关于机械手的英文文献

IndustrialRobotsforManipulationwithParallelKinematicMachinesZdeněkKolíbalBrnoUniversityofTechnology,FacultyofMechanicalEngineering,Technicka2,61669Brno,CzechRepublic,e-mail:[e-mail]:Thepresentedarticleanalysesstructuresofkinematicchainsinindustrialrobots,i.e.theirpositioningandorientationmechanismswithrespecttopositioningofend-effectorswithintheworkspaceofparallelkinematicmachineandinitsvicinitywiththeaimtofacilitateaselectionofappropriateindustrialrobotforautomaticin–betweenoperationalmanipulationintheperipheryofsuchamachineorproductionsystems.Keywords:Industrialrobot,kinematicchain,linkage,arrangement,machiningcentre,parallelkinematicIINTRODUCTIONWithdevelopmentofcontrolsystemsandcomputertechnology,theconstructionofproductionmachines,andmachiningcentresinparticular,haswitnessedarevivaloftheso–calledStewardplatformpositionedinspaceasaplanesuspendedevenlyinthreeorsixpointsbymeansoflinearactuators.Thesameprincipleformsthebasisoftheindustrialrobotwiththisparallelkinematicsofitsbasickinematicchain-TRICEPTHP1.writtenintwocolumns.Oneoftheadvantagesofsodesignedmachiningcentresisarelativeeaseofbuildingthemintotherunningworkunits.Heretheuseofindustrialrobotsseemstobeanappropriateformofin–betweenoperationalmanipulations.However,theselectionofrobotscannotbecasual;therehastobeanall–sidedadaptationoftherobottotheconstructionandhandlingpossibilitiesofparallelkinematicmachines,i.e.adaptationintermsofmorphology(architectureofkinematicchain,numberofdegreesoffreedom),intermsofpurpose(selectionofappropriateendeffectors,ifpossibleautomaticallyreplaceable)andintermsofcontrol[3].If,however,themachiningcentreisnotequippedwithanothermanipulationperipheraldevice,ascanbeseene.g.inFig.1,theindustrialrobothastodirectlyencompasstheworkspaceoftheservicedmachiningcentreandaflowofmaterial(semi-productsandwork–pieces)isaccomplisheddirectlybythisindustrialrobot.Figure1aMachiningcentreofcompanyINGERSOLLFigure1bMachiningcentreofcompanyKearney&TreckerInthecaseofperipheryfromFig.1,itisevidentthatapertinentindustrialrobottobeusedforfurthermanipulationisnotsignificantlylimitedintermsofmainlyitsmorphologyselection(kinematicstructure);thereforethesecasesarenotasubjectofthepresentwork.Acompletelydifferentisthecasewhenadirectroboticmanipulationisrequiredforthemachiningcentrewithparallelkinematic,whichisdesignedintermsofcurrenttrends,i.e.thecomponentsandmechanismsofthecentrevirtuallyencompassitsworkspace(seeFig.2).Figure2aMachiningcentreofFhIChemnitzCurrentmachiningcentreswithparallelkinematics(seeFig.2)can,intermsofindustrialrobotdirectserviceability,rankamongproductionmachineswithspace–limitedserviceability;thereforethisshouldbetakenintoaccountfortheselectionofindustrialrobots.Figure2bMachiningcentreofcompanyGIDDING&LEWISFigure2cMachiningcentreofcompanyINGERSOLLIIBASICANDDERIVEDTYPESOFINDUSTRIALROBOTSAsstatedinmostoftheexistingpublications,basictypesofindustrialrobotscanbethosedescribedinFig.3:Figure3aCartesiantype(K)withlinkageofkinematicpairsTTTFigure3bCylindricaltype(C)withlinkageofkinematicpairsRTTFigure3cSphericaltype(S)withlinkageofkinematicpairsRRTFigure3dAnthropomorphous(angular,torus)type(A)withlinkageofkinematicpairsRRRFurtherpracticaluseandmonitoringofrobotsdevelopmentrevealedtheoccurrenceofindustrialrobotswithastructureofkinematicpairslinkagedifferentfromthatcorrespondingtobasicworkspacesase.g.withtheindustrialrobotUM-160orGE-ROBO;theirstructureZKRcanbeexpressed,asseeninFig.4,byakinematicpairslinkageTRR.Practicethereforeprovedtheorythatsetsforn-degreesoffreedomthenumberofpossiblelinkagesofkinematicpairsTandR:m=2n(1)wherenisnaturalnumber.Figure4SchemeofbasickinematicchainofindustrialrobotsUM-160andGE-ROBOForthepracticalandcommonlyusednumberofdegreesoffreedomn=3,thebasicsoanalysednumberoflinkagesisextendedintotaluptom=23=8groups:TTT,RTT,TRT,TTR,RRT,RTR,TRR,RRR.Thissetoflinkageshasalreadyencompassedtheabove-mentionedstructureofrobotfromFig.4;itisthereforepossibletorefertoaderivedstructureofthebasickinematicchainofthisrobotbyvirtueofitskinematicpairs.Eachofkinematicpairs,employedinthebasickinematicchain,canhoweverbefurtherlocatedinoneofthethreedifferentdirectionsgivenbytheCartesiansystemofcoordinatesx,y,zasfollows:translation(T)inthedirectionofcoordinatesX,Y,Z,rotation(R)aroundthesecoordinatesA,B,C,wherefromwithintherespectivelinkages,furtherpossibledifferentarrangementsoriginate,e.g..Tx,Ty,TzincontrasttoTx,Tz,Ty,etc.TheInstituteofProductionMachines,SystemsandRoboticsofFMEBUThasbeenpayingalong-timeattentiontothestudyofarrangementsofpositioningmechanisms.Theuseoftheso–calledcombinatorialalgorithms[1],[2],[5],theirmathematicalexpressionandmorphologicalanalysiswithconstructionalevaluationenabledustoassessthearrangementsinalleightlinkagesandtostatethat-outof165theoreticallypossiblearrangements-47variousnon–isomorphoussolutionscanbeusedforconstructionalpractice.However,someoftheworkspacesthusobtaintheso–called“shell”character.Sofar13arrangementshavebeenusedinpracticeascanbeseenfromthefollowingevaluation:Intotal3+4+5+6+6+10+7+