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ROBOTSGRASPANDMANIPULATEOBJECTSWITHTHEAIDOFAGRIPPERUSUALLYTHEOBJECTISPRESENTEDCOMPLIANCECANBEINTRODUCEDTOTHEROBOTBYUSINGACOMPLIANTENDEffECTORORGRIPPERTHISCANBEDONEINDIffERENTWAYSINLITERATUREAVARIETYOFSUBJECTSONGRIPPERCOMPLIANCECANBEFOUND1,3,4,THESEAREMAINLYFOCUSSEDONCONTROLTHEORIESFORUNIVERSALGRIPPERSANDfiNEMECHANISMANDMACHINETHEORY3820031509–1522CORRESPONDINGAUTHORTEL31152783130；FAX31152781397ATAPREDEfiNEDPICKUPLOCATIONWHERETHEROBOTCANGRASPANDMOVEITTOANOTHERPREDEfiNEDLOCATIONDIffiCULTIESARISEWHENTHEPICKUPLOCATIONANDDESTINATIONAREPARTOFAHEAVYRIGIDBODYTHATCANMOVEDUETOEXTERNALDISTURBANCESIFTHEROBOTCANNOTADAPTTOTHISMOVEMENTDURINGPICKUPORRELEASE,THEFULLFORCEOFTHEMOVEMENTWILLBETRANSFERREDINTOTHEROBOTC213SCOMPONENTS,WHICHCANRESULTINDAMAGETHEREFORETHEROBOTSHOULDBEflEXIBLEORCOMPLIANTWHERETHEENVIRONMENTISSTIff3COMPLIANCEEffECTSINAPARALLELJAWGRIPPERAJGNUTTALL,AJKLEINBRETELERFACULTYOFDESIGN,CONSTRUCTIONANDPRODUCTION,DEPARTMENTOFTRANSPORTATIONTECHNOLOGY,UNIVERSITYOFTECHNOLOGYDELFT,MEKELWEG2,2628CDDELFT,THENETHERLANDSRECEIVED17APRIL2002；RECEIVEDINREVISEDFORM24APRIL2003；ACCEPTED30JUNE2003ABSTRACTTHISPAPERDISCUSSESMECHANICALCOMPLIANCEEffECTSINAGRIPPERWITHPARALLELJAWSINITACASESTUDYOFADEDICATEDGRIPPERDESIGNISPRESENTEDTOANALYSETWODIffERENTDESIGNELEMENTSINflUENCINGTHECOMPLIANTBEHAVIOURTHEflEXIBILITYINTRODUCEDBYPRELOADEDSPRINGSANDTHERESISTANCECAUSEDBYFRICTIONTHEGRIPPERMANIPULATESSEMIAUTOMATICTWISTLOCKSUSEDFORSECURINGSEAGOINGCARGOCONTAINERSTHECOMPLIANCEEffECTSAREEffECTIVETOREDUCEMISALIGNMENTANDOVERLOADOFTHEGRIPPERC2112003ELSEVIERLTDALLRIGHTSRESERVEDKEYWORDSMECHANICALCOMPLIANCE；TWISTLOCKMANIPULATOR；PRELOADEDSPRINGS；FRICTIONFORCE1INTRODUCTIONWWWELSEVIERCOM/LOCATE/MECHMTEMAILADDRESSAJKLEINBRETELERWBMTTUDELFTNLAJKLEINBRETELER0094114X/SEEFRONTMATTERC2112003ELSEVIERLTDALLRIGHTSRESERVEDDOI101016/S0094114X03001009MANIPULATIONIN5,6SUCHACOMPLIANCEISINVESTIGATEDUSINGSTIffNESSMODELSANDIN7AREMOTECOMPLIANCECENTREISINTRODUCEDTHESEINVESTIGATIONSINTEGRATECOMPLIANCEINTOTHECONTROLSYSTEM,WITHTHEAIDOFSPECIALSENSORSANDACTUATORSMAKINGRELIABLEFORCEANDPOSITIONCONTROLPOSSIBLEWITHTHISFORMOFELECTRONICCONTROLTHEUNIVERSALGRIPPERCANMANAGEMANYDIffERENTTASKSANDOBJECTSTHISISINCONTRASTTOTHESPECIALPURPOSEENDEffECTORTHATISTOBEDESIGNEDFORASPECIfiCTASKANDOBJECTBYMAKINGUSEOFSIMPLESENSORSANDACTUATORSCOMBINEDWITHAMECHANICALFORMOFCOMPLIANCEANEffECTIVE,RELIABLEANDROBUSTGRIPPERCANRESULT,WHICHWILLALSOBEABLETOADAPTALLBEITINALIMITEDMANNERTOAMOVINGPICKUPPOINTTHEADAPTATIONOFTHISFORMOFCOMPLIANCEFORGRIPPERCONfiGURATIONSHASPROVENHARDTOfiNDINLITERATURETHISPAPERGIVESANINSIGHTINTOTHEEffECTSOFMECHANICALCOMPLIANCEINAGRIPPERACASESTUDYOFAGRIPPERDESIGNWILLAIDASEXAMPLETODISCUSSTWODIffERENTMODESOFMECHANICALCOMPLIANCETHISEXAMPLECASECONSISTSOFAPARALLELJAWGRIPPERCONfiGURATIONINTENDEDFORTHEMANIPULATIONOFSEMIAUTOMATICTWISTLOCKSOPERATIONIFITISPULLEDTHESHAFTROTATESTHATCONNECTSTHECONESTOGETHER1510AJGNUTTALL,AJKLEINBRETELER/MECHANISMANDMACHINETHEORY3820031509–15222BACKGROUNDTOTHETWISTLOCKMANIPULATORAMANIPULATORWASREQUIREDTOAUTOMATICALLYCONNECTANDREMOVESEMIAUTOMATICTWISTLOCKSTOANDFROMACONTAINERC213SBOTTOMCORNERCASTINGSINFIG1ASEMIAUTOMATICTWISTLOCKISSHOWNONTHELEFTTHISTYPEOFTWISTLOCKISALASHINGDEVICETHATISUSEDTOSECURESEAGOINGCARGOCONTAINERSTOTHEDECKOFASHIPITCONSISTSOFABODY,ANUPPERANDLOWERROTATINGCONEANDAHANDLEFORMANUALOPERATIONOFTHECONEPOSITIONSTHEUPPERCONECANBEINSERTEDINTOTHEBOTTOMCORNERCASTINGDEPICTEDONTHERIGHTSIDEOFFIG1BYUNLOCKINGITTHROUGHROTATINGTHELOWERCONETHETOPCOLLARfiXESINTOTHEHOLEOFTHECORNERCASTING,BECAUSEITMATCHESTHESHAPEOFTHEHOLEWHENTHECONESAREROTATEDBACKTOTHEIRORIGINALPOSITION,THETWISTLOCKISSECUREDTOTHEBOTTOMCORNERCASTINGTHEHANDLEISINTENDEDFORMANUALFIG1ASEMIAUTOMATICTWISTLOCKANDACORNERCASTINGOFACONTAINERFORAUTOMATIONOFTHISSECURINGPROCEDUREANDTHEREVERSEOPERATIONAGRIPPERHADTOBEDESIGNEDTHATCANHOLDDIffERENTTYPESOFTWISTLOCKSBYTHEIRCOLLARSWITHSUffiCIENTGRASPINGFORCE10THEJAWSALSOHAVETOOPENFARENOUGH,TOPREVENTCOLLISIONSWITHTHECONESWHILETHEMANIPULATORISPOSITIONINGOVERTHETWISTLOCKWITHOPENJAWSTHECONTAINERCANMOVEDURINGTHEPICKUPORRELEASEOPERATIONDUETOEXTERNALDISTURBANCES,BECAUSEITWILLBEHOISTEDUPINTHEAIRBYCABLESORRESTINGONAROLLINGCHASSISWITHPNEUMATICTYRESTHEWINDISANEXAMPLEOFADISTURBANCETHATCANGENERATEflUCTUATINGFORCESONTHESIDEOFTHECONTAINER,WHICHCANRESULTINANOSCILLATINGMOVEMENTDUETOTHEPOSSIBLEMOVEMENTOFTHELARGECONTAINERMASS30TONANDTHEROBUSTCONSTRUCTIONOFTHETWISTLOCKTHEGRIPPERWILLHAVETOBECOMPLIANTTOPREVENTDAMAGETOITSELFOROTHERCOMPONENTSOFTHEROBOTMECHANICALCOMPLIANCEWILLALSOHELPTACKLETHEPROBLEMOFTHEMOVINGPICKUPPOINTONTHECONTAINERANDKEEPTHEREQUIREDCONTROLSYSTEMSIMPLECOLLARSIZESHADTOBETAKENINTOACCOUNTFORARELIABLEOPERATIONOFTHEGRIPPERINGENERATEDAJGNUTTALL,AJKLEINBRETELER/MECHANISMANDMACHINETHEORY3820031509–15221511NAMICFORCESCREATEDONTHETWISTLOCKTHETOTALFORCEFTOTTHATHASTOBECOMPENSATEDINADIRECTIONPARALLELTOTHECOLLARSURFACEIS200NTHISWASCALCULATEDBYDETERMININGTHEDYNAMICFORCESCAUSEDBYMOVEMENTOFTHEMANIPULATORANDTHESTATICGRAVITATIONALFORCEWITHAFRICTIONALCOEffiCIENTLOF0125THEGRASPINGFORCEEXERTEDBYEACHJAWFJAWCANBECALC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