机械手相关的外文文献.docx
- 文档编号:28781188
- 上传时间:2023-07-19
- 格式:DOCX
- 页数:13
- 大小:26.42KB
机械手相关的外文文献.docx
《机械手相关的外文文献.docx》由会员分享,可在线阅读,更多相关《机械手相关的外文文献.docx(13页珍藏版)》请在冰豆网上搜索。
机械手相关的外文文献
附件一:
ARapidlyDeployableManipulatorSystem
Author:
ChristiaanJ。
J。
Paredis,H.BenjaminBrown,PradeepK.Khosla
Abstract:
Arapidlydeployablemanipulatorsystemcombinestheflexibilityofreconfigurablemodularhardwarewithmodularprogrammingtools,allowingtheusertorapidlycreateamanipulatorwhichiscustom-tailoredforagiventask.Thisarticledescribestwomainaspectsofsuchasystem,namely,theReconfigurableModularManipulatorSystem(RMMS)hardwareandthecorrespondingcontrolsoftware。
1Introduction
Robotmanipulatorscanbeeasilyreprogrammedtoperformdifferenttasks,yettherangeoftasksthatcanbeperformedbyamanipulatorislimitedbymechanicalstructure。
Forexample,amanipulatorwell—suitedforprecisemovementacrossthetopofatablewouldprobablynobecapableofliftingheavyobjectsintheverticaldirection.Therefore,toperformagiventask,oneneedstochooseamanipulatorwithanappropriatemechanicalstructure。
Weproposetheconceptofarapidlydeployablemanipulatorsystemtoaddresstheabovementionedshortcomingsoffixedconfigurationmanipulators.AsisillustratedinFigure1,arapidlydeployablemanipulatorsystemconsistsofsoftwareandhardwarethatallowtheusertorapidlybuildandprogramamanipulatorwhichiscustomtailoredforagiventask.
ThecentralbuildingblockofarapidlydeployablesystemisaReconfigurableModularManipulatorSystem(RMMS)。
TheRMMSutilizesastockofinterchangeablelinkandjointmodulesofvarioussizesandperformancespecifications.OnesuchmoduleisshowninFigure2。
Bycombiningthesegeneralpurposemodules,awiderangeofspecialpurposemanipulatorscanbeassembled。
Recently,therehasbeenconsiderableinterestintheideaofmodularmanipulators,forresearchapplicationsaswellasforindustrialapplications。
However,mostofthesesystemslackthepropertyofreconfigurability,whichiskeytotheconceptofrapidlydeployablesystems.TheRMMSisparticularlyeasytoreconfigurethankstoitsintegratedquick-couplingconnectorsdescribedinSection3。
EffectiveuseoftheRMMSrequires,TaskBasedDesignsoftware。
Thissoftwaretakesasinputdescriptionsofthetaskandoftheavailablemanipulatormodules;itgeneratesasoutputamodularassemblyconfigurationoptimallysuitedtoperformthegiventask。
Severaldifferentapproacheshavebeenusedsuccessfullytosolvesimpli—fiedinstancesofthis
Athirdimportantbuildingblockofarapidlydeployablemanipulatorsystemisaframeworkforthegenerationofcontrolsoftware。
Toreducethecomplexityofsoftwaregenerationforreal—timesensor-basedcontrolsystems,asoftwareparadigmcalledsoftwareassemblyhasbeenproposedintheAdvancedManipulatorsLaboratoryatCMU.Thisparadigmcombinestheconceptofreusableandreconfigurablesoftwarecomponents,asissupportedbytheChimerareal-timeoperatingsystem,withagraphicaluserinterfaceandavisualprogramminglanguage,inplementedinOnika.
Althoughthesoftwareassemblyparadigmprovidesthesoftwareinfrastructureforrapidlyprogrammingmanipulatorsystems,itdoesnotsolvetheprogrammingproblemitself.Explicitprogrammingofsensor—basedmanipulatorsystemsiscumbersomeduetotheextensiveamountofdetailwhichmustbespecifiedfortherobottoperformthetask。
Thesoftwaresynthesisproblemforsensor-basedrobotscanbesimplifieddramatically,byprovidingrobustroboticskills,thatis,encapsulatedstrategiesforaccomplishingcommontasksintherobotstaskdomain。
Suchroboticskillscanthenbeusedatthetasklevelplanningstagewithouthavingtoconsideranyofthelow—leveldetails
Asanexampleoftheuseofarapidlydeployablesystem,consideramanipulatorinanuclearenvironmentwhereitmustinspectmaterialandspaceforradioactivecontamination,orassembleandrepairequipment。
Insuchanenvironment,widelyvariedkinematic(e.g。
workspace)anddynamic(e。
g。
speed,payload)performanceisrequired,andtheserequirementsmaynotbeknownapriori。
Insteadofpreparingalargesetofdifferentmanipulatorstoaccomplishthesetasks—anexpensivesolution—onecanusearapidlydeployablemanipulatorsystem.Considerthefollowingscenario:
assoonasaspecifictaskisidentified,thetaskbaseddesignsoftwaredeterminesthetask.ThisoptimalconfigurationisthenassembledfromtheRMMSmodulesbyahumanor,inmanipulator。
Theresultingmanipulatorisrapidlyprogrammedbyusingthesoftwareassemblyparadigmandourlibraryofroboticskills.Finally,themanipulatorisdeployedtoperformitstask。
Althoughsuchascenarioisstillfuturistic,thedevelopmentofthereconfigurablemodularmanipulatorsystem,describedinthispaper,isamajorstepforwardtowardsourgoalofarapidlydeployablemanipulatorsystem。
Ourapproachcouldformthebasisforthenextgenerationofautonomousmanipulators,inwhichthetraditionalnotionofsensor—basedautonomyisextendedtoconfiguration—basedautonomy。
Indeed,althoughadeployedsystemcanhaveallthesensoryandplanninginformationitneeds,itmaystillnotbeabletoaccomplishitstaskbecausethetaskisbeyondthesystem'sphysicalcapabilities.Arapidlydeployablesystem,ontheotherhand,couldadaptitsphysicalcapabilitiesbasedontaskspecificationsand,withadvancedsensing,control,andplanningstrategies,accomplishthetaskautonomously。
2Designofself-containedhardwaremodules
Inmostindustrialmanipulators,thecontrollerisaseparateunithousingthesensorinterfaces,poweramplifiers,andcontrolprocessorsforallthejointsofthemanipulator.Alargenumberofwiresisnecessarytoconnectthiscontrolunitwiththesensors,actuatorsandbrakeslocatedineachofthejointsofthemanipulator。
Thelargenumberofelectricalconnectionsandthenon-extensiblenatureofsuchasystemlayoutmakeitinfeasibleformodularmanipulators.Thesolutionweproposeistodistributethecontrolhardwaretoeachindividualmoduleofthemanipulator。
Thesemodulesthenbecomeself-containedunitswhichincludesensors,anactuator,abrake,atransmission,asensorinterface,amotoramplifier,andacommunicationinterface,asisillustratedinFigure3。
Asaresult,onlysixwiresarerequiredforpowerdistributionanddatacommunication。
2.1Mechanicaldesign
ThegoaloftheRMMSprojectistohaveawidevarietyofhardwaremodulesavailable.Sofar,wehavebuiltfourkindsofmodules:
themanipulatorbase,alinkmodule,threepivotjointmodules(oneofwhichisshowninFigure2),andonerotatejointmodule.Thebasemoduleandthelinkmodulehavenodegrees—of-freedom;thejointmoduleshavedegree—of-freedomeach.ThemechanicaldesignofthejointmodulescompactlyfitsaDC—motor,afail-safebrake,atachometer,aharmonicdriveandaresolver
Thepivotandrotatejointmodulesusedifferentoutsidehousingstoprovidetheright—angleorin—lineconfigurationrespectively,butareidenticalinternally。
Figure4showsincross-sectiontheinternalstructureofapivotjoint.EachjointmoduleincludesaDCtorquemotorand100:
1harmonic-drivespeedreducer,andisratedatamaximumspeedof1。
5rad/sandmaximumtorqueof270Nm.Eachmodulehasamassofapproximately10.7kg.Asingle,compact,X-typebearingconnectsthetwojointhalvesandprovidestheneededoverturningrigidity。
Ahollowmotorshaftpassesthroughalltherotarycomponents,andprovidesachannelforpassageofcablingwithminimalflexing.
2。
2Electronicdesign
Thecustom-designedon-boardelectronicsarealsodesignedaccordingtotheprincipleofmodularity。
EachRMMSmodulecontainsamotherboardwhichprovidesthebasicfunctionalityandontowhichdaughtercardscanbestackedtoaddmodulespecificfunctionality。
ThemotherboardconsistsofaSiemens80C166microcontroller,64KofROM,64KofRAM,anSMCCOM20020universallocalareanetworkcontrollerwithanRS-485driver,andanRS—232driver。
ThefunctionofthemotherboardistoestablishcommunicationwiththehostinterfaceviaanRS—485busandtoperformthelowlevelcontrolofthemodule,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,morethanonesuchdaughtercardcanbestackedonto由es创nemotherboard.
3Integratedquick-couplingconnectors
Tomakeamodularmanipulatorbereconfigurable,itisnecessarythatthemodulescanbeeasilyconnectedwitheachother.Wehavedevelopedaquick—couplingmechanismwithwhichasecuremechanicalconnectionbetweenmodulescanbeachievedbysimplyturningaringhandtight;notoolsarerequired。
AsshowninFigure5,keyedflangesprovidepreciseregistrationofthetwomodules。
Turningofthelockingcollaronthemaleendproducestwodistinctmotions:
firstthefingersofthelockingringrotate(withthecollar)about22。
5degreesandcapturethefingersontheflanges;second,thecollarrotatesrelativetothelockingring,whileacammechanismforcesthefingersinwardtosecurelygripthematingflanges.Aball—transfermechanismbetweenthecollarandlockingringautomaticallyproducesthissequenceofmotions。
Atthesametimethemechanicalconnectionismade,pneumaticandelectronicconnectionsarealsoestablished.Insidethelockingringisamodularconnectorthathas30male
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 机械手 相关 外文 文献