外文翻译--数控车削中心工件误差实时预报 英文版.pdf

INTJADVMANUFTECHNOL200117649–6532001SPRINGERVERLAGLONDONLIMITEDREALTIMEPREDICTIONOFWORKPIECEERRORSFORACNCTURNINGCENTRE,PART1MEASUREMENTANDIDENTIFICATIONXLIDEPARTMENTOFMANUFACTURINGENGINEERING,CITYUNIVERSITYOFHONGKONG,HONGKONGTHISPAPERANALYSESTHEERRORSOURCESOFTHEWORKPIECEINBARTURNING,WHICHMAINLYDERIVEFROMTHEGEOMETRICERROROFMACHINETOOLS,IETHETHERMALLYINDUCEDERROR,THEERRORARISINGFROMMACHINE–WORKPIECE–TOOLSYSTEMDEFLECTIONINDUCEDBYTHECUTTINGFORCESASIMPLEANDLOWCOSTCOMPACTMEASURINGSYSTEMCOMBININGAFINETOUCHSENSORANDQSETTEROFMACHINETOOLSFTSFQISDEVELOPED,ANDAPPLIEDTOMEASURETHEWORKPIECEDIMENSIONSANIDENTIFICATIONMETHODFORWORKPIECEERRORSISALSOPRESENTEDTHEWORKPIECEERRORSWHICHARECOMPOSEDOFTHEGEOMETRICERROR,THERMALERROR,ANDCUTTINGFORCEERRORCANBEIDENTIFIEDACCORDINGTOTHEMEASUREMENTRESULTSOFEACHSTEPTHEMODELOFTHEGEOMETRICERROROFATWOAXISCNCTURNINGCENTREISESTABLISHEDRAPIDLYBASEDONTHEMEASUREMENTRESULTSBYUSINGANFTSFQSETTERANDCOORDINATEMEASURINGMACHINECMMEXPERIMENTALRESULTSSHOWTHATTHEGEOMETRICERRORCANBECOMPENSATEDBYMODIFIEDNCCOMMANDSINBARTURNINGKEYWORDSDIMENSIONMEASURE；ERRORIDENTIFICATION；GEOMETRICERROR；TURNING1INTRODUCTIONINRECENTYEARS,ULTRAPRECISIONMACHININGHASMADEREMARKABLEPROGRESSSOMESPECIALLATHESHAVEBEENABLETOMAKEULTRAPRECISIONMACHINING,TOLESSTHANASUBMICRONANDNANOMICRONTOLERANCESAPOSSIBILITYACOMMONSECONDAPPROACHISTHATTHEGRINDINGISUSEDTOACHIEVEAHIGHLEVELOFDIMENSIONALACCURACYAFTERTURNINGHOWEVER,THECONDITIONOFTHECUTTINGTOOLDIAMONDANDWORKPIECEALUMINIUMHAVERESTRICTEDTHEAPPLICATIONOFULTRAPRECISIONLATHESTHESECONDAPPROACHINCREASESTHENUMBEROFMACHINETOOLSANDMACHININGPROCESSESUSED1,WHICHRESULTSINANINCREASEINTHEMANUFACTURINGCOSTATPRESENT,MOSTCNCLATHESAREEQUIPPEDWITHAPOSITIONINGRESOLUTIONOF1MMVARIOUSMACHININGERRORSINFINISHTURNING,HOWEVER,DEGRADETHEACCURACYTOALEVELOFAPPROXIMATELYCORRESPONDENCEANDOFFPRINTREQUESTSTODRXIAOLILI,DEPARTMENTOFMANUFACTURINGENGINEERING,CITYUNIVERSITYOFHONGKONG,HONGKONGEMAILLIXIAOLIFHITYAHOOCOM10MM,SOTHATWHENTURNINGCARBONSTEEL,AMACHININGERRORPREDICTABLYARISESINEXCESSOF20–30MMFORIMPROVINGMACHININGACCURACY,THEMETHODOFCAREFULDESIGNANDMANUFACTUREHASBEENEXTENSIVELYUSEDINSOMECNCLATHESHOWEVER,THEMANUFACTURINGCOSTBASEDONTHEABOVEMETHODWILLRAPIDLYINCREASEWHENTHEACCURACYREQUIREMENTSOFTHEMACHINETOOLSYSTEMAREINCREASEDBEYONDACERTAINLEVELFORFURTHERIMPROVINGMACHINEACCURACYCOSTEFFECTIVELY,REALTIMEERRORPREDICTIONANDCOMPENSATIONBASEDONSENSING,MODELLINGANDCONTROLTECHNIQUESHAVEBEENWIDELYSTUDIED2,SOULTRAPRECISIONANDFINISHTUNINGCANBEPERFORMEDONONECNCLATHETHEPOSITIONINGRESOLUTIONOFTHECUTTINGTOOLSANDWORKPIECEISREDUCEDSOTHATITCANNOTMAINTAINHIGHACCURACYDURINGMACHININGBECAUSEOFTHECUTTINGFORCEINDUCEDDEFLECTIONOFTHEMACHINE–WORKPIECE–TOOLSYSTEM,ANDTHETHERMALLYINDUCEDERROR,ETCINGENERAL,APOSITIONINGDEVICEUSINGAPIEZOELETRICACTUATORISUSEDTOIMPROVETHEWORKINGACCURACY,BUTTHEMETHODINTRODUCESSOMEPROBLEMS,SUCHAS,THEFEEDBACKSTRATEGY,ANDTHEACCURACYOFSENSORS,WHICHADDTOTHEMANUFACTURINGCOSTOFTHEPRODUCTSHOWEVER,IFTHEWORKPIECEERRORCANBEMEASUREDBYUSINGAMEASURINGINSTRUMENT,ORPREDICTEDBYUSINGAMODELLING,THETURNINGPROGRAMPRODUCEDBYMODIFIEDNCCOMMANDSCANBEEXECUTEDSATISFACTORILYONACNCMACHINETOOLTHUS,ACNCTURNINGCENTRECANCOMPENSATEFORTHENORMALMACHININGERROR,IETHEMACHINETOOLCANMACHINEAPRODUCTWITHAHIGHLEVELOFACCURACYUSINGMODIFIEDNCCOMMANDS,INREALTIMETHEWORKPIECEERRORDERIVESFROMTHEERRORINTHERELATIVEMOVEMENTBETWEENTHECUTTINGTOOLANDTHEIDEALWORKPIECEFORATWOAXISTURNINGCENTRE,THISRELATIVEERRORVARIESASTHECONDITIONOFTHECUTTINGPROGRESSES,EGTHETHERMALDEFLECTIONOFTHEMACHINETOOLISTIMEVARIANT,WHICHRESULTSINDIFFERENTTHERMALERRORSACCORDINGTOTHEVARIOUSCHARACTERSOFTHEERRORSOURCESOFTHEWORKPIECE,THEWORKPIECEERRORSCANBECLASSIFIEDASGEOMETRICERROR,THERMALLYINDUCEDERROR,ANDCUTTINGFORCEINDUCEDERRORTHEMAINAFFECTINGFACTORSINCLUDETHEPOSITIONERRORSOFTHECOMPONENTSOFTHEMACHINETOOLANDTHEANGULARERRORSOFTHEMACHINESTRUCTURE,IETHEGEOMETRICERRORTHETHERMALLYINDUCEDERRORSOFTHEMACHINETOOLIETHETHERMALERROR,ANDTHEDEFLECTIONOFTHEMACHININGSYSTEMINCLUDINGTHEMACHINETOOLS,WORKPIECE,ANDCUTTINGTOOLSARISINGFROMCUTTINGFORCES,ARECALLEDTHECUTTINGFORCEERROR650XLITHISPAPERANALYSESTHEWORKPIECEERRORSOURCESINTURNINGTHEERRORSOFAMACHINEDWORKPIECEAREMAINLYCOMPOSEDOFTHEGEOMETRICERROROFTHEMACHINETOOLS,THETHERMALLYINDUCEDERROR,ANDTHEERRORARISINGFROMMACHINE–WORKPIECE–TOOLSYSTEMDEFLECTIONINDUCEDBYTHECUTTINGFORCESASIMPLEANDLOWCOSTMEASURINGINSTRUMENTFORTHEWORKPIECEDIMENSIONS,WHICHCOMBINESAFINETOUCHSENSORANDMACHINETOOLQSETTERFTSFQ,ISDESCRIBED,ANDAPPLIEDTOMEASURETHEWORKPIECEERRORANEWMETHODFORIDENTIFYINGTHEGEOMETRICERROR,THETHERMALERROR,ANDTHECUTTINGFORCEERRORISALSOPRESENTEDFORATWOAXISTURNINGCENTREFINALLY,THEMODELLINGOFTHEGEOMETRICERROROFACNCTURNINGCENTREISPRESENTED,BASEDONTHEMEASUREMENTRESULTSUSINGTHEFTSFQANDCMMTHEGEOMETRICERRORCANBECOMPENSATEDBYTHEMODIFIEDNCCOMMANDMETHOD2ERRORSOURCESINTURNINGTHEMACHINETOOLSYSTEMISCOMPOSEDOFTHEDRIVESERVO,THEMACHINETOOLSTRUCTURE,THEWORKPIECEANDTHECUTTINGPROCESSTHEMAJORERRORSOURCESDERIVEFROMTHEMACHINETOOLTHERMALERRORS,GEOMETRICERRORS,ANDFORCEDVIBRATIONS,THECONTROLDRIVESERVODYNAMICSANDPROGRAMMINGERRORSANDTHECUTTI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