外文翻译--新型直动式压电电液伺服阀复合控制方法.doc

附二:外文翻译HighPreciseControlMethodforaNewTypeofPiezoelectricElectrohydraulicServoValveAbstract：Anewtypeofpiezoelectricelectro-hydraulicservovalvesystemwasproposedAndthenmultilayerpiezoelectricactuatorbasedonnewpiezoelectricceramicmaterialwasusedastheelectricity-machineconverteroftheproposedpiezoelectricelectro-hydraulicservovalve.Theproposedpiezoelectricelectro-hydraulicservovalvehasascendantperformancecomparedwithconventionalones.Butthesystemisofhighnonlinearityanduncertainty,itcannotachievefavorablecontrolperformancebyconventionalcontrolmethodTodevelopanefficientwaytocontrolpiezoelectricelectrohydraulicservovalvesystemAhighprecisefuzzycontrolmethodwithhysteresisnonlinearmodelinfeedforwardloopwasproposed.Thecontrolmethodisseparatedintotwoparts：afeedforwardloopwithPreisachhysteresisnonlinearmodelandafeedbackloopwithhigh-precisefuzzycontro1.ExperimentalresultsshowthatthehysteresisloopandthemaximumoutputhysteresisbythePIDcontrolmethodare4.22and211pm,respectively；thehysteresisloopandthemaximumoutputhysteresisbytheproposedcontrolmethodrespectivelyare074and037m，respectively；themaximumtrackingerrorbythePIDcontrolmethodforsinewavereferencesignalisabout502,themaximumtrackingerrorbytheproposedcontrolmethodforsinewavereferencesignalisabout085contro1Keywords：piezoelectricelectrohydraulicservovalve；hysteresisnonlinearity；Preisachmodel；fuzzycontrol1IntroductionElectrohydraulicservosystemiswidelyappliedinindustrialdomainnowadaysforexamplerobotdrive，machinebuilding,architecturalengineeringTheelectro-hydraulicservovalveisthekerneloftheelectro-hydraulicservosystem,anditsperformancehasdecisiveeffectOfthewholesystemTheconventionaldrivemodeofelectrohydraulicservovalvehaslowerresolutionandnarrowerworkbandwidth，whichrestrictstheapplicationsoftheelectro-hydraulicservovalveTheproposedpiezoelectricelectro-hydraulicservovalveadoptsmultilayerpiezoelectricactuatoraselectricity-machineconverter.ThisHewtypeofpiezoelectricelectro-hydraulicservovalvehasbetterdynamicperformancethanthatofconventionalonesAtpresent，withtheresearchandthedevelopmentofnew-typeactuatorbasedonnewtypematerials,itispossibletomakethenewelectricity-machineconverterwithhighfrequency.Newmaterialsincludepiezoelectricceramicmaterials,magnetostrjctivematerials,shapememoryalloysThereinto,multilayerpiezoelectricactuatorsbasedonnewpiezoelectricceramicmaterialshavemanymeritssuchassmallcubage，highresolution，highfrequencyandlargedriveforceHence，theyarewidelyusedinthemicro-positiondeviceofmachinetoolsandotherprecisionmachines1-6However,theyalsohavemanyshortcomings，for毕业设计（论文）第页1example，hysteresisnonlinearitymodelinfeedforwardloopwasproposed2Workprincipleandcharacteristicofnew-typeofpiezoelectricelectro-hydraulicValveBecausethepullingforcecapacityofmultilayerpiezoelectricactuatorisverypoor,itcannotmaketheslidevalveoftheelectro,hydraulicservovalvebidirectionallvmove.Twomultilayerpiezoelectricactuatorswereadoptedtosolvethisproblem7-8.Theshortcomingofthismethodishighcostandsystemisdifficulttocontro1.Utilizingtherestoringforceofaleafspring，onemultilayerpiezoelectricactuatorcanrealizebidirectionalmovementoftheslidevalveinthispaper.Whenthevoltageimposedonmultilayerpiezoelectricactuator1sincreased，multilayerpiezoelectricactuatorwillelongateanddrivetheslidevalvetomovetowardstheleft，whichmakestheleafspringdeformOnthecontrary,whenthevoltageimposedonmultilayerpiezoelectricactuatorisreduced，multilayerpiezoelectricactuatorwillbeshortenedandthendrivetheslidevalvemovetowardstherightbytheactionoftherestoringforceoftheleafspring.ThestructureofnewtypeofpiezoelectricelectrohydraulicservovalveisshowninFig1Theinput-outputcharacteristicofthenewtypeofpiezoelectricelectro-hydraulicservovalvesystemindicatesthatithashysteresisnonlinearitywithnonloca1memory(seeFig2).AtanyreachablepointL(Ua，Ya)ininput-outputdiagram，thenumberofalternativecurvethatdescribesthefuturepathofhysteresisnonlinearitywithnonloca1memoryisinfinite.Namely,thefutureoutputofthesystemdependsnotonlyonthecurrentoutputYaandfutureinput，butalsoonthepasthistoryofinputvaluesextremum.Hence,theoutputresponseofnewtypeofpiezoelectricelectro-hydraulicservovalvetoanappliedinputvoltagebecomesunpredictable.Inthesystem，thereexistothernonlinearitiessuchasforceoffrictionandworkdeadzoneofvalve,furthermore，dampingcoefficientandoiltemperaturearealsochangedwithtimeThenonlinearityanduncertaintyhaveseriouslyeffectsonthepositionprecision.Toimprovetheperformanceofthenewtypeofpiezoelectricelectro-hydraulicservovalvesystem,avalidcontrolmethodisneeded3ControlalgorithmAtpresent,conventionalPIDcontrolleriswidelyappliedinindustrialcontroldomainbecauseofitssimplecontrolstructure,easydesignandinexpensivecostHowever,conventionalPIDcontrollerisdifficulttoachievegoodcontrolperformanceinthenewtypeofpiezoelectricelectro,hydraulicservovalvesystembecausethecontrolobjecthashigh毕业设计（论文）第页2nonlinearityanduncertaintyFuzzycontrollershowsgoodresultsinthecaseofcontrollinghighnonlinearsystems.However,conventionalfuzzycontrollerisessentiallyakindofnonlinearPDcontroller,thereexistssteadystateerror,whichcannotmeetthedemandofhighpreciseofthesystemInthispaper,ahigh-precisefuzzycontrolalgorithmwithPreisachhysteresisnonlinearmodelinfeedforwardloopwasproposedTheblockdiagramofthecombinedcontrolisshowninFig3ThecontrolsystemiscomposedofafeedforwardloopbasedonPreisachmodelandafeedbackloopofhighprecisefuzzycontrollerUl(istheoutputoffeedforwardloopbasedonPreisachmode1Asalinearterm,itisselectedfromaPreisachfunctiontablebasedonthegivenpositionvalueU2(istheoutputofthehighprecisefuzzycontrollerThesumU(t)offeedforwardcontrolvoltagefandfeedbackcontrolvoltageU2(t)，asultimatecontrolvoltage，isactedonnewtypepiezoelectricelectro-hydraulicservovalve.31FeedforwardloopbasedonPreisachmodelTheopenloopresponseofthenewtypepiezoelectricelectro-hydraulicservovalvesystemunderanarbitraryandnon-cyclicinputsignalisshowninFig2Thisphenomenonappearsashysteresisnonlinearitywithnonlocalmemory,whichcanbepredictedbyPreisachmode1ThenumericalformofPreisachmodelcanbewrittenasfoliows：ddtuutfS)(),()(1)Eqn.(1)canbeusedtocalculatetheresponseofthenewtypeofpiezoelectricelectro-hydraulicservovalvesubjecttoaknownarbitraryinputvoltagesequenceAseriesoffirstorderfunctionskkrofthenewtypeofpiezoelectricelectro-hydraulicservovalveareexperimentallydeterminedTheprocedureisasfollowsThespacebetweenzeroandsaturationvoltageUsisdividedintonequipartitions,andthevoltageofeveryequantpointiskUsn，wherek=-0，1，2，nVoltageisappliedfromzerotoeveryequantpointkUsn，andthendecreasedtozeroInthisprocess，thepositionoutputvaluesofthenewtypeofpiezoelectricelectro-hydraulicservovalvearerecordedateveryequantpointbetweenzeroandsaturationvoltageUs，therewith，kkrandthePreisachfunctiontableareobtained(seeFig4)，毕业设计（论文）第页3ddtuddutfStu)(),()(（2）Basedonthedrivervoltagerangeofthenewtypeofpiezoelectricelectrohydraulicservovalve，thecoordinatespaceisselectedas0Ul50Vand0U<150VFromFig4，thelimittriangleisdividedintoseveralsquaresandtrianglesDecreasingthesizeofthesquaresandtrianglesisexpectedtoincreasetheaccuracyofthemode1,however,itwillspendmassivecomputationaltimeBasedontheexperiments,nisselectedas5，namely,thesizeofeachofsidesofthesquaresandtrianglesisselectedas30V.BasedonthegivenpositionvalueandthenumericalformofthePreisachmodel，1)(nUtUor)(tUncanbeobtainedThereby,basedonPreisachfunctiontable，thecontrolvoltageUl(t)isobtainedwhen1nUliesontheverticallineorUliesonthehorizontallineFortheinexistencevoltageinthePreisachfunctiontableitcanbeobtainedbythelinearinterpolationIncomparisontoaconventionalfeedbackcontroller,themainadvantageofthismode1-basedfeedforwardcontrolleristhatitcancompensatethehysteresisnonlinearityofthesystemandachievehighlydynamicoperationatthesametime,andnoadditionalsensorisneededThisleadstoaverysimpleandinexpensivecontrolsystemThemaindrawbackofthefeedforwardcontrollerissensitivetounmodeldataandunconsideredexternaldisturbancessuchastemperaturedriftForanewtypeofpiezoelectricelectrohydraulicservovalvesystemthatneedshighcontrolprecisionmode1basedfeedforwardcontrollercannotobtaingoodcontroleffectThenacompoundcontrolmethodwithfeedforwardandfeedbackcontrolprojectwasproposedinthispape.Inthefeedbackcontrolloop，ahighprecisefuzzycontrolalgorithmwasadoptedThemethodcanobtaingoodperformance32HighprecisefuzzycontrolConventionalfuzzycontrollerhastwoinputvariables，eande，andoneoutputvariable（U），theyareerror,changeoferrorandoutputcontroloffuzzycontrollerInthenewtypeofpiezoelectricelectro-hydraulicservovalvesystem，thephysicalrangeoftheslidevalvepositionerror(andchangeoferror(e)are-x，xand-x，x，respectivelyThecorrespondingdiscreteuniversesofdiscourseofe，eanduareE，ECandUrespectivelyE,ECandUaredesignedasnormalizedform：