起重机中英文对照外文翻译文献Word文档格式.docx

起重机中英文对照外文翻译文献Word文档格式.docx

《起重机中英文对照外文翻译文献Word文档格式.docx》由会员分享，可在线阅读，更多相关《起重机中英文对照外文翻译文献Word文档格式.docx（21页珍藏版）》请在冰豆网上搜索。

Double-PendulumPayloadDynamics

Abstract：

Theusefulnessofcranesislimitedbecausethepayloadissupportedbyanoverheadsuspensioncablethatallowsoscilationtooccurduringcranemotion.Undercertainconditions,thepayloaddynamicsmayintroduceanadditionaloscillatorymodethatcreatesadoublependulum.Thispaperpresentsananalysisofthiseffectontowercranes.Thispaperalsoreviewsacommandgenerationtechniquetosuppresstheoscillatorydynamicswithrobustnesstofrequencychanges.Experimentalresultsarepresentedtoverifythattheproposedmethodcanimprovetheabilityofcraneoperatorstodriveadouble-pendulumtowercrane.Theperformanceimprovementsoccurredduringbothlocalandteleoperatedcontrol.

Keywords：

Crane,inputshaping,towercraneoscillation,vibration

I.INTRODUCTION

Thestudyofcranedynamicsandadvancedcontrolmethodshasreceivedsignificantattention.Cranescanroughlybedividedintothreecategoriesbasedupontheirprimarydynamicpropertiesandthecoordinatesystemthatmostnaturallydescribesthelocationofthesuspensioncableconnectionpoint.Thefirstcategory,bridgecranes,operateinCartesianspace,asshowninFig.1（a）.Thetrolleymovesalongabridge,whosemotionisperpendiculartothatofthetrolley.Bridgecranesthatcantravelonamobilebaseareoftencalledgantrycranes.Bridgecranesarecommoninfactories,warehouses,andshipyards.

Thesecondmajorcategoryofcranesisboomcranes,suchastheonesketchedinFig.1（b）.Boomcranesarebestdescribedinsphericalcoordinates,whereaboomrotatesaboutaxesbothperpendicularandparalleltotheground.InFig.1（b）,

istherotationaboutthevertical,Z-axis,and

istherotationaboutthehorizontal,Y-axis.Thepayloadissupportedfromasuspensioncableattheendoftheboom.Boomcranesareoftenplacedonamobilebasethatallowsthemtochangetheirworkspace.

Thethirdmajorcategoryofcranesistowercranes,liketheonesketchedinFig.1（c）.Thesearemostnaturallydescribedbycylindricalcoordinates.Ahorizontaljibarmrotatesaroundaverticaltower.Thepayloadissupportedbyacablefromthetrolley,whichmovesradiallyalongthejibarm.Towercranesarecommonlyusedintheconstructionofmultistorybuildingsandhavetheadvantageofhavingasmallfootprint-to-workspaceratio.Primarydisadvantagesoftowerandboomcranes,fromacontroldesignviewpoint,arethenonlineardynamicsduetotherotationalnatureofthecranes,inadditiontothelessintuitivenaturalcoordinatesystems.

Acommoncharacteristicamongallcranesisthatthepay-loadissupportedviaanoverheadsuspensioncable.Whilethisprovidesthehoistingfunctionalityofthecrane,italsopresentsseveralchallenges,theprimaryofwhichispayloadoscillation.Motionofthecranewilloftenleadtolargepayloadoscillations.Thesepayloadoscillationshavemanydetrimentaleffectsincludingdegradingpayloadpositioningaccuracy,increasingtaskcompletiontime,anddecreasingsafety.Alargeresearchefforthasbeendirectedatreducingoscillations.Anoverviewoftheseeffortsincranecontrol,concentratingmainlyonfeedbackmethods,isprovidedin[1].Someresearchershaveproposedsmoothcommandstoreduceexcitationofsystemflexiblemodes[2]–[5].Cranecontrolmethodsbasedoncommandshapingarereviewedin[6].

Manyresearchershavefocusedonfeedbackmethods,whichnecessitatetheadditionnecessitatetheadditionofsensorstothecraneandcanprovedifficulttouseinconjunctionwithhumanoperators.Forexample,somequaysidecraneshavebeenequippedwithsophisticatedfeedbackcontrolsystemstodampenpayloadsway.However,themotionsinducedbythecomputercontrolannoyedsomeofthehumanoperators.Asaresult,thehumanoperatorsdisabledthefeedbackcontrollers.Giventhatthevastmajorityofcranesaredrivenbyhumanoperatorsandwillneverbeequippedwithcomputer-basedfeedback,feedbackmethodsarenotconsideredinthispaper.

Inputshaping[7],[8]isonecontrolmethodthatdramaticallyreducespayloadoscillationbyintelligentlyshapingthecommandsgeneratedbyhumanoperators[9],[10].Usingroughestimatesofsystemnaturalfrequenciesanddampingratios,aseriesofimpulses,calledtheinputshaper,isdesigned.Theconvolutionoftheinputshaperandtheoriginalcommandisthenusedtodrivethesystem.Thisprocessisdemonstratedwithatwo-impulseinputshaperandastepcommandinFig.2.Notethattherisetimeofthecommandisincreasedbythedurationoftheinputshaper.Thissmallincreaseintherisetimeisnormallyontheorderof0.5–1periodsofthedominantvibrationmode.

Fig.1.Sketchesof（a）bridgecrane,（b）boomcrane,（c）andtowercrane.

Fig.2.Input-shapingprocess.

Inputshapinghasbeensuccessfullyimplementedonmanyvibratorysystemsincludingbridge[11]–[13],tower[14]–[16],andboom[17],[18]cranes,coordinatemeasurementmachines[19]–[21],roboticarms[8],[22],[23],deminingrobots[24],andmicro-millingmachines[25].

Mostinput-shapingtechniquesarebaseduponlinearsystemtheory.However,someresearcheffortshaveexaminedtheextensionofinputshapingtononlinearsystems[26],[14].Inputshapersthatareeffectivedespitesystemnonlinearitieshavebeendeveloped.Theseincludeinputshapersfornonlinearactuatordynamics,friction,anddynamicnonlinearities[14],[27]–[31].Onemethodofdealingwithnonlinearitiesistheuseofadaptiveorlearninginputshapers[32]–[34].Despitetheseefforts,thesimplestandmostcommonwaytoaddresssystemnonlinearitiesistoutilizearobustinputshaper[35].Aninputshaperthatismorerobusttochangesinsystemparameterswillgenerallybemorerobusttosystemnonlinearitiesthatmanifestthemselvesaschangesinthelinearizedfrequencies.Inadditiontodesigningrobustshapers,inputshaperscanalsobedesignedtosuppressmultiplemodesofvibration[36]–[38].

InSectionII,themobiletowercraneusedduringexperimentaltestsforthispaperispresented.InSectionIII,planarand3-Dmodelsofatowercraneareexaminedtohighlightimportantdynamiceffects.SectionIVpresentsamethodtodesignmultimodeinputshaperswithspecifiedlevelsofrobustness.InSectionV,thesemethodsareimplementedonatowercranewithdouble-pendulumpayloaddynamics.Finally,inSectionVI,theeffectoftherobustshapersonhumanoperatorperformanceispresentedforbothlocalandteleoperatedcontrol.

II.MOBILETOWERCRANE

Themobiletowercrane,showninFig.3,hasteleoperationcapabilitiesthatallowittobeoperatedinreal-timefromanywhereintheworldviatheInternet[15].Thetowerportionofthecrane,showninFig.3（a）,isapproximately2mtallwitha1mjibarm.ItisactuatedbySiemenssynchronous,ACservomotors.Thejibiscapableof340°

rotationaboutthetower.Thetrolleymovesradiallyalongthejibviaaleadscrew,andahoistingmotorcontrolsthesuspensioncablelength.MotorencodersareusedforPDfeedbackcontroloftrolleymotionintheslewingandradialdirections.ASiemensdigitalcameraismountedtothetrolleyandrecordstheswingdeflectionofthehookatasamplingrateof50Hz[15].

Themeasurementresolutionofthecameradependsonthesuspensioncablelength.Forthecablelengthsusedinthisresearch,theresolutionisapproximately0.08°

.Thisisequivalenttoa1.4mmhookdisplacementatacablelengthof1m.Inthiswork,thecameraisnotusedforfeedbackcontrolofthepayloadoscillation.Theexperimentalresultspresentedinthispaperutilizeencoderdatatodescribejibandtrolleypositionandcameradatatomeasurethedeflectionanglesofthehook.

BasemobilityisprovidedbyDCmotorswithomnidirectionalwheelsattachedtoeachsupportleg,asshowninFig.3（b）.ThebaseisunderPDcontrolusingtwoHiBotSH2-basedmicrocontrollers,withfeedbackfrommotor-shaft-mountedencoders.Themobilebasewaskeptstationaryduringallexperimentspresentedinthispaper.Therefore,themobiletowercraneoperatedasastandardtowercrane.

TableIsummarizestheperformancecharacteristicsofthetowercrane.Itshouldbenotedthatmostoftheselimitsareenforcedviasoftwareandarenotthephysicallimitationsofthesystem.Theselimitationsareenforcedtomorecloselymatchtheoperationalparametersoffull-sizedtowercranes.

Fig.3.Mobile,portabletowercrane,（a）mobiletowercrane,（b）mobilecranebase.

TABLEIMOBILETOWERCRANEPERFORMANCELIMITS

Fig.4Sketchoftowercranewithadouble-pendulumdynamics.

III.TOWERCRANEMODEL

Fig.4showsasketchofatowercranewithadouble-pendulumpayloadconfiguration.Thejibrotatesbyanangle

aroundtheverticalaxisZparalleltothetowercolumn.Thetrolleymovesradiallyalongthejib;

itspositionalongthejibisdescribedby

.Thesuspensioncablelengthfromthetrolleytothehookisrepresentedbyaninflexible,masslesscableofvariablelength

.Thepayloadisconnectedtothehookviaaninflexible,masslesscableoflength

.Boththehookandthepayloadarerepresentedaspointmasseshavingmasses

and

respectively.

TheanglesdescribingthepositionofthehookareshowninFig.5（a）.Theangle

representsadeflectionintheradialdirection,alongthejib.Theangle

representsatangentialdeflection,perpendiculartothejib.InFig.5（a）,

isintheplaneofthepage,and

liesinaplaneoutofthepage.TheanglesdescribingthepayloadpositionareshowninFig.5（b）.Noticethattheseanglesaredefinedrelativetoalinefromthetrolleytothehook.Ifthereisnodeflectionofthehook,thent