數(shù)控車削中心工件誤差實(shí)時(shí)預(yù)報(bào)外文文獻(xiàn)翻譯、中英文翻譯、外文翻譯

XX設(shè)計(jì)(XX)外文資料翻譯系別：專業(yè)：班級(jí)：姓名：學(xué)號(hào)：外文出處:IntJAdvManufTechnol附件：1.原文；2.譯文20XX年01月IntJAdvManufTechnol(2001)17:649–6532001Springer-VerlagLondonLimitedReal-TimePredictionofWorkpieceErrorsforaCNCTurningCentre,Part1.MeasurementandIdentificationX.LiDepartmentofManufacturingEngineering,CityUniversityofHongKong,HongKongThispaperanalysestheerrorsourcesoftheworkpieceinbarturning,whichmainlyderivefromthegeometricerrorofmachinetools,i.e.thethermallyinducederror,theerrorarisingfrommachine–workpiece–toolsystemdeflectioninducedbythecuttingforces.Asimpleandlow-costcompactmeasuringsystemcombiningafinetouchsensorandQ-setterofmachinetools(FTSFQ)isdeveloped,andappliedtomeasurethework-piecedimensions.Anidentificationmethodforworkpieceerrorsisalsopresented.Theworkpieceerrorswhicharecomposedofthegeometricerror,thermalerror,andcuttingforceerrorcanbeidentifiedaccordingtothemeasurementresultsofeachstep.Themodelofthegeometricerrorofatwo-axisCNCturningcentreisestablishedrapidlybasedonthemeasurementresultsbyusinganFTSFQsetterandcoordinatemeasuringmachine(CMM).ExperimentalresultsshowthatthegeometricerrorcanbecompensatedbymodifiedNCcommandsinbarturning.Keywords:Dimensionmeasure;Erroridentification;Geo-metricerror;Turning1.IntroductionInrecentyears,ultraprecisionmachininghasmaderemarkableprogress.Somespeciallatheshavebeenabletomakeultra-precisionmachining,tolessthanasubmicronandnanomicrontolerancesapossibility.Acommonsecondapproachisthatthegrindingisusedtoachieveahighlevelofdimensionalaccuracyafterturning.However,theconditionofthecuttingtool(diamond)andworkpiece(aluminium)haverestrictedtheapplicationofultraprecisionlathes.Thesecondapproachincreasesthenumberofmachinetoolsandmachiningprocessesused[1],whichresultsinanincreaseinthemanufacturingcost.Atpresent,mostCNClathesareequippedwithapositioningresolutionof1urm.Variousmachiningerrorsinfinishturning,however,degradetheaccuracytoalevelofapproximately10urm,sothatwhenturningcarbonsteel,amachiningerrorpredictablyarisesinexcessof20–30urm.Forimprovingmach-iningaccuracy,themethodofcarefuldesignandmanufacturehasbeenextensivelyusedinsomeCNClathes.However,themanufacturingcostbasedontheabovemethodwillrapidlyincreasewhentheaccuracyrequirementsofthemachinetoolsystemareincreasedbeyondacertainlevel.Forfurtherimprov-ingmachineaccuracycost-effectively,real-timeerrorpredictionandcompensationbasedonsensing,modellingandcontroltechniqueshavebeenwidelystudied[2],soultraprecisionandfinishtuningcanbeperformedononeCNClathe.Thepositioningresolutionofthecuttingtoolsandworkpieceisreducedsothatitcannotmaintainhighaccuracyduringmachiningbecauseofthecutting-force-induceddeflectionofthemachine–workpiece–toolsystem,andthethermallyinducederror,etc.Ingeneral,apositioningdeviceusingapiezo-eletricactuatorisusedtoimprovetheworkingaccuracy,butthemethodintroducessomeproblems,suchas,thefeedbackstrat-egy,andtheaccuracyofsensors,whichaddtothemanufactur-ingcostoftheproducts.However,iftheworkpieceerrorcanbemeasuredbyusingameasuringinstrument,orpredictedbyusingamodelling,theturningprogramproducedbymodifiedNCcommandscanbeexecutedsatisfactorilyonaCNCmachinetool.Thus,aCNCturningcentrecancompensateforthenormalmachiningerror,i.e.themachinetoolcanmachineaproductwithahighlevelofaccuracyusingmodifiedNCcommands,inrealtime.Theworkpieceerrorderivesfromtheerrorintherelativemovementbetweenthecuttingtoolandtheidealworkpiece.Foratwo-axisturningcentre,thisrelativeerrorvariesastheconditionofthecuttingprogresses,e.g.thethermaldeflectionofthemachinetoolistimevariant,whichresultsindifferentthermalerrors.Accordingtothevariouscharactersoftheerrorsourcesoftheworkpiece,theworkpieceerrorscanbeclassifiedasgeometricerror,thermallyinducederror,andcutting-force-inducederror.Themainaffectingfactorsincludethepositionerrorsofthecomponentsofthemachinetoolandtheangularerrorsofthemachinestructure,i.e.thegeometricerror.Thethermallyinducederrorsofthemachinetool(i.e.thethermalerror),andthedeflectionofthemachiningsystem(includingthemachinetools,workpiece,andcuttingtools)arisingfromcuttingforces,arecalledthecutting-forceerror.Thispaperanalysestheworkpieceerrorsourcesinturning.Theerrorsofamachinedworkpiecearemainlycomposedofthegeometricerrorofthemachinetools,thethermallyinducederror,andtheerrorarisingfrommachine–workpiece–toolsys-temdeflectioninducedbythecuttingforces.Asimpleandlow-costmeasuringinstrumentfortheworkpiecedimensions,whichcombinesafinetouchsensorandmachinetoolQ-setter(FTSFQ),isdescribed,andappliedtomeasuretheworkpieceerror.Anewmethodforidentifyingthegeometricerror,thethermalerror,andthecutting-forceerrorisalsopresentedforatwo-axisturningcentre.Finally,themodellingofthegeo-metricerrorofaCNCturningcentreispresented,basedonthemeasurementresultsusingtheFTSFQandCMM.ThegeometricerrorcanbecompensatedbythemodifiedNCcommandmethod.2.ErrorSourcesinTurningThemachinetoolsystemiscomposedofthedriveservo,themachinetoolstructure,theworkpieceandthecuttingprocess.Themajorerrorsourcesderivefromthemachinetool(thermalerrors,geometricerrors,andforcedvibrations),thecontrol(driveservodynamicsandprogrammingerrors)andthecuttingprocess(machinetoolandcuttingtooldeflection,workpiecedeflection,toolwear,andchatter)[3].Errorsderivedfromthemachinetoolincludethermalerrors(machinethermalerrorandworkpiecethermalerrors),geo-metricerrors,andforcedvibrations,whichdominatemachiningaccuracy.Thethermalerrorsandgeometricerrorsarethedominantfactorswithrespecttomachiningaccuracyinfinecutting.However,machinetoolerrorscanbedecoupledfromtheothererrorsourcesandcompensated[4].Theerrorderivedfromforcedvibrationcanbereducedthroughbalanceddynamiccomponentsandvibrationisolation[3].Theerrorsderivedfromthecontroller/drivedynamicsarerelatedtothecuttingforcedisturbancesandtheinertiaofthedriveandthemachinetable.Theseerrorscanbereducedbyaninterpolatorwithadecelerationfunction[5]orbyanadvancedfeeddrivecontroller[6],theseerrors,reducedbyusingtheabovemethods,aresmallwhencomparedwithothererrorsources.Owingtothedemandforhighproductivity,highfeedratesandlargedepthsofcutarerequired,whichresultinlargecuttingforces.Therefore,thecutting-forceinduceddeflectionsofthemachinetool(spindle),toolholder,workpiece,andcuttingtoolmakesignificantcontributionstomachiningaccu-racyduringthecuttingprocess.Inaddition,toolwearandmachinetoolchatterarealsoimportanterrorsourcesinthecuttingprocess.However,theseeffectsareneglectedheresoastofocusonthemainerrorsources.Inshort,theerrorofamachinedworkpiece,i.e.thetotalmachiningerror(iTot),iscomposedmainlyofthegeometricerrorsofthemachinetool(s)(i),thethermallyinducederror(iT),andtheerror(i)arisingfromthedeflectionofthelmdyegHence,iTotiG+iT+iF (1)Inthenextsection,wepresentanovelcompactmeasuringinstrumentandanewanalyticalapproachformeasuringandidentifyingworkpieceerrorsinturning.3.ACompactMeasurementSystemContactsensors,suchastouchtriggerprobes,havebeenusedtomeasureworkpiecedimensionsinmachining.Inmachiningpractice,themeasuringinstrumentisattachedtooneofthemachine’saxestomeasureasurfaceontheworkpiece.ATP7MorMP3associatedwiththePH10MrangeofmotorisedprobeheadsoraPH6MfixedheadhavebeenusedwidelyintheautomatedCNCinspectionenvironmentowingtotheirhighlevelofreliabilityandaccuracyandintegralautojoint.Thoughtheprobeheadsareofadequateaccuracy(unidirectionalrepeatabilityatstylustip(highsensitivity):0.25urm;pre-travelvariation360(highsensitivity):±0.25urm),andversatileinapplication,theyhavecleardrawbacks,includingcomplexityofconstruction,highprice($4988),andtheneedforcarefulmaintenance.Toovercomethesedrawbacksoftouchtriggerprobes,Ostafievetal.[7]presentedanoveltechniqueofcontactprobingfordesigningafinetouchsensor.Thecuttingtoolitselfisusedasacontactprobe.Thesensoriscapableofyieldingmeasurementaccuracycomparabletothatofthebesttouchtriggerprobeinuse.Moreover,theprincipleofoperationandconstructionofthesensorisextremelysimple,thecostofthesensorislow,andthemaintenanceisveryeasy.Inthispaper,thissensorwillbeusedtomeasurethediameterofaworkpieceassociatedwiththeQ-setter.AtouchsensorismountedonaCNCturningcentre.Whenwemanuallybringthetoolnoseintocontactwithit,aninterruptsignalisgeneratedfortheNCunittostopanaxis.Moreover,itcanwriteinanoffsetandaworkpiececoordinateshiftautomatically.Thisfunctionfacilitatesset-upwhenreplac-ingatool,andthisconvenientfunctioniscalledthe“QuickToolSetter”or“Q-setter”.Basedontheaboveprinciple,wecanoperateaswitch,whichiscontrolledbyfinetouchsensor,betweentheQ-setterandNCunit.Whenthetooltiptouchestheworkpiecesurface,thefinetouchsensorcansendacontrolsignaltotheswitch,toturnittothe“off”state.SeeFig.1,thefinetouchsensorreplacestheQ-setterfunction,tostopanaxisandwriteinanoffsetandaworkpiececoordinateshiftautomatically.Therefore,thefinetouchsensorassociatedwithFig.1.FlowdiagramofafinetouchsensorfixedonaCNCcontrolleraQ-setter(FTSFQ)canbeusedtoinspectthediameteroftheworkpiece,themethodisshowninFig.2.Whenthecuttingtooltiptouchestheworkpiecesurface,a“beep”soundisheardandtheswitching“OFF”signalappearsandtheaxisstopsautomatically,asfartheQ-setter.Anew“tooloffset”T-WisobtainedbytheNCunit(displayofCNC).Beforetouchingtheworkpiecesurface,thecuttingtooltiptouchestheQ-setter,andthe“tooloffset”T-Qisobtained.Thus,theon-machineworkpiecediameteron-machineisgivenbythefollowingEq.:Don-machine2H+XT-QXT- (2)whereXT-QisthetooloffsetwhenthecuttingtoolcontactstheQ-setterXT-Wisthe“tooloffset”whenthecuttingtoolcontactstheworkpiecesurfaceHisthedistancefromthecentreoftheQ-settertothecentreofthespindleinthex-axisdirectionandisprovidedbythemachinetoolmanufacturer,fortheSeiki-SeicosLIITurningcentre,itis85.356mm.OstafievandVenuvinod[8]testedthemeasurementaccuracyofthefinetouchsensor,performingon-machineinspectionofturnedparts,andfoundthatthemethodwascapableofachiev-ingameasurementaccuracyoftheorderof0.01urmundershopfloorconditions.However,themeasurementaccuracyofthefinetouchsensortogetherwiththeQ-setterobtainedanaccuracyofabouturmbecausetheresultsofthemeasurementsystemaredisplayedbytheCNCsystem,andthereadingsaccuracyoftheCNCsystemisupto1urm.4.IdentificationofWorkpieceErrorsFromtheaboveanalysisoferrorsourcesoftheworkpiece,thetotalerroriTotofmachinedpartsismainlycomposedofthefollowingerrorsinaturningoperation:.iGthegeometricerrorsofmachinetools..iTthethermallyinducederror.Fig.2.InspectionforthediameterofaworkpiecebyusingthefinetouchsensorwiththeQ-setterofamachinetool..iFthecuttingforceinducederror.Toanalysetheerrorsourcesofamachinedworkpiece,Liu&Venuvinod[9]usedFig.3toillustratetherelationshipamongstdimensionsassociatedwithdifferenterrorcomponentsinturning.InFig.3,desisthedesireddimensionoftheworkpiece;omwisthedimensionobtainedbyon-machinemeasurementusingFTSFQimmediatelyafterthemachiningoperation;omcisthedimensionobtainedbyon-machinemeasurementusingFTSFQafterthemachinehascooleddown;andppisthedimensionobtainedbypost-processprocessmeasurementusingaCMMaftertheworkpiecehasbeenremovedfromthemachine.Whentheworkpiecehasbeenmachined,andremovedfromthemachinetoolsystem,itisthensentforinspectionofthedimensionsusingaCMM.Thisprocedureiscalledpost-processinspection,bywhichweobtainitppvalue.AsthepositioningerroroftheCMMisverymuchsmallerthanthedesiredmeasurementaccuracy,thetotalerrorisiTot(ppDde)/2 (3)ThedimensionDomwisobtainedthroughon-machinemeasurementusingFTSFQimmediatelyaftermachining,i.e.themachineisstillinthesamethermalstateasatthetimeofmachining.Themeasurementismadewiththesamepositioningerrorasthatwhichexistedduringmachining.Hence,thepositioningerrorinthisstatewouldbeequalto(iG+iT),i.e.(ppDom)/2iG+iT (4)Whenthemachinehascompletelycooleddown,i.e.withoutthermalerror,thedimensionomccanbeobtainedbyon-machinemeasurementusingFTSFQ.Themeasurementhasapositioningerrorequaltothegeometricerrorofthemachineatthelocationofmeasurement.Hence,thepositioningerrorinthisstatewouldbeequalto(i),i.e.(ppDom)/2iG (5)CombiningEqs(4)and(5),thethermallyinducederroriTis(omcom)/2iT (6)Hence,takingEqs(1),(3),and(4)intoaccount,thecutting-force-inducederrorowningtothedeflectionofthemachine–workpiece–toolsystemiFis(omwdes)/2iF (7)Fig.3.Therelationshipsamongdimensions.Sofar,themachiningerroriscomposedofthegeometricerror,thethermalerror,andthecutting-force-inducederrorandcanbeidentifiedusingtheaboveprocedure.Thethermalerrorandtheforce-inducederrormodellingsisaddressedinLi[10].Here,thegeometricerrorofmachinetoolismeasuredandmodelled.5.ModellingofGeometricErrorThegeometricerrorofaworkpieceismainlyaffectedbytheoffsetofthespindle,andthelinearerrorandtheangularerrorsofthecross-slideforatwo-axisCNCturningcentre.Here,onlythegeometricerrorofworkpieceinthex-axisdirectionistakenintoaccountforabarworkpiece.Thisisexpressedbythefollowingformula.iGi(s)€(x)hT-Qix(x) (8)wherei(s)isthespindleoffsetalongthex-axisdirection€(x)istheangularerror(yaw)ofthecross-slideinthex,y-planeix(x)isthelineardisplacementerrorofthecross-slidealongthex-axisdirectionThespindleoffsetisaconstantvalueindependentofthethemachiningposition.Theangularerrortermandthelinearerrortermarefunctionsofthecross-slidepositionx.Inthispaper,theFTSFQismountedonaHitachiSeiiki,HITEC-TURN20SIItwo-axisturningcentre.TheFTSFQcali-brationinstrumentwasdevelopedtomeasurerapidlythedimen-sionoftheworkpieceinthex-axisdirectiononthetwo-axisCNCturningcentrewhenthemachinehascompletelycooleddown,i.e.withouttheeffectofthermalerror.ThegeometricerrorcanbecomputedbyusingEq.(5)accordingtothemeasuredresults.First,thediameterofaprecisiongroundtestbarismeasuredat10positions,20mmapart,byaCMM,theirvaluesppi(i1,2,...,10)arerecorded.Then,thetestbarismountedonthespindle,anditsdiameterisalsomeasuredat10positions,20mmapart,bytheFTSFQ.ThemeasurementarrangementisshowninFig.4,thereadingsareDomcl(i1,2,...,10).Thus,thegeometricerrorateachpointalongthex-axisforthebarworkpiecearecomputedasfollows:iGi(ppiGi)/2 (9)FromstartingpointBtopointA,theresultsareshowninFig.5fordiametersof30,45,60,and75mm.TheworkpieceFig.4.DiagramofthegeometricerrormeasurementoftheworkpieceusingFTSFQ.Fig.5.Geometricerrorsoftheworkpiecealongthez-axis.geometricerrorsinthez-axisdirectionarethesame.Theworkpiecegeometricerrors,however,increasealongthex-axisdirection,asshowninFig.6.Theseaveragegeometricerrorsare—7.1036,—9.0636,—10.7764,—12.5955(urm)fordia-meters30,45,60,and75mm,respectively.Hence,thegeo-metricerrorsofthetwo-axisCNCturningcentrecanbecalculatedbythefollowingEq.:i(x)0.121x3.519 (10)wherexisthediameteroftheworkpiece(mm),i(x)(urm)isthegeometricerroroftheworkpiece.6.CompensationofGeometricErrorTocompensateforthegeometricerrorinthedirectionofthedepthofcut,thetoolpathcanbeshiftedinaccordancewiththeerror.TheNCcommandsinturningaremodified,ataminimumresolution1urm,inthedirectionofthedepthofcut.Thecalculatedgeometricerrorexceeded1urmaccordingtotheequation(10),asillustratedinFig7.Figure8showsthattheworkpieceerrorsincludethegeo-metricerror,thethermalerrorandthecuttingforceerror.Thetoolpathdeterminedbythecalculatedgeometricerror,andtheworkpieceerrorarecompensatedforbythemodifiedNCcommandmethod.Inthisexample,weusedacuttingspeedof4ms—,afeedrateof0.2mmre—1,adepthofcutofFig.6.TheaveragegeometricerrorforthedifferentdiametersFig.7.Compensationofgeometricerror.Fig.8.CompensationofgeometricerrorbyamodifiedNCcommand.1mm(cuttinglength100mm),adiameterof40mm,mildsteelworkpieces,andDNMG150604QMtools.Thework-pieceerrorwasmeasuredusingourFTSFQat10positions10mmapart.Theworkpieceerrorswerereducedbymeansofthecompensationofthegeometricerror.Theremainingwork-pieceerrorcontainsthethermalerrorandcuttingforceerror,thesewillbediscussedinpart2[10]andpart4[11].Experi-mentalresultssuggestthatthegeometricerrorinfinishturningcanbecompensatedforbytheuseofthissimplemethoddescribedabove.7.ConclusionsOwingtoincreasingdemandforhigherprecisioncoupledwithlowercostsinthemachiningindustry,thereisagrowingneedforautomatedtechniquesleadingtoenhancedmachiningaccuracy.Inthispaper,theworkpieceerrorsourcesareana-lysedforatwo-axisCNCturningcentre,whichderivemainlyfromthegeometricerrorofthemachinetool,thethermallyinducederror,andtheerrorarisingfromMFWTsystemdeflec-tioninducedbythecuttingforces.Asimpleandlow-costmeasuringsystemcombiningafinetouchsensorandQ-setterformachinetools(FTSFQ)isdevelopedtomeasurethework-pieceerroron-machine.Theworkpieceerrorscanbedividedintothegeometricerror,thethermalerror,andthecuttingforceerrorfromtheon-machineandpost-processmeasuredresults.Thegeometricerrorfunctionofatwo-axisCNCturningcentrecanbeestablishedrapidlyfromthemeasurementsbyusingtheFTSFQandaCMM.ExperimentalresultsshowthegeometricerrorcanbecompensatedforbythemodifyingtheNCcommandsinfinishturning.References1.T.Asao,Y.MizugakiandM.Sakamoto,“Precisionturningbymeansofasimplifiedpredictivefunctionofmachiningerror”,AnnalsCIRP,41(1),pp.447–451,1992.2.JingxiaYuanandJunNi,“Thereal-timeerrorcompensationtechniqueforCNCmachiningsystems”,Mechatronics,8(4),pp.359–380,1998.3.Sung-GwangChen,A.GalipUlsoyandYoramKoren,“Errorsourcediagnosticusingaturningprocesssimulator”,TransactionsASMEJournalofManufacturingScienceandEngineering,120,pp.409–416,1998.4.V.S.B.KiridenaandP.M.Ferreira,“Modelingandestimationofquasistaticmachine-toolerror”,TransactionsNAMRI/SME,pp.211–221,1991.5.Y.Koren,ComputerControlofManufacturingSystems,McGraw-Hill,1983.6.Y.KorenandC.C.Lo,“Advancedcontrollersforfeeddrives”,AnnalsCIRP,41(2),pp.689–698,1992.7.V.Ostafiev,I.MasolandG.Timchik,“Multiparametersintelligentmonitoringsystemforturning”,ProceedingsofSMEInternationalConference,LasVegas,Nevada,pp.296–300,1991.8.V.A.OstafievandPatriK.Venuvinod,“Anewelectromagneticcontactsensingtechniqueforenhancingmachiningaccuracy”.IMECE-97,ASME,1997.9.Z.Q.LiuandPatriK.Venuvinod,“ErrorcompensationinCNCturningsolelyfromdimensionalmeasurementsofpreviouslymachinedparts”,AnnalsCIRP,48(1),pp.429–432,1999.10.X.Li,“Real-timePredictionofworkpieceerrorsforaCNCturningcentre.Part2.Modellingandestimationofthermallyinducederrors”,InternationalJournalofAdvancedManufacturingTechnology,2000.11.X.Li,“Real-timepredictionofworkpieceerrorsforaCNCturningcentre.Part4.Cutting-force-inducederrors”,InternationalJournalofAdvancedManufacturingTechnology,2000.期刊或雜志名：IntJAdvManufTechnol出版社：Springer-VerlagLondonLimited出版時(shí)間：2001數(shù)控車削中心工件誤差實(shí)時(shí)預(yù)報(bào)第1部分：測(cè)量和鑒定李小俚制造工程系，香港城市大學(xué)，香港本文分析了工件在加工旋轉(zhuǎn)時(shí)的誤差來源，其中主要來自機(jī)加工工具的幾何誤差，即熱誤差，該誤差產(chǎn)生于機(jī)加工工件的切削力引起的刀具系統(tǒng)的偏轉(zhuǎn)。一個(gè)簡(jiǎn)單和低成本的緊湊型測(cè)量系統(tǒng)相結(jié)合的靈敏的觸摸傳感器的工具（FTS-Q）產(chǎn)生了，并應(yīng)用于測(cè)量工件表面.并且還介紹了一種識(shí)別工件誤差的方法。工件的誤差是由幾何誤差，熱誤差組成的，而切屑力誤差根據(jù)每一步的測(cè)量結(jié)果是可以確定的。幾何誤差由建立在快速的基礎(chǔ)上的兩軸CNC車削中心模型測(cè)量，測(cè)量結(jié)果由坐標(biāo)測(cè)量機(jī)（CMM）用FTS-Q的方法顯示出來。實(shí)驗(yàn)結(jié)果表明，在工具旋轉(zhuǎn)時(shí)，通過修改數(shù)控指令，這種幾何誤差可以得到補(bǔ)償。關(guān)鍵詞：尺寸測(cè)量;錯(cuò)誤辨識(shí);幾何誤差;旋轉(zhuǎn)導(dǎo)言近年來，超精密加工已取得了顯著進(jìn)展，一些特殊的車床已能作出超一般的機(jī)械加工，實(shí)現(xiàn)了不到1微米，甚至有實(shí)現(xiàn)超微米的可能性。而實(shí)現(xiàn)這種可能公用的一種方法是在開機(jī)后用高水平的三維來實(shí)現(xiàn)磨削的準(zhǔn)確性。然而，有些切削工具（如鉆石）和一些工件（如鋁）應(yīng)限制應(yīng)用超精密車床。第二種實(shí)現(xiàn)的方法是增加機(jī)床數(shù)目的加工工藝，但是這將導(dǎo)致制造成本的增加。

目前，我國(guó)大部分CNC車床配備定位達(dá)到了1微米。然而，在完成車削時(shí)，各種加工誤差的準(zhǔn)確性應(yīng)以某種程度的降低約10微米，所以，當(dāng)談到碳鋼時(shí)，加工誤差可以預(yù)見超出20-30微米。為提高加工的準(zhǔn)確性，這種精心設(shè)計(jì)的方法和制造已被廣泛應(yīng)用于一些CNC車床。然而按以上方法制造精度要求系統(tǒng)超出一般水平的機(jī)床時(shí)，生產(chǎn)的成本將會(huì)迅速的增加。為了進(jìn)一步改善提高機(jī)床精度的效益成本，實(shí)時(shí)的誤差預(yù)報(bào)以及基于傳感的補(bǔ)償建模與控制技術(shù)已得到了廣泛的研究，因此，超精密的加工校正，可以安排在一般的CNC車床。定位解決了刀具和工件的切削，但它不能保證高度的準(zhǔn)確性，因?yàn)樵诩庸ぶ校邢髁?huì)影響機(jī)床-工件-刀具系統(tǒng)，并且熱也會(huì)導(dǎo)致誤差等。一般來說，定位裝置采用壓電激勵(lì)器，用于改善工作的準(zhǔn)確性，但是，采用這種方法也帶來了一些問題，例如反饋系統(tǒng)和精度傳感器，這些都會(huì)增加制造產(chǎn)品的成本。但是如果工件的誤差可以用測(cè)量?jī)x器測(cè)量，或者利用模型可以提前預(yù)知，再執(zhí)行已經(jīng)做好的修飾數(shù)控命令，那么將會(huì)充分利用好數(shù)控機(jī)床。因此，在一定時(shí)間內(nèi)，這種數(shù)控車削中心可以補(bǔ)償一般的加工誤差，即這種機(jī)床采用可改性數(shù)控命令能制造出具有高水平精確度的產(chǎn)品。工件的誤差來自刀具和工件的實(shí)際相對(duì)運(yùn)動(dòng)與理想相對(duì)運(yùn)動(dòng)的誤差。如果是雙軸車削中心，由于車削條件不同，導(dǎo)致相對(duì)誤差各不相同，如機(jī)床刀具的時(shí)變產(chǎn)生熱偏轉(zhuǎn)，導(dǎo)致不同的熱誤差。根據(jù)工件各種不同誤差來源，工件誤差可分為幾何誤差，熱誤差，以及切削疲憊誤差。主要影響因素包括：組成機(jī)床部分的位置錯(cuò)誤和機(jī)械結(jié)構(gòu)的角錯(cuò)誤，即幾何誤差。這種由于切削力產(chǎn)生的機(jī)床熱誤差（即熱誤差），和影響的加工系統(tǒng)（包括機(jī)床，工件和刀具），被稱為切力誤差。本文分析了工件在加工旋轉(zhuǎn)時(shí)誤差的來源：數(shù)控機(jī)床的幾何誤差，熱誤差，切削力產(chǎn)生的機(jī)械工件和刀具系統(tǒng)的偏離誤差。一個(gè)簡(jiǎn)單而低成本的測(cè)量?jī)x器，它具有良好的觸摸傳感器和機(jī)床的FTSF-Q裝置，能描述工件的尺寸，并用于測(cè)量工件的誤差。已經(jīng)有一種新的方法來確定幾何誤差，熱誤差，并且能夠回饋切力誤差到兩軸車削中心。最后，數(shù)控車削中心的造型幾何誤差由FTSF-Q和CMM來測(cè)定。這種幾何誤差可以由改進(jìn)的數(shù)控指揮得到補(bǔ)償。2.車削加工中的誤差來源機(jī)床系統(tǒng)是由驅(qū)動(dòng)伺服，機(jī)床結(jié)構(gòu)，工件和切削過程組成。主要誤差源來自機(jī)床（熱誤差，幾何誤差，和強(qiáng)迫振動(dòng)），控制（伺服驅(qū)動(dòng)器動(dòng)力學(xué)及編程錯(cuò)誤），以及切割進(jìn)程（機(jī)床及刀具偏轉(zhuǎn)，工件偏轉(zhuǎn)，刀具磨損和顫振）。其中對(duì)加工的準(zhǔn)確性占主導(dǎo)地位的誤差來自機(jī)床，包括熱誤差（機(jī)床熱誤差和工件的熱誤差），幾何誤差和強(qiáng)迫振動(dòng)。在加工精細(xì)工件時(shí)熱誤差和幾何誤差是主要的影響因素。然而，機(jī)床誤差不同與其他誤差來源，它可以得到補(bǔ)償。均衡動(dòng)態(tài)部件以及隔離振動(dòng)可以減少由誤差衍生來的強(qiáng)迫振動(dòng)?？刂破骱万?qū)動(dòng)器的誤差來自切削力的干擾和機(jī)座的慣性，這些誤差可能減少一個(gè)接一個(gè)減速器的功能，或者一個(gè)先進(jìn)的伺服驅(qū)動(dòng)控制器，這些誤差，相對(duì)于其他誤差來源，利用上述方法可以在他們較小時(shí)得到減少。由于需求大，生產(chǎn)率高，等級(jí)要求自由和大深度的削減要求，而導(dǎo)致產(chǎn)生較大切削力。因此，割力誘導(dǎo)撓度來自機(jī)床（主軸），刀柄，工件，并且刀具在加工精度切削過程起了重要作用。此外，在切削過程，刀具磨損和機(jī)床顫振，亦是重要的誤差來源。不過，這些影響可以忽略，所以在這里把焦點(diǎn)放在主要誤差來源?？傊?，加工一個(gè)工件的誤差，即總加工誤差()，主要由機(jī)床幾何誤差(),熱誤差(),以及由切削力所產(chǎn)生的機(jī)床-工件-刀具系統(tǒng)的撓度誘導(dǎo)誤差()組成，故：≈++(1)在下一節(jié)中，我們提出一個(gè)新的緊湊型測(cè)量?jī)x器和新的分析方法來衡量和確定工件的旋轉(zhuǎn)誤差。3.緊湊型測(cè)量系統(tǒng)接觸傳感器，例如觸摸觸發(fā)探針，已用于測(cè)量工件尺寸加工。在加工實(shí)踐中，測(cè)量?jī)x器是附在機(jī)器其中的軸，以衡量一個(gè)工件的表面。一種tp7m或是MP3與ph10m各種機(jī)動(dòng)探頭元件或ph6m固定頭由于其高的可靠性和準(zhǔn)確性以及完整的加工點(diǎn)，廣泛應(yīng)用于自動(dòng)化數(shù)控視察環(huán)境。雖然該探頭有足夠的精確度（針式特有的單項(xiàng)重復(fù)性（高靈敏度）：0.25微米;提前可設(shè)定的旋轉(zhuǎn)360（高靈敏度）：0.25微米），并且可進(jìn)行多種功能，他們也有明顯的缺點(diǎn)，例如制造的復(fù)雜性，高價(jià)格（4988美元），以及復(fù)雜的維修。為了克服這些缺點(diǎn)，Ostafiev等人介紹了一種技術(shù)并以此設(shè)計(jì)了一個(gè)良好的觸摸傳感器：觸摸觸發(fā)探頭，該傳感器刀具本身就作為探針。該傳感器的測(cè)量精度是當(dāng)年觸摸觸發(fā)探頭最好的。此外練習(xí)使用這種傳感器是非常簡(jiǎn)單的，制造成本很低，而且維修保養(yǎng)是非常容易的。在本文中這個(gè)傳感器將作為Q裝置來測(cè)量工件直徑等一些相關(guān)的問題。觸摸感應(yīng)器應(yīng)安裝在一個(gè)數(shù)控車削中心上。作為數(shù)控單元，當(dāng)我們手動(dòng)把刀尖觸碰到主軸時(shí)，它會(huì)產(chǎn)生中斷信號(hào)。此外，它可以記錄一個(gè)工件自動(dòng)轉(zhuǎn)向的坐標(biāo)。這種功能方便隨時(shí)更換刀具。因此，擁有這種功能稱為“快速換刀裝置”或“Q裝置”。基于上述原則，我們可以設(shè)計(jì)一個(gè)由良好的觸摸傳感器構(gòu)成的開關(guān)，控制Q裝置和NC單元。當(dāng)?shù)都庥|及工件表面，精細(xì)式觸摸傳感器能發(fā)出一個(gè)控制信號(hào)轉(zhuǎn)換，使之向"關(guān)閉"狀態(tài)。見圖1。優(yōu)良式觸摸傳感器取代了問答式的Q裝置功能，以防止軸在記錄的工件坐標(biāo)間偏移。圖1觸摸傳感器固定在一個(gè)CNC控制器的流程圖因此，優(yōu)良的觸摸傳感器如圖1，流程圖的數(shù)據(jù)由觸摸傳感器即固定的Q裝置(FTSFQ)測(cè)得，可以用來檢查工件直徑，該方法是圖2.當(dāng)?shù)毒呒舛擞|及工件表面時(shí)，將發(fā)出“嗶嗶”的聲音，這是開關(guān)的“關(guān)”的信號(hào)，主軸將根據(jù)Q裝置自動(dòng)停止。一個(gè)新的“刀具補(bǔ)償”將由NC單元提供（展示數(shù)控）。在觸及工件表面前，刀具尖端觸及Q裝置以及“刀具補(bǔ)償”就已經(jīng)獲得。因此，對(duì)于工件直徑有下列關(guān)系：=2H+(2)其中：：刀具切削時(shí)Q裝置提供的刀具補(bǔ)償；：刀具觸及工件表面時(shí)的刀具補(bǔ)償；H是Q裝置在X軸方向上離主軸的距離。這由機(jī)床制造商提供，如Seiki-SeicosLII旋轉(zhuǎn)中心，它是85.356毫米。Ostafiev和Venuvinod兩款觸摸傳感器在測(cè)試測(cè)量精度時(shí)，在演示機(jī)上能夠測(cè)量精度在0.01微米以下的精度條件。然而，優(yōu)良的觸摸傳感器在測(cè)量精度時(shí)獲得的精度為微米，因?yàn)闇y(cè)量結(jié)果在系統(tǒng)中顯示出來時(shí)，數(shù)控系統(tǒng)和讀數(shù)精度系統(tǒng)最大是1微米。4.確定工件的錯(cuò)誤上述分析中工件的誤差源的總誤差主要由以下在加工零件車削操作中的誤差組成：：的機(jī)床的幾何誤差。：熱引起的錯(cuò)誤。：切削力引起誤差。圖2使用Q-setter的機(jī)床利用優(yōu)良的觸摸傳感器對(duì)工件的直徑進(jìn)行檢查要分析一個(gè)加工工件的誤差源，劉＆Venuvinod。圖3用來說明在車削時(shí)不同的誤差分量之間的尺寸關(guān)系。另外，在圖3中，是所希望的工件尺寸;是在測(cè)量使用FTSFQ加工操作后立即獲得的維度;是在機(jī)床FTSFQ加工操作后冷卻下來測(cè)量獲得的尺寸，使用三坐標(biāo)測(cè)量機(jī)測(cè)量已經(jīng)從機(jī)器上取下的工件通過處理后獲得的尺寸。當(dāng)工件被加工時(shí)，機(jī)床系統(tǒng)中使用CMM的尺寸進(jìn)行檢查。此過程被稱為后工序檢驗(yàn)，由于CMM的定位誤差比所需的測(cè)量精度更小，總誤差是：=(-)/2 (3)通過以上獲得的尺寸，使用FTSFQ測(cè)量后立即加工，即機(jī)器在加工時(shí)仍然在相同的熱狀態(tài)。測(cè)量時(shí)，在加工過程中具有相同的定位誤差。因此，在該狀態(tài)下的定位誤差將等于(+)，i.e.(—)/2=+(4)當(dāng)機(jī)器完全冷卻下來，即無熱誤差時(shí)，尺寸可以通過FTSFQ測(cè)量。測(cè)量等于測(cè)量的位置處機(jī)器具有的幾何誤差的定位誤差。因此，在該狀態(tài)下的定位誤差將是（），即等于()/2= (5)結(jié)合式（4）和（5），熱誘導(dǎo)的錯(cuò)誤，它是()/2= (6)故，以式（1），（3）和（4）考慮到，如果是機(jī)器的工件的刀具系統(tǒng)偏轉(zhuǎn)切割力引起的誤差，是：(-)/2= (7)圖3維之間的關(guān)系到目前為止，由加工誤差的幾何誤差，熱誤差和切割力引起的誤差，可以使用上述步驟來識(shí)別。這里，機(jī)床的幾何誤差的測(cè)量和模擬解決熱誤差和力引起的錯(cuò)誤構(gòu)模。5.模型的幾何誤差兩軸CNC車削中心滑動(dòng)、主軸偏移的工件的幾何誤差主要由線性誤差和角度誤差交叉的影響。這里，僅在x軸方向上的工件的幾何誤差是由以下結(jié)構(gòu)式表示：=—€(x)－ (8)其中：：十字滑塊在x，y平面沿x軸方向€(x)的偏移量是主軸的轉(zhuǎn)角誤差；：十字滑塊沿x軸方向的線性位移誤差；獨(dú)立的加工位置主軸偏移量是一個(gè)恒定值，轉(zhuǎn)角誤差項(xiàng)和線性誤差項(xiàng)是十字滑塊的位置x的函數(shù)。在本文中，國(guó)際展貿(mào)中心將FTSFQ安裝在日立Seiiki開發(fā)的FTSFQ校準(zhǔn)儀器上，用來進(jìn)行20SII兩軸車削加工中心快速測(cè)量工件中的x軸方向上的兩軸CNC車削中心，當(dāng)該裝置已經(jīng)完全冷卻下來的維