济南大学毕业设计外文资料翻译 模板 理工类.docx

济南大学毕业设计外文资料翻译 模板 理工类.docx

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济南大学毕业设计外文资料翻译模板理工类

毕业设计外文资料翻译

题目人工和工业机器人重复操作定位

学院机械工程学院

专业机械工程及自动化

班级

学生

学号

指导教师

二〇一四年三月三十日

ComputersinBiologyandMedicine28（1998）415-421

Comparisonofpositionrepeatabilityofahumanoperatorandanindustrialmanipulatingrobot

JureZupancic*,TadejBajd

FacultyofElectricalEngineering,UniversityofLjubljana,TrzÏasÏka25,SI-1000Ljubljana,Slovenia

Received8December1997

AbstractRobotperformancecriteriaofpositionrepeatabilityarestudied.Weight-to-payloadratioisinmanipulatingrobotssignificantlyhigherthaninhumanoperators.Bracingstrategyimprovingtherobotperformancesisintroducedinthepaper.Thestrategycopieshumanbehaviorduringfinemotionoperations.Acomparisonismadebetweentherobotandthehumanoperatorperformingapproximatelythesamemanipulatingtask.ContactlessmeasurementsofpositionrepeatabilitywereaccomplishedwiththeOPTOTRAK®motionanalysissystem.Theresultsoftestsdemonstrateconsiderableimprovementofrobotandhumanoperator'spositionrepeatabilitywhenusingbracing.

©1998ElsevierScienceLtd.Allrightsreserved.

Keywords:

Industrialrobot;Humanoperator;Repeatability;Standards;Measurements;Bracingstrategy

1Introduction

Modernrobotmanipulatorsreplacinghumanoperatorinassemblytasks[1]areusuallydesignedinaccordancewiththeprinciplesencounteredinhumansandtheirarmsandhands.Themaingoalofdevelopingamechanicalcounterparttohumanoperatorisachievingofimprovedperformancessuchasspeed,payloadcapacity,positionaccuracyandrepeatability.However,whentheloadsarenotexceeding3kilograms,weight-to-payloadratiofoundinrobotsisreportedtobetentimeshigherthanthesameratioassessedinhumanoperator[2].Thereductionofthisratioishighlyrelatedtooverallrobotefficiencyfromtechnicalandeconomicalpointofview.Traditionalprinciplesforimprovingthisratioareintroducinglightermaterials[3],newconstructionsolutionsanddesignofnewactuators.

Inaspecialcase,itispossibletoincreasetherobotabsoluteaccuracyandrepeatabilitybyusingappropriatebracing[4].Themethodofbracing[5]isadirectcopyofhumanbehaviorwheretheadaptationtohigheraccuracyandrepeatabilityrequirementsduringthefinemotionoperationisrequired.Ahumanoperator,whenperformingprecisemanipulationtasks,oftenfindssupportsforhisforearm,wristorelbowlikeinmanyworkingsituationswatch-makersarepracticing.Thesamesimpleideacanbetransferredintorobotics.

Apartfromsomeestimations,therewasnoexplicitcomparisonmadebetweenhumanoperatorandadequaterobotperformances.Theaimofthisinvestigationwastomakeconcisetechnicalcomparisonofrobotandhumanoperatorperformancewithandwithoutbracing.

2Method

PositionrepeatabilitytestswereperformedinaccordancewithISO9283standardformanipulatingindustrialrobots[6].Thecubewithmaximumvolumewaslocatedintheworkspaceofthemostfrequentanticipateduse.Fivepoints（P1-P5）werelocatedonthediagonalsoftheselectedplaneasshowninFig.1.ContactlessOPTOTRAK®/3010motionanalysissystemwasusedformeasuringoftheactualpositions（seeFig.2）.MeasurementsweretakenattheposesP1,P2,P3,P4andP5.Thepositionrepeatabilityexpressestheclosenessoftheattainedpositionsafter30repeatedvisitstothesamecommandedposition,asrequiredbytheISO9283standard.Therepeatabilityiscalculatedbythefollowingequations:

（1）

（2）

（3）

Fig.1.Definitionofthemeasuringpoints（P1-P5）insidetherobotworkspace.

Fig.2.Measuringequipmentforpositionrepeatabilitytesting.

（4）

wherexj,yj,zjrepresentnominalpositions,

meanactualpositionsandSDisthepositionalstandarddeviation.

Therepeatabilitytestsweremadefor

（1）robot,

（2）bracedrobot,（3）humanoperatorand（4）humanoperatorwithhisforearmsbraced.Incases

（1）and

（2）thenominalposeswerecommandedbytherobotprogram.Thesamestandardrequirementswereinvolvedinthetestswithhumanoperator.Thenominalposeswerecommandedbyawireframewithfiveringtargetswhichwerepositionedintotheworkingspaceoftheoperator.Theoperatorheldinhishandthesamemeasuringrigidbodyastherobot.Approximatelythesamevolumeoftheworkingspacewaschosenfortheoperatorasfortherobot.

Asaddleshapedsupportbodywasusedincase

（2）.Incase（4）ahorizontalbarwasusedtosupportthehumanoperator'sforearm.ThefourmeasuringsituationsareshowninFig.3.

3Testingandresults

AseaIrb6industrialmanipulatingrobotwastestedinourexperiments.Additionalsegmentwasattachedtotherobotenablingbracingagainstthesupportbody.Forthecase

（1）（Fig.3a）theweightofadditionalsegmentwas1.65kg,whileinthecase

（2）（Fig.3c）itwas2.15kg.Thedifferencewasduetotheconstructiondetailsofabracingsegment.Theweightofthemeasuringrigidbodyheldbyhumanoperatorwas0.8kg.Threepersonsweretested.5%ofthetotalhumanoperator'sweightwasassumedasarmweight.Additionaldummyweightwiththemassof0.9kgwasattachedtothehuman'shandsimulatingthesametoolasheldbytherobot.Approximateweight-to-payloadratioswere（a）freerobot82,（b）humanoperator2.4,（c）bracedrobot62,（d）humanoperatorwithbracing5.

Fig.3Fourtypesofmeasurements（a）freerobot,（b）humanoperator,（c）bracedrobotand（d）humanoperatorwithbracedforearm.

Fig.4Theresultsoftherepeatabilitytestinfreerobotandbracedrobot.

Fig.5Theresultsoftherepeatabilitytestinfreehumanoperatorandwithbracing.

Inthenextfourhistograms（Figs.4and5）theresultsofthepositionrepeatabilityforthefourspecifiedtypesoftestingarepresented.

Therepeatabilityofthebracedrobotascomparedtothefreerobotwasimprovedforapproximately50%.Thesameimprovementinthehumanoperatorwasforabout25%.Note,thattheweight-to-payloadratioforrobotwasmorethan10_higherthanforhumanoperator.

4Conclusion

Applyingbracingstrategyduringrobotmanipulationisacopyofhumanbehavior.Positionrepeatabilityperformancecriteriawerestudied.RepeatabilitymeasurementsaccordingtoISO9283wereperformedwithindustrialmanipulatingrobot.Forthefirsttime,thesamemeasurementofpositionrepeatabilityunderconditionofISO9238standardwasusedinthetestofahumanoperatorperformance.Theresultsshowsignificantimprovementofpositionrepeatabilityincaseswhentherobotandthehumanoperatorarebracedagainstthesupportingbody.Thecomparativestudyencouragedresearchersforfurtherinvestigationofbracingstrategy[7].Sameapproachestohumanoperatorpositionrepeatabilityassessmentcouldbeappliedalsoinergonomicstudies.

5Summary

Theindustrialmanipulatingrobotsareusuallymoreorlessaccuratestructuralcopiesofhumanoperator'sarmsandhands.Structuralcopyingofthenaturalmechanismsalonedoesnotalwaysgivesatisfyingresults,hencethemodernroboticmanipulatorswithmaximumratedloadsbelow3kgaremechanicallyinferiortohumanoperators.Bracingstrategywhichisusedforimprovingparticularrobotperformancesisthecombinationofthestructuralandfunctionalcopyingofnaturalhumanbehavior.Ahumanoperator,whenperformingprecisemanipulationtasksoftenfindssupportsforhisforearm,wristorelbowlikeinmanysituationswatch-makersarepracticing.Thesamesimpleideacanbetransferredintoroboticswiththeaimoftemporarilyimprovementofrobotcharacteristicssuchasaccuracy,repeatability,stiffness,payloadcapacityandmechanicalvibrations.

Theobjectiveofourresearchwastogetconcisetechnicalcomparisonbetweentherobotandhumanoperator'sperformancesconcerningpositionalrepeatability.ISO9283standardformanipulatingindustrialrobotperformancecriteriaandrelatedtestmethodswasthebasisforthecomparativestudy.Thetestingequipmentwasbuiltaroundthecontactless3-DmotionanalysissystemOPTOTRAK®/3010（NorthernDigital）.ThepositionrepeatabilitytestswereperformedfortherobotAseaIrb6andthehumanoperatoraccomplishingsimilarmanipulatingtaskunderthesameconditions.Humanandrobotoperationsinfreeandbracedconditionweretested.Positionrepeatabilityofthebracedrobotascomparedtofreerobotwasimprovedforapproximately50%.Thesameimprovementinhumanoperatorwasabout25%.Weight-to-payloadratioforrobotwasmorethan10_higherthanforhumanoperator.Theresultsofthestudyencouragedresearchersforfurtherinvestigationofthekinematicsofabracedrobot.Thepotentialuseoftheobtainedresultsinergonomicstudiesissuggested.

Acknowledgements

ThisworkwaspartlysponsoredbytheSlovenianMinistryofScienceandTechnology.TheauthorswishtoacknowledgethecontributionofDanaMaurovicÏandIvanLoncÏarperformingthedescribedmeasurements.

References

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[2]E.I.Rivin,Mechanicaldesignofrobots,Mc.Graw-Hill,1988.

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Proceedingsofthe2ndInternationalConferenceonRobotics,Dubrovnik,1989,pp.361-372.

[4]J.ZupancÏicÏ,Enhancingrobotmechanismperformancesbyusingmechanicalsupport:

kinematicanalysis,in:

Proceedingsofthe3rdInternationalWorkshoponAdvancesinRobotKinematics,Ferrara,Italy,1992,pp.297-303.

[5]W.Book,S.Le,V.Sangveraphunsiri,Bracingstrategyforrobotoperation,in:

ProceedingsoftheSymposiumontheTheoryandPracticeofRobotsandManipulators,Udine,1984,pp.179-185.

[6]Manipulatingindustrialrobots:

performancecriteria