovidedaspacetoexerttheircapacityandimaginationadequately.Itistheuser,notthemanufacturer,whocandesigntheirown.instrumentsystemattheirpleasureaccordingtopersonalneed.Inthevirtualinstrumentsystem,thehardwareonlyprovidesasolutiontotheinputandoutputofsignals,howeverthesoftwareisthekeytothewholesystem.Anyusermaymodifythesoftwaretochange,increaseordecreasethefunctionsandscalesoftheinstrumentsystem.Asaresult,thesystemcannotonlyautomaticallyacquire,processtestingdataandexpressthefinalresultsinsuitableformsbutalsocontrolandadjustdifferentworkingloads.Thewholesystemisfriendlyininterface,easyinoperationandcompleteinfunctions.Theexperimentresultshaveshownthatthestabilityoftheexperimentprocesshasincreased,thereadingerrorwasavoidedandthemeasurementaccuracyandexperimentefficiencywereimproved.Thesystemhasbeenwidelyappliedtomanyfanproductionfactoriesandresearchinstitutes.2HardwaredesignofthesystemHardwareofthissystem,whichisthebasisofsignalacquisition,conversion,enhanceandprocessing,consistsoffan,motors,windpipe,sensors,computer,dataacquisitionboard,frequencyconversiongovernor,etc.TheblockdiagramofsystemstructureisshowninFig.1.Amongthosecomponents,computerandpluginDAQboardplayanimportantroleinthesystem.WiththehighperformanceDAQboard,notonlydataacquisition,A/Dconversionbutalsofrequencycontrol,stepmotorcontroletcarerealized.Consideredofthetechnicalindexessuchassamplingfrequency,accuracy,A/DD/Aconversionrate,resolution,theDAQboardPCI6024EfromNationalInstrumentsU.S.A,withwhich200ks/s,12bitperformanceon16singleendedanaloginputscanbegotupto,isselected.The6024Efeaturesdigitaltriggeringcapacity,aswellastwo24bit,20MHzcounter/timesand8digitalI/Olines.Two12bitanalogoutputsarealsofeaturedbythe6024E.Thefanparametersflux,staticpressure,torqueandrotationspeedaremeasuredbycorrespondingsensorsincludingdifferentialpressuretransmitterBC69type,accuracyisFS,staticpressuretransmitterJYBtype,accuracyis1FS,andtorquerotatespeedsensorAKC205type,accuracyis0.3FS.Thesensoroutputsareallstandardcurrentsignalwith420mA.TomeettheDAQboardinputsignaltypeandrange,05Vvoltagesignalsareachievedfrom420mAcurrentsignalsbyaninterfaceboardwhichisusedforsignaltransformation.Throughtheanalogoutputchannelon6024E,05Vvoltagesignalwhichiscorrespondingon050HzofACfrequency,aresentouttocontrolfrequencyconverterFRA5401.5KCHtype,MITSUDISHI,Japan.Then,thefanspeedchangeswithvariablevoltage.Theregulatingunitofworkingstatus,whichisdesignedbytheauthors,istherotatingbafflestructurecomposedofroundbaffle,shaftcoupling,creepergearandstepmotoretc.SeetheFig.2.Thiskindofstructurecannotonlyrealizetheautocontrolbutalsoissmallandflexible.ThreedigitalI/Oportonthe6024Eareusedtosendoutthreephasepulsetocontroltherotationangleofstepmotor.Thestepmotordrivestheroundbafflethroughthecreepergeartorevolveinsidethewindpipe,resultinginthechangeofaperturegapbetweentheroundbaffleandwindpipe,therebyalteringthefluxofairflowinsidethewindpipe,namelythealterationofworkingstatusisrealized.Thecreepergearcanpreventthepositionofroundbafflechangingwhentheairflowistoostrong.Toinsurethemeasurementaccuracy,severalantiinterferencemeansareadoptedsuchasdifferentialinputsofsignalstoeliminatethecommonmodeinterference,goodearthofsignallineandinstruments,digitalfilteringtechnologyinsoftware.3Softwaredesignofthesystem3.1DataprocessingDataprocessinginthissystemincludesthreeaspectsprocessingacquiredsignalstoweedoutvariousdisturbingsignalsusinghydrodynamicsformulastocalculateperformanceparametersoffansfittingperformanceparametersbasedonleastsquaremethodtodrawperformancecurvesoffans.3.1.1CalculationofperformanceparametersRefertothenationalstandardGB123685,Aerodynamicsperformancetestprocedureofventilator,theventilatorperformancetestingofthedischargeoutletisachieved.ThefanperformanceparametersarecalculatedasfollowsowhereistheapertureofrestrictionorificeistheflowcoefficientεisthegasexpansioncoefficientρisthegasdensityoffanoutletFitthetorquebetweenmotorandfannistherotationspeedofmotorpstisthestaticpressurePdisthekineticpressureAistheareaofwindpipevisthespeedoftheairflowηistheavailableoutput.3.1.2PerformancecurvefittingTherearemanycurvefittingmethodssuchasexponentialfitting,orthogonalpolynomialfitting.Theleastsquaremethodisadoptedtofitperformanceparametersbecausethecharacteristiccurveoffanismostlyparabola.Whatiscalledleastsquaremethodisstatisticallyprocessingtheobservedvaluesfromexperimentstomakedesiredvalueofobservationequaltoitstheoreticalvalueandrectifytheobservedvalue.UsingthefunctionPolynomialthatisintheadvancedanalysislibraryofLabWindows/CVI,theperformancecurvefittingwascompleted.TheformatoffunctionPolynomialisasfollowsPolynomialdoublex,doubley,intn,intorder,doublez,doublecoef,doublemseThepurposeofthisfunctionistofindthecoefficientsthatbestrepresentthepolynomialfitofthedatapointsx,yusingtheleastsquaresmethod.PolyFitobtainstheitselementoftheoutputarrayandmeansquarederrormseusingthefollowingformulaWiththisfunctionthefluxwholepressurecurve,fluxstaticpressurecurve,andfluxefficiencycurvecanbeachieved.3.2StructureofthesoftwareThesoftwareisdevelopedbyLabWindows/CVIwhichisanintegratedANSICenvironmentforengineersandscientistscreatingvirtualinstrumentationapplications.WithintegratedI/Olibraries,analysisroutines,anduserinterfacetools,LabWindows/CVIdeliverseverythingyouneedforbuildingadvancedtestandmeasurementsystems.Basedonmodulardesignmethodofprogram,8modulesaredesignedinthissystem1Basicparameterssettingusercankeyinthefantypeandenvironmentalparametersincludingatmospherictemperature,humidityandpressureinthismodule.2Dataacquisitionandcontrolparameterssettinginthismodule,thesamplingchannel,controlchannel,samplingrate,signalinput/outputlimitetc3Maincontrolstationthismoduleisthemaininterfaceforoperators.Thevisualizedcontrols,suchaspowerswitch,testingstartswitch,operatingmodeselectingslide,fanspeedselectingslide,andrealtimenumericwaveformdisplayofsignals,aredeliveredinthefrontpanelforuseroperatingthissystemconveniently.4Dataprocessinginthismodule,notonlyoriginaldatabutalsocalculateddataincludingflux,efficiency,powerandtotalpressurecanbeshowninnumericandwaveformform.Moreover,basedonleastsquaremethodthefanperformancecurvecanbefittedwithfreeselectedfitmodule.5Testreportaftertest,operatorscanachievethetestreportincludinggridorgraphtypeoftestdadainthismodule.Also,datasaving,printing,exporting,importingetcareallrealized.6Historyqueryaccordingtothetestnumberandfantype,userscanfindhistoryrecordstheyneedwithnumericorgraphtypedocumentsinthismodule.Thus,aneededtestreportincludingfanperformancecurvecanbedisplayedandprinted.7Experimentalsimulationavisualflashfilmisdesignedforoperatortoknowtheoperatingprocedurewell.8Systemhelpusingthehypertexttechnology,thesystemhelponlineisbuiltwhichconsistsofthreeparts,namely,fanperformancetestsystemoverview,backgroundknowledgeandoperatinginstruction.