光电式扭矩测量系统设计

REF_Ref168484390\r\h错误！未找到引用源。REF_Ref168484424\h错误！未找到引用源。参考文献[1]杨乐平,李海涛.LabVIEW程序设计与应用.北京:电子工业出版社，1993.1-8[2]张俊谟.单片机中级教程.北京:北航出版社,2001.52-85[3]王元庆.新型传感器原理及应用.北京:机械工业出版社，1997.31-87[4]柏林,王见.虚拟仪器及其在机械中的应用.北京:科学出版社，1998.61-98[5]戴鹏吃,王胜开.测试工程与LabVIEW应用.北京:北京电子工业出版社，1997.24-53[6]丁振良.误差理论与数据处理.哈尔滨:哈尔滨工业大学出版社出版，2002.18-53[7]张风生,徐松柳,张光辉.光电式转矩测量系统.北京:高等教育出版社,1987.36-52[8]朱丹梧.增量式光电编码器信号处理显示电路.北京:清华大学出版社,2005.11-58[9]欧扬,张纪龙.扭矩测试的发展动态和发展方向.北京:中国计量出版社,1997.15-17[10]孟宗,刘彬.回转机械动态扭矩非接触测量的研究.计量学报2005.10-68[11]白文普,杨俊锋,韩佩富.动态扭矩加载器的校定研究.振动测试与诊断,2007.3-55[12]杨俊锋,韩佩富,白文普.基于LabVIEW的在线动态扭矩测试仪设计.电子测量技术,2007.23-63[13]白文普,杨俊锋,韩佩富.基于虚拟仪器的动态扭矩测试系统的研究.微计算机信息,2007.42-58[14]喻洪麟,刘旭飞,吴永烽.光栅扭矩传感器的信号电路设计.光电工程,2005.2009.34-52[15]熊文卓,孔智勇,张炜.光电轴角编码器光电信号正交性偏差的相量校正方法.光学精密工程,2006.23-69[16]杨俊锋.基于虚拟仪器的动态扭矩实验测试系统的研究[硕士论文].燕山大学,河北,2007.32-54[17]蒋利勇,李伟光.绝对式光电编码器的接口装置应用.北京:北京电子工业出版社,1997.44-71[18]陈锡辉,张银鸿编著.LabVIEW程序设计从入门到精通.北京:清华大学出版社,2010.23-67[19]吴杰.光电信号检测原理.哈尔滨:哈尔滨大学出版社,1990.89-107[20]孙培毅,刘正飞.光电技术.北京:机械工业出版社,1992.67-93[21]何兆湘.光电信号处理.武汉:华中科技大学出版社,2007.74-102附录附录1：程序前面板和程序框图附录2：硬件原理图外文资料翻译ThevirtualinstrumenttechnologyDevelopmentoftheinstrumentsystemhasexperiencedalonghistory.Initsearlystageofdevelopment,instrumentsystemreferstothe"analogmeasurementequipmentpure",suchastheEEGrecordingsystemoroscilloscope.Asaspecialsystemiscompletelyclosed,theyincludepowersupply,sensor,analogtodigitalconverteranddisplay,andtheneedformanualsettings,displaydatatodial,converter,ortakethedataforallkindsofprintingonpaper.Atthattime,ifyouwanttofurthertheuseofdata,requirestheoperatortomanuallycopythedataintoanotebook.Sinceallthingsmustbeconstructedtooperate,sotocarryonthethoroughanalysis,theacquireddataorintegratedcomplex/stepsofthetestautomationisverycomplicated,evenimpossiblejob.Untilthe80's,thecomplexsystem,suchaschemicalprocesscontrolapplications,finallyneednotoccupytomultipleindependentinstrumentconnectedtoacentralcontrolpanel,thecontrolpaneliscomposedofaseriesofphysicaldatadisplayequipment,suchasscale,converter,andapluralityofsetsofswitches,knobsandakeycomponent,andspeciallyusedforinstrumentcontrol."Virtualinstrument"thisconceptoriginatedinthelate70's..Changesinthedevelopmentofthemicroprocessortechnologyisabletoeasilyrealizethefunctionoftheequipmentbychangingthedevicesoftware,sointhemeasurementsystemintegratedanalysisalgorithmhasbecomepossible,sotheconceptwillbevirtualinstrumenttechnologytochangetestandmeasurementforthewholeindustry.Atthattime,whenthetraditionalequipmentsuppliersarestillthemicroprocessorandvendordefinedalgorithmisembeddedintotheclosedsystemtheyprovide,atthesametime,anewtrend--Openmeasurementsystem,allowstheusertodefinetheirownanalysisalgorithmandconfigurationdatadisplaymode--havebeguntoform.Thus,theconceptofvirtualinstrumenttechnologywasborn.Virtualinstrumenttechnologyistheuseofhigh-performancemodularhardware,combinedwiththeapplicationofhighlyefficientandflexiblesoftwaretocompleteavarietyoftest,measurementandautomation.Anefficientandflexiblesoftwarecanhelpyoucreateafullycustomizableuserinterface,modularhardwarecanprovidefullrangeofsystemintegration,softwareandhardwareplatformcanmeetthestandardsynchronizationandtimingapplications.ThisisalsothereasonwhytheNInearly30yearsalwaysleadthetestandmeasurementindustrydevelopmenttrend.Onlywithefficientsoftware,modularI/Ohardwareandsoftwareandhardwareplatformforintegrationofthesethreecomponents,inordertogivefullplaytothevirtualinstrumenttechnologyandhighperformance,scalability,lessdevelopmenttime,andexcellentintegrationofthefourmajoradvantages.Softwareisthemostimportantpartofthevirtualinstrumenttechnology.Usetherighttoolsandbydesignorinvokeaspecificprogrammodule,engineersandscientistscanefficientlycreatetheirownapplications,andfriendlyhuman-computerinteractioninterface.Toprovideindustrystandardgraphicalprogrammingsoftware--LabVIEW,notonlycaneasilycompletetheconnectionwithavarietyofhardwareandsoftware,canprovidepowerfuldataprocessingcapability,setthedataprocessing,conversion,storage,anddisplaystheresulttotheuser.Inaddition,alsoprovidesmoremeasurementtoolinteractiveandhighersystemmanagementsoftwaretools,suchasconnectiondesignandtestinteractivesoftwareSignalExpress,usedintraditionalClanguageLabWindows/CVI,accordingtoVisualStudioMeasurementStudioMicrosoftandsoon,canmeetcustomerdemandforhighperformanceapplications.Inthefaceofincreasinglycomplextestandmeasurementapplications,hasprovidedthesolutionofhardwareandsoftwareofthefullrangeof.WhetheryouareusingPCI,PXI,PCMCIA,USBor1394bus,canprovidethecorrespondingmodularhardwareproducts,producttypesfromdataacquisition,signalprocessing,soundandvibrationmeasurement,vision,motion,instrumentcontrol,distributedI/OtotheCANinterfaceandotherindustrialcommunication,haveeverythingthatoneexpectstofind.Highperformancehardwareproductswithflexibledevelopmentsoftware,measurementsystemcancreateacompletelycustomforthetestanddesignengineers,tomeetthevariousrequirementsuniqueapplication.DesignedforthetestingofPXIhardwareplatformdesign,hasbecomethestandardplatformforthetest,measurementandautomationapplications,hasbroughtaturntheworldupsidedownreformopenframework,flexibilityandPCtechnologyanditscostadvantageformeasurementandautomationindustry.PXIasaplatformformodularinstrumentsofindustrialdataacquisitionandautomationapplicationstailored,builtinhigh-endtimingandtriggerbus,withallkindsofmodularI/Ohardwareandthecorrespondingmeasurementsoftware,testyoucancreateacompletelycustomsolution.Whetheritisthefaceofthedataacquisitionapplicationsimple,ormixedsignalhigh-endsynchronousacquisition,withthehelpofPXIhighperformancehardwareplatform,youcanhandleasituationwithease.ThisisthevirtualinstrumenttechnologytobringyouThereisnothingcomparabletothisadvantage.Fouradvantagesofthevirtualinstrumenttechnology:(1)highperformance.VirtualinstrumenttechnologyisdevelopedbasedonPCtechnologyadvantages,socompletely"inherited"thelatestcommercialtechnologiestoreadilyavailablewithPCtechnologyastheleadingfactor,includingfunctionalexcellenceprocessorandI/Ofile,soyouinthehighspeeddataintothediskatthesametimecanrealtimecomplexanalysis.Inaddition,thevirtualinstrumenttechnologytoshowitsmorepowerfuladvantageofthecontinuousdevelopmentoftheInternetandafastercomputernetwork.(2)scalability.Thesehardwareandsoftwaretoolsthatengineersandscientistsnolongercirclelimitedcurrenttechnology.Duetotheflexibilityofthesoftware,onlyneedtoupdateyourcomputerormeasurementhardware,canwithminimalhardwareinvestmentandlittle,evenwithouttheneedforsoftwareupgradestoimproveyourentiresystem.Intheuseofthelatesttechnologyofthetime,youcanputtheirintegrationintoexistingmeasurementequipment,eventuallywithlesscosttoacceleratethetimetomarket.(3)lessdevelopmenttime.ThedriverandApplicationontwolevels,NIefficientsoftwaretechnologyandthelatestcomputer,instrumentationandcommunicationtogether.Thedes.Thedesignofthissoftwareframeworkisdesignedtofacilitatetheoperationoftheuser,butalsoprovidesaflexibleandpowerfulfunction,sothatyoueasilyconfigure,create,release,maintainandmodifythemeasurementandcontrolofhighperformance,lowcostsolution.(4)theseamlessintegration.Virtualinstrumenttechnologyisessentiallyanintegratedhardwareandsoftwareconcepts.Alongwiththeproductfunctionandtendstobemorecomplex,engineersoftenneedtointegratemultiplemeasuringequipmenttomeetthetestrequirementsofcomplete,whiletheconnectionandintegrationofthesedifferentequipmentalwaysspendalotoftime.VirtualinstrumentsoftwareplatformprovidesastandardinterfaceforallI/Odevices,tohelpuserstoeasilyincorporatemultiplemeasuringdevicesareintegratedintoasinglesystem,reducesthecomplexityofthetask.AlCarterUsaIncistheworldleaderinoneoftheworld'sleadingtelecomsequipmentmakers.AccessislocatedinCaliforniaPetaluma,developmentofLitespanaccessplatformofafiberopticdigitalloopcarrier(DLC).DLCcanbeatelephonecompanycentralroomordinarycopperwiretelephoneservicetransferfarther.ThroughLabVIEW,acomprehensivetestplandevelopmentinarelativelyshortperiodoftime.Atthesametime,thetestofachannelunitloop16ANSIforeachchannelunitrequirementsand4ISDNlinesweretested,thecostofeachtesttimeis12minutes.Becausesomechannelunitneedstotestarangeoftemperatureconditions,sothewholetestneedseveraldays.AnengineerAllenKleinAmericaAlcatelLitespanhardwarequalitydepartment,afunctionisaddedintheprogram,sothatthetestcanallday,evenonweekends.Thisfeaturegreatlyexpandingthetestplatform,improvetestefficiency.Virtualinstrumenttechnologyistheresultoftesttechnologyandthecombinationofcomputertechnology,isthecrystallizationofthelatesttwodisciplines,technology,combinesthetesttheory,theoryandtechnologyequipment,computerinterfacetechnology,high-speedbustechnologyandgraphicssoftwareprogrammingtechnology.Virtualinstrumentiscomposedofcomputerhardwareresourceandthecontrolsystemforthedigitalanalysisandprocessing,processcommunicationandgraphicalinterfacesoftware,ittransformstheinstrumentmanufacturerdefinedinstrumentfunctionbyuserdefinedfunctionofinstrument,thatistosaythetraditionalinstrumenttestwasusedinfactoryproduction,propertiesandfunctionoftheinstrumenthasbeenfactorythedefinitioninthefactory,theusercanonlyownrequirementsandneedstoselectanduseaccordingto;andthevirtualinstrumentisonthebaseofsomehardware,theusercanaccordingtothetest,writesoftwaretodefinetheirowninstrumentfunction.Thesamehardwareconfigurationcandevelopdifferentinstruments,suchasdisplayingthecollectedsignalinthetimedomainwaveformintheinstrumentpanel,theinstrumentasavirtualoscilloscope;iftheFFTtransformofthesignalacquisitionintheprogram,sotheinstrumentisthevirtualspectrumanalyzer.TheauthorusedLabWindows/CVItodevelopvirtualwarptensiontesterisusedtotestthechanges,thewarptensioninthework.Applicationareas:thewarptensionsensor.Loomsintheweavingprocess,thewarpdynamictensionforweaving,smoothlyhasgreatinfluence,thetensionistoolarge,easytocausethebreakage,theweavingefficiencyof;insufficienttensioncausedbytheshedisnotclear,theformationofthreehopdefect,clothandgrainisnotclear.Whenpassesthroughtheshaft,warpbarpressureonbothsidesoftheforcetransmission,throughthedowelbartothepressureelasticbeam,thestrain,thestrainthestrainintotheresistancetochange,andthenthroughtheconversioncircuitresistancechangesintothechangeofvoltage,measurevoltage,accordingtosensorcalibrationcanbeobtainedcorrespondingwarptension.Applicationareas:twovirtualsystemofwarptensiontester.Virtualtestingsystemofwarptensiontesteriscomposedofsensors,dataacquisitioncard,interfacebus,hardwaredriverprogramanddevelopmentoftestsoftware,thedataacquisitioncardwith6024E,testLabWindows/CVIsoftwaredevelopmentplatform,runningundertheWindows98operatingsystem.Applicationofthreeareas:signalacquisition.Duetomeasurethewarptensionandspindlerotation,sowith3sensors.Sensor1isthewarptensionsensor,thewarptensionphysicalsignalintoelectricsignal;sensor2isphotoelectricpulsesensor,usedtomeasuretherotationanglesensor;sensor3isHolzer,willHolzerasatriggersignalvoltagemeasurement.Theoutputsignalofeachsensormustpassthroughasignalconditioningcircuitforsignalprocessing(suchasfiltering,amplification),gettheusefulsignaltobemeasuredfromthemixturesignal,sendthedataacquisitioncard,andsuitableforthevoltagerangeofthedataacquisitioncard,thebusstructureissendintothecomputerforprocessing.ThedataacquisitionsoftwaretocontrolthewholeDAQsystem,includingthecollectionoftheoriginaldata,analysisofdata,signalconditioningandaftermultipleswitchsettingcontrolsamplingrateinsoftware,collectingandamplifyingcircuit,andthenthroughthesampleandholdandtheA/Dconverterunitarequantizedintoadigitalsignal,asignalthatcanbeprocessedbycomputer,thethetestsignaliscalculated,analyzed,displayedbythevirtualinstrumentsoftware,andstoretheresults.Applicationareas:fourthedesignofvirtualwarptensiontester.Theseventextpanelontherightofvirtualwarptensiontesterboxsetuserinputcontent,accordingtotheactualmeasurementneedsaswellastheconnectionchannelacquisitioncardbeforestartingthetest.Whenmeasuringinstrument,opentheswitch,theinstrumentcanwork;presstheacquisitiondata,waitafewseconds,thepanelwilldisplaythewaveformofwarptension.Savedataistheoriginaldata,themeasuredsignalprocesseddataanddataaccessisprovidedtotheuser;readingdataisreadpreviouslymeasureddata,thendrawthecurveintheinstrumentpanel,whichisconducivetothepostanalysis;closetheexitstateoftestinstrument.Paneldataacquisition,shutofftheinstrument,savethedataandcommandbuttonthroughacallbackfunctiontoachievetheirfunctions,thecallbackfunctionofCaijidataacquisitionofthesourcecodeoftheprogramisthekey.Fiveapplication:applicationofvirtualwarptensiontester.TheYC-425typeofair-jetloomwarptensiontesterusingthevirtualtestsystemdesignofthemainshaftoftheloom,eachturn,aperiodicvariationofwarptension,atabout0°,thewarptensionisbeneficialtothemaximum,beating,minimumtensionoccurredat280°.Intheory,amaximumvalueappearedintheopeningoffullopenposition,andgenerallyonlytwopeaksinthecurve,inadditiontobeatingpoints,therearetwopeak,thisshowsthatinthebackwithatensionrelievingmechanism.Theminimumtensionisalsorepeatedtensioncurvewarpnotgoodworkingconditionisnotstableenough,thatloom.Virtualinstrumenttechnologyistheuseofhigh-performancemodularhardware,combinedwiththeapplicationofhighlyefficientandflexiblesoftwaretocompleteavarietyoftest,measurementandautomation.Atpresent,thevirtualinstrumenttechnologyhasbeenwidelyappliedintestingindustry,evenautomation,oildrillingandrefining,productionmachinesandcontrolfield.Thetraditionalinstrumentplaysanimportantroleinthemeasurementfield,buttherearealsomanyproblems,suchaslackofflexibility,accuracyisnothighenough.Andthevirtualinstrumenttosolvetheseproblems,moreflexible,andfurtherenhancetheperformanceandprecision,andevensolvethetraditionalmeasurementinstrumentcannotbeachieved,thescalabilityandlowcostmakemanufacturersmoreattentiononvirtualinstrumentand.Usingthemodularinstrumentsoftwareconfigurationbasedonagoodsolutiontotheproblemofresourceallocationandrepetition,isthefuturedirectionofinstrumentdevelopment.WiththerapiddevelopmentofthetechnologyofvirtualinstrumentPCstructuresemiconductordataconverter,highperformance,andintroducesthesystemdesignsoftware,thepromotiontechnologycapabilityandcostreduction.EspeciallywiththecontinuousimprovementofPCperformance,butalsotherapiddevelopmentofthetechnologyofvirtualinstrument,andrealizesanewapplicationofmore.Highperformance,lowcostA/DandD/Aconverteranddevelopment,butalsopromotedthedevelopmentofvirtualinstrumenttechnology.Thehardwareofvirtualinstrumenttechnologycanusethemassproductionofthechipasafrontendcomponentmeasurement.Thesystemdesignofsoftwarehasbecomeamajordrivingforceforthedevelopmentofvirtualinstrumenttechnology,andusinggraphicaldataflowlanguageLabVIEWisalsowidelyusedin.Theextendedfunctionandvirtualinstrumenttechnology,morepowerful,abletodeveloptestprograminPC,intheembeddedprocessorandFPGA(fieldprogrammablegatearray)onthedesignofhardware.Thedesignfortheuserdefinedfunctiontestsystem,hardwareprovidesanindependentenvironment.Therefore,virtualinstrumenthasmanyadvantagesgraduallyreplacedthetraditionalinstrumentplaysanimportantrole,itsapplicationwillbemoreandmorewidely.Virtualinstrumentistheinstrument,measurementandcontrolthedirectionofresearchanddevelopment,NIcompany'sLabWindows/CVIasthesoftwaredevelopmentplatform,whichismuchlowerthantheobjectorientedsoftwareprogrammingdifficultycommonlyusedsoftware,thedevelopmentofhighefficiency,friendlyinterface,powerfulfunctionandexpansibility,good,thecollecteddatacanbeusedforadvancedanalysislibraryforsignalprocessing,caninordertomakethetestcurveofincomeinaccordancewiththeactualsituation,fitting.Inshort,thevirtualinstrumenthasstrongfunction,itstressedthat"softwareistheinstrument",usingsoftwareinsteadofhardware,easytodevelop,easydebugging,caneffectivelysavemoney.Usingthevirtualinstrumenttechnology,theusercandefineaspecialinstrumentsystem,andthefunctionisflexible,easytoconstruct,sotheapplicationisveryextensive.Especiallyinscientificresearchanddevelopment,testingandmeasurement,measuringfieldsistheraregoodtool.Itispowerful,canrealizeoscilloscope,logicanalyzer,spectrumanalyzer,signalgeneratorandothergeneralinstrumentallfunctions,withaspecialprobeandsoftwarecanalsobeparametersdetectionsystemspecificparameters,suchasautomobileengine,gasolinelabel,furnacetemperature,pulse,bloodECGparametersandotherdata.Inthefieldofindustrialcontrol,themajorityofclosed-loopcontrolsystemrequiresaccuratesampling,timelydataprocessingandfastdatatransmission.Thevirtualinstrumentsystemisinaccordancewiththeabovecharacteristics,thedesignisverysuitableforintegrationofthett.Inmanufacturing,excellentcomputingcapabilityofthevirtualinstrumentandthehugedatathroughputcapacitytoplayagreaterroleinthefieldofindustrialcontrol,temperaturecontrolsystem,onlinemonitoringsystem,powermetersystem,processcontrolsystem.Therapiddevelopmentofinformationtechnologyintoday'ssociety,provideagoodfoundationfortheapplicationofcomputeromnipresentvirtualinstrument.Thevirtualinstrumentissuitableforalloccasionstomeasurementdatastorage,dataprocessing,datatransmissionbycomputerassisted.Further,allmeasurementsystem,aslongastechnicallyfeasible,canbeusedinsteadofthevirtualinstrument.Thepowerfulvirtualinstrumentfunctionandpriceadvantage,soithasstrongvitalityandbroadprospectsinthefieldofmeasurementinstruments.Theneweraofelectronicsystemdevelopmenthascome."Graphicalsystemdesign"thissoftwareplatformhasintegratedseveralcalculationmodels,asmuchaspossibletimeandshortenthedesignprocess.Bypublishingtoofftheshelfhardwareprototypeplatformflexible,suchasNIFPGAbasedonCompactRIOplatform,greatlyreducingthefirstprototypeofthetime,andusedtodesigncustomhardwarerequiredtimeandmoneyarereduced.Inaddition,therealityofI/Oresults,prototypinginahigherqualityofdesign--thusavoidingdesignerrorscostlyinsubsequentproductdevelopmentcycle.Finally,inthesamesoftwareplatformrunsthroughthewholeprocessfromthedesigntotheprototypeofthefinalreleasetarget,canmaximizethereuseofcode,andforthefinalreleaseoflowerconversioncomplexity.Therefore,withthehelpofLabVIEW,theusercanhaveafromthedesign,prototypetocompletegraphicalplatformreleasedtoembeddedsystem.虚拟仪器技术仪器系统的发展经历了一段很长的历史。在其早期发展阶段，仪器系统指的是“纯粹”的模拟测量设备，例如EEG记录系统或示波器。作为一种完全封闭的专用系统，它们包括电源、传感器、模拟至数字转换器和显示器等，并且需要手动进行设置，将数据显示到标度盘、转换器，或者采取将数据打印在纸张上等各种形式。在那个时候，如果要进一步使用数据，需要操作人员手动地将数据复写到笔记本上。由于所有的事情都必须要人工去操作，所以要对实际采集到的数据进行深入分析、或者集成复杂的/自动化的测试步骤是很复杂、甚至是不可能完成的工作。一直到80年代，那些复杂的系统，例如化学处理控制应用等，才终于不需要占用到多台独立台式仪器一起连接到一个中央控制面板，这个控制面板由一系列物理数据显示设备，例如标度盘、转换器等，以及多套开关、旋钮和按键组成，并专用于仪器的控制。“虚拟仪器技术”这个概念缘起于70年代末。在当时微处理器技术的发展已经可以通过改变设备的软件来轻松地实现设备功能的变化，所以要在测量系统中集成分析算法已经成为可能，因此虚拟仪器技术的概念将会去改变整个的测试测量行业。在那个时候，当传统仪器的供应商们还在将微处理器和厂商定义的算法嵌入到他们提供的封闭式专用系统中，同时，一个全新的趋势——即打开测量系统、允许用户自己定义分析算法并且配置数据的显示方式——已经开始形成。就这样，虚拟仪器技术的概念诞生了。虚拟仪器技术就是利用高性能的模块化硬件，结合高效灵活的软件来完成各种测试、测量和自动化的应用。灵活高效的软件能帮助您创建完全自定义的用户界面，模块化的硬件能方便地提供全方位的系统集成，标准的软硬件平台能满足对同步和定时应用的需求。这也正是NI近30年来始终引领测试测量行业发展趋势的原因所在。只有同时拥有高效的软件、模块化I/O硬件和用于集成的软硬件平台这三大组成部分，才能充分发挥虚拟仪器技术性能高、扩展性强、开发时间少，以及出色的集成这四大优势。软件是虚拟仪器技术中最重要的部份。使用正确的软件工具并通过设计或调用特定的程序模块，工程师和科学家们可以高效地创建自己的应用以及友好的人机交互界面。提供的行业标准图形化编程软件——LabVIEW，不仅能轻松方便地完成与各种软硬件的连接，更能提供强大的后续数据处理能力，设置数据处理、转换、存储的方式，并将结果显示给用户。此外，还提供了更多交互式的测量工具和更高层的系统管理软件工具，例如连接设计与测试的交互式软件SignalExpress、用于传统C语言的LabWindows/CVI、针对微软VisualStudio的MeasurementStudio等等，均可满足客户对高性能应用的需求。面对如今日益复杂的测试测量应用，已经提供了全方位的软硬件的解决方案。无论您是使用PCI,PXI,PCMCIA,USB或者是1394总线，都能提供相应的模块化的硬件产品，产品种类从数据采集、信号条理、声音和振动测量、视觉、运动、仪器控制、分布式I/O到CAN接口等工业通讯，应有尽有。高性能的硬件产品结合灵活的开发软件，可以为负责测试和设计工作的工程师们创建完全自定义的测量系统，满足各种独特的应用要求。专为测试任务设计的PXI硬件平台，已经成为当今测试、测量和自动化应用的标准平台，它的开放式构架、灵活性和PC技术的成本优势为测量和自动化行业带来了一场翻天覆地的改革。PXI作为一种专为工业数据采集与自动化应用度身定制的模块化仪器平台，内建有高端的定时和触发总线，再配以各类模块化的I/O硬件和相应的测试测量开发软件，您就可以建立完全自定义的测试测量解决方案。无论是面对简单的数据采集应用，还是高端的混合信号同步采集，借助PXI高性能的硬件平台，您都能应付自如。这就是虚拟仪器技术带给您的无可比拟的优势。虚拟仪器技术的四大优势：（1）性能高。虚拟仪器技术是在PC技术的基础上发展起来的，所以完全“继承”了以现成即用的PC技术为主导的最新商业技术的优点，包括功能超卓的处理器和文件I/O，使您在数据高速导入磁盘的同时就能实时地进行复杂的分析。此外，不断发展的因特网和越来越快的计算机网络使得虚拟仪器技术展现其更强大的优势。（2）扩展性强.这些软硬件工具使得工程师和科学家们不再圈囿于当前的技术中。得益于软件的灵活性，只需更新您的计算机或测量硬件，就能以最少的硬件投资和极少的、甚至无需软件上的升级即可改进您的整个系统。在利用最新科技的时候，您可以把它们集成到现有的测量设备，最终以较少的成本加速产品上市的时间。（3）开发时间少。在驱动和应用两个层面上，NI高效的软件构架能与计算机、仪器仪表和通讯方面的最新技术结合在一起。设计这一软件构架的初衷就是为了方便用户的操作，同时还提供了灵活性和强大的功能，使您轻松地配置、创建、发布、维护和修改高性能、低成本的测量和控制解决方案。（4）无缝集成。虚拟仪器技术从本质上说是一个集成的软硬件概念。随着产品在功能上不断地趋于复杂，工程师们通常需要集成多个测量设备来满足完整的测试需求，而连接和集成这些不同设备总是要耗费大量的时间。虚拟仪器软件平台为所有的I/O设备提供了标准的接口，帮助用户轻松地将多个测量设备集成到单个系统，减少了任务的复杂性。阿尔卡特美国公司是全球领先的世界上电信设备制造商领导者之一。位于加州佩塔卢马的接入部，开发Litespan接入平台一种光纤数字环路载波（DLC）。DLC能够将电话公司中心机房普通铜线上的电话业务传递到更远的地方。通过LabVIEW，在相对短的时间内开发了一个全面测试方案。同时测试对每个信道单元的16个ANSI要求的环路和4条ISDN线路的一个信道单元进行测试时，每项测试所花费的时间为12分钟。由于一些信道单元需要测试某个温度范围内的状况，因而整个测试需要几天的时间。AllenKlein美国阿尔卡特公司Litespan硬件质量部的一位工程师，在程序中增加了一项功能，使得测试可以全天进行，甚至在周末也行。这项功能极大地扩展丰富了测试平台，提高了测试效率。虚拟仪器技术是测试技术和计算机技术相结合的产物，是两门学科最新技术的结晶，融合了测试理论、仪器原理和技术、计算机接口技术、高速总线技术以及图形软件编程技术于一体。虚拟仪器是由计算机硬件资源和用于数字分析与处理、过程通讯以及图形界面的软件组成的测控系统，它把仪器生产厂家定义仪器功能的方式转变为由用户自己定义仪器功能，也就是说传统测试中使用厂家生产的仪器，仪器的性能及功能在出厂时已被厂家定义，用户只能根据自己的要求和需要选择和使用；而虚拟仪器是在一定的硬件基础上，用户可根据测试的需求，编写软件定义自己的仪器功能。同样的硬件配置可开发出不同的仪器，例如在仪器面板上显示采集信号在时域的波形，那么该仪器为虚拟示波器；如果在程序中对采集信号进行FFT变换，那么该仪器就是虚拟频谱分析仪。笔者则用LabWindows/CVI来开发虚拟经纱张力测试仪，用来测试织机在工作时经纱张力的变化情况。应用领域一：经纱张力传感器。织机在织造过程中，经纱动态张力对织造的，顺利进行有着很大的影响，张力过大，易引起断头，影响织造效率；张力不足易造成梭口不清，形成