机械手类毕业设计外文文献翻译.docx

毕业设计(论文)外文资料翻译系别：专业：班级：姓名：学号：外文出处：附件：L原文；2.译文2013年03月附件一：ARapidlyDeployableManipulatorSystemChristiaanJJ.Paredis,H.BenjaminBrown,PradeepK.KhoslaAbstract:Arapidlydeployablemanipulatorsystemcombinestheflexibilityofreconfigurablemodularhardwarewithmodularprogrammingtools,allowingtheusertorapidlycreateamanipulatorwhichiscustom-tailoredforagiventask.Thisarticledescribestwomainaspectsofsuchasystem,namely,theReconfigurableModularManipulatorSystem(RMMS)hardwareandthecorrespondingcontrolsoftware.1 IntroductionRobotmanipulatorscanbeeasilyreprogrammedtoperformdifferenttasks,yettherangeoftasksthatcanbeperformedbyamanipulatorislimitedbymechanicalstructure.Forexample,amanipulatorwell-suitedforprecisemovementacrossthetopofatablewouldprobablynobecapableofliftingheavyobjectsintheverticaldirection.Therefore,toperformagiventask,oneneedstochooseamanipulatorwithanappropriatemechanicalstructure.Weproposetheconceptofarapidlydeployablemanipulatorsystemtoaddresstheabovementionedshortcomingsoffixedconfigurationmanipulators.AsisillustratedinFigure1,arapidlydeployablemanipulatorsystemconsistsofsoftwareandhardwarethatallowtheusertorapidlybuildandprogramamanipulatorwhichisCustomtailoredforagiventask.ThecentralbuildingblockofarapidlydeployablesystemisaReconfigurableModularManipulatorSystem(RMMS).TheRMMSutilizesastockofinterchangeablelinkandjointmodulesofvarioussizesandperformancespecifications.OnesuchmoduleisshowninFigure2.Bycombiningthesegeneralpurposemodules,awiderangeofspecialpurposemanipulatorscanbeassembled.Recently,therehasbeenconsiderableinterestintheideaofmodularmanipulators2,4,5,7,9,10,14,forresearchapplicationsaswellasforindustrialapplications.However,mostofthesesystemslackthepropertyofreconfigurability,whichiskeytotheconceptofrapidlydeployablesystems.TheRMMSisparticularlyeasytoreconfigurethankstoitsintegratedquick-couplingconnectorsdescribedinSection3.EffectiveuseoftheRMMSrequires,TaskBasedDesignsoftware.Thissoftwaretakesasinputdescriptionsofthetaskandoftheavailablemanipulatormodules;itgeneratesasoutputamodularassemblyconfigurationOptimallysuitedtoperformthegiventask.Several(Iifferentapproacheshavebeenusedsuccessfullytosolvesimpli-fiedinstancesofthiscomplicatedproblem.Athirdimportantbuildingblockofarapidlydeployablemanipulatorsystemisaframeworkforthegenerationofcontrolsoftware.Toreducethecomplexityofsoftwaregenerationforreal-timesensor-basedcontrolsystems,asoftwareparadigmcalledsoftwareassemblyhasbeenproposedintheAdvancedManipulatorsLaboratoryatCMU.Thisparadigmcombinestheconceptofreusableandreconfigurablesoftwarecomponents,asissupportedbyIheChimerareal-timeoperatingsystem15,withagraphicaluserinterfaceandavisualprogramminglanguage,implementedinOnikaAlthoughthesoftwareassemblyparadigmprovidesthesoftwareinfrastructureforrapidlyprogrammingmanipulatorsystems,itdoesnotsolvetheprogrammingproblemitself.Explicitprogrammingofsensor-basedmanipulatorsystemsiscumbersomeduetotheextensiveamountOfdetailwhichmustbespecifiedfortherobottoperformthetask.Thesoftwaresynthesisproblemforsensor-basedrobotscanbesimplifieddramatically,byprovidingrobustroboticskills,thatis,encapsulatedstrategiesforaccomplishingcommontasksintherobotstaskdomain1l.SuchroboticskillscanthenbeusedatthetasklevelplanningstagewithouthavingtoconsideranyoftheIow-IeveldetailsAsanexampleoftheuseofarapidlydeployablesystem,consideramanipulatorinanuclearenvironmentwhereitmustinspectmaterialandspaceforradioactivecontamination,orassembleandrepairequipment.Insuchanenvironment,widelyvariedkinematic(e.g.,workspace)anddynamic(e.g.,speed,payload)performanceisrequired,andtheserequirementsmaynotbeknownapriori.Insteadofpreparingalargesetofdifferentmanipulatorstoaccomplishthesetasks一anexpensivesolution-onecanusearapidlydeployablemanipulatorsystem.Considerthefollowingscenario:assoonasaspecifictaskisidentified,thetaskbaseddesignsoftwaredeterminesthetask.ThisoptimalconfigurationisthenassembledfromtheRMMSmodulesbyahumanor,inthefuture,possiblybyanothermanipulator.TheFesultingmanipulatorisrapidlyprogrammedbyusingthesoftwareassemblyparadigmandourlibraryofroboticskills.Finally,themanipulatorisdeployedtoperformitstask.Althoughsuchascenarioisstillfuturistic,thedevelopmentofthereconfigurablemodularmanipulatorsystem,describedinthispaper,isamajorstepforwardtowardsourgoalofarapidlydeployablemanipulatorsystem.Ourapproachcouldformthebasisforthenextgenerationofautonomousmanipulators,inwhichthetraditionalnotionofsensor-basedautonomyisextendedtoconfiguration-basedautonomy.Indeed,althoughadeployedsystemcanhaveallthesensoryandplanninginfbrmationitneeds,itmaystillnotbeabletoaccomplishitstaskbecausethetaskisbeyondthesystem,sphysicalcapabilities.Arapidlydeployablesystem,ontheOtherhand,couldadaptitsphysicalcapabilitiesbasedontaskspecificationsand,withadvancedsensing,control,andplanningstrategies,accomplishthetaskautonomously.2 Designofself-containedhardwaremodulesInmostindustrialmanipulators,thecontrollerisaseparateunithousingthesensorinterfaces,poweramplifiers,andcontrolprocessorsforallthejointsofthemanipulator.Alargenumberofwiresisnecessarytoconnectthiscontrolunitwiththesensors,actuatorsandbrakesIocatedineachofthejointsofthemanipulator.Thelargenumberofelectricalconnectionsandthenon-extensiblenatureofsuchasystemlayoutmakeitinfeasibleformodularmanipulators.ThesolutionweproposeistodistributeIhecontrolhardwaretoeachindividualmoduleofthemanipulator.Thesemodulesthenbecomeself-containedunitswhichincludesensors,anactuator,abrake,atransmissionsensorinterface,amotoramplifier,andacommunicationinterface,asisillustratedinFigure3.Asaresult,onlysixwiresarerequiredforpowerdistributionanddatacommunication.2.1 MechanicaldesignThegoaloftheRMMSprojectistohaveawidevarietyofhardwaremodulesavailable.Sofar,wehavebuiltfburkindsofmodules:themanipulatorbase,alinkmodule,threepivotjointmodules(oneofwhichisshowninFigure2),andonerotatejointmodule.Thebasemoduleandthelinkmodulehavenodegrees-of-freedom;thejointmoduleshaveonedegree-of-freedomeach.ThemechanicaldesignofthejointmodulescompactlyfitsaDC-motor,afail-safebrake,atachometer,aharmonicdriveandaresolver.Thepivotandrotatejointmodulesusedifferentoutsidehousingstoprovidetheright-angleorin-lineConfigurationrespectively,butareidenticalinternally.Figure4showsincross-sectiontheinternalstructureofapivotjoint.EachjointmoduleincludesaDCtorquemotorand100:1harmonic-drivespeedreducer,andisratedatamaximumspeedof1.5radsandmaximumtorqueof270Nm.Eachmodulehasamassofapproximately10.7kg.Asingle,compact,X-typebearingconnectsthetwojointhalvesandprovidestheneededoverturningrigidity.Ahollowmotorshaftpassesthroughalltherotarycomponents,andprovidesachannelforpassageofCablingwithminimalflexing.2.2 ElectronicdesignThecustom-designedon-boardelectronicsarealsodesignedaccordingtotheprincipleofmodularity.EachRMMSmodulecontainsamotherboardwhichprovidesthebasicfunctionalityandontowhichdaughtercardscanbestackedtoaddmodulespecificfunctionality.ThemotherboardconsistsofaSiemens80C166microcontroller,64KofROM,64KofRAM,anSMCCOM20020universallocalareanetworkcontrollerwithanRS-485driver,andanRS-232driver.ThefunctionofthemotherboardistoestablishcommunicationwiththehostinterfaceviaanRS-485busandtoperformtheIowlevelcontrolofthemodule,asisexplainedinmoredetailinSection4.TheRS-232serialbusdriverallowsforsimplediagnosticsandsoftwareprototyping.Astackingconnectorpermitstheadditionofanindefinitenumberofdaughtercardswithvariousfunctions,suchassensorinterfaces,motorcontrollers,RAMexpansionetc.Inourcurrentimplementation,onlymoduleswithactuatorsincludeadaughtercard.Thiscardcontainsa16bitresolvertodigitalconverter,a12bitA/DConvertertointerfacewiththetachometer,anda12bitD/AConvertertocontrolthemotoramplifier;wehaveusedanofthe-shelfmotoramplifier(GalilMotionControlmodelSSA-8/80)todrivetheDC-motor.Formoduleswithmorethanonedegree-of-freedom,forinstanceawristmodule,morethanonesuchdaughtercardcanbeStackedontothesamemotherboard.3 Integratedquick-couplingconnectorsTomakeamodularmanipulatorbereconfigurable,itisnecessarythatthemodulescanbeeasilyconnectedwitheachother.Wehavedevelopedaquick-couplingmechanismwithwhichasecuremechanicalconnectionbetweenmodulescanbeachievedbysimplyturningaringhandtighl;notoolsarerequired.AsshowninFigure5,keyedflangesprovidepreciseregistrationofthetwomodules.Turningofthelockingcollaronthemaleendproducestwodistinctmotions:firstthefingersofthelockingringrotate(withthecollar)about22.5degreesandcapturethefingersontheflanges;second,thecollarrotatesrelativetothelockingring,whileacammechanismforcesthefingersinwardtosecurelygripthematingflanges.Aball-transfermechanismbetweenthecollarandlockingringautomaticallyproducesthissequenceofmotions.Atthesametimethemechanicalconnectionismade,pneumaticandelectronicconnectionsarealsoestablished.Insidethelockingringisamodularconnectorthathas30maleelectricalpinsplusapneumaticcouplerinthemiddle.Thesecorrespondtomatchingfemalecomponentsonthematingconnector.Setsofpinsarewiredinparalleltocarrythe72V-25Apowerformotorsandbrakes,and48V-6Apowerfortheelectronics.AdditionalpinscarrysignalsfortwoRS-485serialcommunicationbussesandfourvideobusses.Aplasticguidecollarplussixalignmentpinspreventdamagetotheconnectorpinsandassureproperalignment.TheplasticblockholdingIhefemalepinscanrotateinthehousingtoaccommodatetheeightdifferentpossibleconnectionorientations(845degrees).TherelativeorientationisautomaticallyregiSteredbymeansofaninfraredLEDinthefemaleconnectorandeightphotodetectorsinthemaleconnector.4 ARMbuscommunicationsystemEachofthemodulesoftheRMMScommunicateswithaVME-basedhostinterfaceoveralocalareanetworkcalledtheARMbus;eachmoduleisanodeofthenetwork.ThecommunicationisdoneinaserialfashionoveranRS-485buswhichrunsthroughthelengthofthemanipulator.WeusetheARCNETprotocol1implementedonadedicatedIC(SMCCOM20020).ARCNETisadeterministictoken-passingnetworkschemewhichHvoidsnetworkcollisionsandguaranteeseachnodeitstimetoaccessthenetwork.Blocksofinformationcalledpacketsmaybesentfromanynodeonthenetworktoanyoneoftheothernodes,ortoallnodessimultaneously(broadcast).Eachnodemaysendonepacketeachtimeitgetsthetoken.Themaximumnetworkthroughputis5Mbs.Thefirstnodeofthenetworkresidesonthehostinterfacecard,asisdepictedinFigure6.InadditiontoaVMEaddressdecoder,thiscardcontainsessentiallythesamehardwareonecanfindonamodulemotherboard.ThecommunicationbetweentheVMEsideofthecardandtheARCNETsideoccursthroughdual-portRAM.Therearetwokindsofdatapassedoverthelocalareanetwork.Duringthemanipulatorinitializationphase,themodulesconnecttothenetworkonebyone,startingatthebaseandendingattheend-effector.Onjoiningthenetwork,eachmodulesendsadata-packettothehostinterfacecontainingitsserialnumberanditsrelativeorientationwithrespecttothepreviousmodule.Thisinfrmationallowsustoautomaticallydeterminethecurrentmanipulatorconfiguration.Duringtheoperationphase,thehostinterfaceCommunicateswitheachofthenodesat400Hz.Thedatathatisexchangeddependsonthecontrolmode-centralizedOrdistributed.Incentralizedcontrolmode,thetorquesfbrallthejointsarecomputedontheVME-basedreal-timeprocessingunit(RTPU),assembledintoadata-packetbythemicrocontrolleronthehostinterfacecardandbroadcastovertheARMbustoallthenodesofthenetwork.Eachnodeextractsitstorquevaluefromthepacketandrepliesbysendingadata-packetcontainingtheresolverandtachometerreadings.Indistributedcontrolmode,ontheotherhand,thehostcomputerbroadcaststhedesiredjointvaluesandfeed-forwardtorques.Locally,ineachmodule,thecontrolloopcanthenbeclosedataFrequencymuchhigherthan400Hz.ThemodulesstillsendsensorreadingsbacktothehostinterfacetobeusedintheComputationofthesubsequentfeed-forwardtorque.5 ModularandreconfigurablecontrolsoftwareThecontrolsoftwarefortheRMMShasbeendevelopedusingtheChimerareal-timeoperatingsystem,Whichsupportsreconfigurableandreusablesoftwarecomponents15.ThesoftwarecomponentsusedtocontroltheRMMSarelistedinTable1.Thetrjjline,dis,andgrav_compcomponentsrequiretheknowledgeofcertainconfigurationdependentparametersoftheRMMS,suchasthenumberofdegrees-of-freedom,theDenavit-Hartenbergparametersetc.Duringtheinitializationphase,theRMMSinterfaceestablishescontactwitheachofthehardwaremodulestodetermineautomaticallywhichmodulesarebeingusedandinwhichorderandOrientationtheyhavebeenassembled.Foreachmodule,adatafilewithaparametricmodelisread.Bycombiningthisinformationfbrallthemodules,kinematicanddynamicmodelsoftheentiremanipulatorarebuilt.Aftertheinitialization,thermmssoftwareComponentoperatesinadistributedcontrolmodeinwhichthemicrocontrollersofeachoftheRMMSmodulesperformPlDcontrollocallyat1900Hz.Thecommunicationbetweenthemodulesandthehostinterfaceisat400Hz,whichcandifferfromthecyclefrequencyofthermmssoftwarecomponent.Sinceweuseatriplebuffermechanism16forthecommunicationthroughthedual-portRAMontheARMbushostinterface,nosynchronizationorhandshakingisnecessary.BecauseclosedforminversekinematicsdonotexistforallpossibleRMMSconfigurations,weuseadampedleast-squareskinematiccontrollertodotheinversekinematicscomputationnumerically.6 SeamlessintegrationofsimulationToassisttheuserinevaluatingwhetheranRMMScon-figurationcansuccessfullycompleteagiventask,wehavebuiltasimulator.ThesimulatorisbasedontheTeleGriprobotsimulationsoftwarefromDenebInc.,andrunsonanSGICrimsonwhichisconnectedwiththereal-timeprocessingunitthroughaBit3VME-to-VMEadaptor,asisshowninFigure6.AgraphicaluserinterfaceallowstheusertoassemblesimulatedRMMSConfigurationsverymuchlikeassemblingtherealhardware.CompletedconfigurationscanbetestedandprogrammedusingtheTeleGripfunctionsforrobotdevices.TheconfigurationscanalsobeinterfacedwiththeChimerareal-timesoftwarerunningonthesameRTPUsusedtocontroltheactualhardware.Asaresult,itispossibletoevaluatenotonlythemovementsofthemanipulatorbutalsotherealtimeCPUusageandloadbalancing.Figure7showsanRMMSsimulationcomparedwiththeactualtaskexecution.7 SummaryWehavedevelopedaReconfigurableModularManipulatorSystemwhichcurrentlyconsistsofsixhardwaremodules,withatotaloffourdegrees-of-freedom.ThesemodulescanbeassembledinalargenumberofClifferentconfigurationstotailorthekinematicanddynamicpropertiesofthemanipulatortothetaskathand.ThecontrolsoftwarefortheRMMSautomaticallyadaptstotheassemblyconfigurationbybuildingkinematicanddynamicmodelsofthemanipulator;thisistotallytransparenttotheuser.Toassisttheuserinevaluatingwhetheramanipulatorconfigurationiswellsuitedforagiventask,wehavealsobuiltasimulator.AcknowledgmentThisresearchwasfundedinpartbyDOEundergrantDE-F902-89ER14042,bySandiaNationalLaboratoriesundercontractAL-3020,bytheDepartmentofElectricalandComputerEngineering,andbyTheRoboticsInstitute,CarnegieMellonUniversity.TheauthorswouldalsoliketothankRandyCasciola,MarkDeLouis,EricHoffman,andJimMoodyforIheirvaluablecontributionstothedesignoftheRMMSsystem.附件二：可迅速布置的机械手系统ChristiaanJ.J.Paredis,H.BenjaminBrown,PradeepK.Khosla摘要:一个迅速可部署的机械手系统，可以使再组合的标准化的硬件的灵活性用标准化的编程工具结合，允许用户迅速建立为一项规定的任务来通常地控制机械手。这篇文章描述这样的一个系统的两个主要方面，即，再组合的标准化的机械手系统(RMMS)硬件和相应控制软件。1介绍机器人操纵装置可能容易被程序重调执行不同的任务，然而一个机械手可以执行的任务的范围已经被它的机械结构限制。例如，一个很适合准确的运动的机械手在一张桌子上部或许将不能朝着垂直的方向举起重物。因此，执行规定的任务，需要有一个适宜的机械结构来选择机械手。