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附录1：翻译（英文）ModelingandspecifcationsofdynamicagentsinfractalmanufacturingsystemsKwangyeolRyua,YoungjunSonb,MooyoungJunga,*aDepartmentofIndustrialEngineering,PohangUniversityofScienceandTechnology,Pohang,SouthKoreaSystemsandIndustrialEngineeringDepartment,TheUniversityofArizona,Tucson,AZ,USAbReceived9September2002；accepted16April2003AbstractInordertorespondtoarapidlychangingmanufacturingenvironmentandmarket,manufacturingsystemsmustbeflexible,adaptable,andreusable.Thefractalmanufacturingsystem(FrMS)isoneofthenewmanufacturingparadigmsthataddresstheneedforthesecharacteristics.TheFrMSiscomprisedofanumberof‘‘basiccomponents’’,eachofwhichconsistsoffivefunctionalmodules:(1)anobserver,(2)ananalyzer,(3)anorganizer,(4)aresolver,and(5)areporter.Eachofthesemodules,usingagenttechnology,autonomouslycooperatesandnegotiateswithotherswhileprocessingitsownjobs.Theresultingarchitecturehasahighdegreeofself-similarity,oneofthemaincharacteristicsofafractal.DespitethemanyconceptualadvantagesoftheFrMS,ithasnotbeensuccessfullyelaboratedandimplementedtodatebecauseofthedifficultiesinvolvedindoingso.Inthispaper,thestaticfunctionsanddynamicactivitiesofeachagentaremodeledusingtheunifiedmodelinglanguage(UML).Then,relationshipsamongagents,workingmechanismsofeachagent,andseveralfractal-specificcharacteristics(selfsimilarity,self-organization,andgoal-orientation)aremodeledusingtheUML.Then,amethodfordealingwithseveraltypesofinformationsuchasproducts,orders,andresourcesintheFrMSispresented.Finally,apreliminaryprototypefortheFrMSusingAgletsTMispresented.#2003ElsevierB.V.Allrightsreserved.Keywords:Fractalmanufacturingsystem(FrMS)；Agenttechnology；UML；ModelingAbbreviations:FrMS,fractalmanufacturingsystem；BFU,basicfractalunit；DRP,dynamicrestructuringprocess；UML,uni?edmodelinglanguage；HMS,holonicmanufacturingsystem；BMS,bionic/biologicalmanufacturingsystem；CNP,contractnetprotocol；MANPro,mobileagent-basednegotiationprocess；NMA,networkmonitoringagent；EMA,equipmentmonitoringagent；SEA,scheduleevaluationagent；DRA,dispatching-ruleratingagent；RSA,real-timesimulationagent；SGA,schedulegenerationagent；GFA,goalformationagent；TGA,taskgoverningagent；NEA,negotiationagent；KDA,knowledgedatabaseagent；DMA,decision-makingagent；FSM,fractalstatusmanager；FAM,fractaladdressmanager；REA,restructuringagent；NCA,networkcommandagent；ECA,equipmentcommandagent；STA,systemagent；NTA,networkagent；MP,materialprocessor；MH,materialhandler；MT,materialtransporter；BS,bufferstorage；MRP,materialremovalprocessor；MFP,materialformingprocessor；MIP,materialinspectionprocessor；PD,passivedevice；FMH,?xedmaterialhandler；MMH,movablematerialhandler；FMT,fixedmaterialtransporter；MMT,movablematerialtransporter；ABS,activebufferstorage；PBS,passivebufferstorageE-mailaddress:myjung@postech.ac.kr(M.Jung).*Correspondingauthor.Tel.:t82-54-279-2191；fax:t82-54-279-5998.0166-3615/$–seefrontmatter#2003ElsevierB.V.Allrightsreserved.doi:10.1016/S0166-3615(03)00099-X1.IntroductionFacingintensifiedcompetitioninagrowingglobalmarket,manufacturingenterpriseshavebeenreengineeringtheirproductionsystemstoachievecomputerintegratedmanufacturing(CIM).MajorgoalsofCIMinclude,butarenotnecessarilylimitedto,loweringmanufacturingcosts,rapidlyrespondingtochangingcustomerdemands,shorteningleadtimes,andincreasingthequalityofproducts[1–3].However,thedevelopmentofaCIMsystemisanincrediblycomplexactivity,andtheevolutiontoCIMhasbeenslowerthanexpected[4,5].Thiscanbedirectlyattributedtohighsoftwaredevelopmentandmaintenancecosts.Therefore,inordertoachieveacompetitiveadvantageintheturbulentglobalmarket,themanufacturingenterprisemustchangemanufacturingprocessesfromallanglesincludingordering,productdesign,processplanning,production,sales,etc.AsacontrolmodelforimplementingCIMsystems,hierarchicaldecompositionofshopflooractivitieshasbeencommonlyusedintheshopfloorcontrolsystem(SFCS),thecentralpartofaCIMsystem[2].Generally,acentraldatabaseprovidesaglobalviewoftheoverallsystem,andcontrollersgenerateschedulesandexecutethem.Hierarchicalcontroliseasytounderstandandislessredundantthanotherdistributedcontrolarchitecturessuchasheterarchicalcontrol.However,ithasacrucialweakpoint,whichisthatasmallchangeinonelevelmaysignificantlyandadverselyaffecttheotherlevelsinthehierarchy.Therefore,itisnormallysaidthathierarchicalcontrolofCIMsystemsismuchmoresuitableforproductioninasteadyenvironmentthaninadynamicallychangingenvironmentbecauseitissodiffculttoapplycontrolhierarchychangesimmediatelytotheequipment.Furthermore,itisdiffculttomeetdynamicallychangingcustomerrequirementsbecausethehierarchicalcontrolarchitectureisnotflexibleenoughtohandlethereconfigurationoftheshop.Therefore,themanufacturingsystemoftomorrowshouldbeflexible,highlyreconfigurable,andeasilyadaptabletothedynamicenvironment.Furthermore,itshouldbeanintelligent,autonomous,anddistributedsystemcomposedofindependentfunctionalmodules.Tocopewiththeserequirements,newmanufacturingparadigmssuchasabionic/biologicalmanufacturingsystem(BMS)[6,7],aholonicmanufacturingsystem(HMS)[8,9],andafractalmanufacturingsystem(FrMS)[10–13]havebeenproposed.Tharumarajahetal.[14]provideacomprehensivecomparisonamongaBMS,aHMS,andanFrMSintermsofdesignandoperationalfeatures.AnFrMSisanewmanufacturingconceptderivedfromthefractalfactoryintroducedbyWarnecke[13].Itisbasedontheconceptofautonomouslycooperatingmulti-agentsreferredtoasfractals.ThebasiccomponentoftheFrMS,referredtoasabasicfractalunit(BFU),consistsoffivefunctionalmodulesincludinganobserver,ananalyzer,aresolver,anorganizer,andareporter[10,11].ThefractalarchitecturalmodelrepresentsahierarchicalstructurebuiltfromtheelementsofaBFU,andthedesignofabasicunitincorporatesasetofpertinentattributesthatcanfullyrepresentanylevelinthehierarchy[12].Inotherwords,theterm‘fractal’canrepresentanentiremanufacturingshopatthehighestleveloraphysicalmachineatthebottom-level.EachBFUprovidesservicesaccordingtoanindividual-levelgoalandactsindependentlywhileattemptingtoachievetheshoplevelgoal.AnFrMShasmanyadvantagesforadistributedanddynamicmanufacturingenvironment.Automaticreconfigurationofasystemthroughadynamicrestructuringprocess(DRP)isthemostdistinctivecharacteristicoftheFrMS.Inthispaper,thescopeofthereconfigurationdoesnotincludereconfigurablehardware[15]andexternallayoutdesign.Rather,itfocusesontheinteriorstructureofsoftwarecomponentsthatcanbereorganizedwithsoftwaremanipulations.Thereconfigurationorrestructuringinthispaperconsidersbothdynamicclusteringoftheagentsandconstruction/destruction/cloningofagents,whichaffectthenumberofagentsinthesystem.ThefunctionofafractalisnotspecificallydesignatedatthetimeofitsfirstinstallationintheFrMS.Thereconfigurationaddressedinthispaperalsoincludessituationswheretheagents’enrollmentsarechanged,meaningthattheagentsareassignedanewgoalandnewjobs,buttheircompositiondoesnotchange.Thispaperfocusesonformalmodelingofagentsandfractal-specificcharacteristicsthatwillprovideafoundationforthedevelopmentoftheFrMS.Becauseassociateddifficultieshave,todate,preventedafractal-basedsystemfrombeingembodied,itisnecessarytofirstexplicitlydefineaconcept,mechanisms,andcharacteristics.Theobjectiveofthispaper,therefore,istoclearlydefineandmodelfractal-specifccharacteristicsforamanufacturingsystemtohavesuchcharacteristics.Inordertodeveloptheagents,interandintra-fractalactivitiesarefirstclarified.Then,dynamicactivitiesforeachagentandrelationshipsbetweenagentsaremodeled.InordertomorefullydeveloptheFrMS,severalfractal-specificcharacteristicsarealsomodeled.Tosupportembodimentofmodeledcharacteristics,amethodfordealingwithinformationaboutproducts,orders,andresourcesintheFrMSisinvestigated.Throughthisresearch,mechanismsofagentsandcharacteristicsoftheFrMScanbedescribedwithsimplediagramsthatmakethesystemeasiertounderstand.TheworkcontainedinthispaperextendstheFrMSfrompreviouspapersbyemphasizinganddetailingitscharacteristics.Theactivitiesofagentsarespecifiedusingactivitymodelssothattheagentscanusetheactivitymodelstoforecasttheirnextactivitiesatrun-time.Therestofthispaperisorganizedasfollows:Section2describesfunctionsanddynamicactivitiesofagentsusingfunctionalandactivitymodelsofunifiedmodelinglanguage(UML).InSection3,inter-andintra-fractalactivitiesarespecified.Severalfractal-specificcharacteristicsaredescribedusingUMLmodelsinSection4.Section5describesamethodfordealingwithinformationaboutproductsandresourcesintheFrMS.Section6concludesthepaper.2.Agent-basedfractalmanufacturingsystem(FrMS)2.1.BackgroundofanFrMSAnoverviewoftheFrMSisdepictedinFig.1.Everycontrollerateverylevelinthesystemhasaselfsimilarfunctionalstructurecomposedoffunctionalmodules.Inaddition,eachofthesemodules,regardlessofitshierarchicallevel,consistsofasetofagents.Aftertheinitialsetupofasystem,theconfigurationofthesystemmayneedtobereorganizedinresponsetounexpectedeventssuchasmachinebreakdown.Thesystemwillalsoneedtobereconfiguredwhenthesetofpartstobeproducedinthesystemchangesduetoachangeincustomerneeds.Inthesecases,fractalsintheFrMSautonomouslyanddynamicallychangetheirstructure,viatheactionsofagentsfortheappropriateworkingmechanismsofthefractals.Fig.1showstwofacilitylayoutsandthecorrespondingcompositionsoffractalsbeforeandaftertherestructuringprocess.Whenamachine(M)andarobot(R3)areaddedtothesystem,fractalsreorganizetheirinteriorconfigurationswiththemechanismofdynamicrestructuringprocessinawaythatthesystemcontinuestoworkwithgreatestefficiency.AfractalconsistsoffivefunctionalmodulesillustratedwiththeirrelationshipsinFig.2.Thefunctionsofeachmodulecanbedefineddependingupontheapplicationdomain.Fig.1.ReorganizationofthesystemusingadynamicrestructuringprocessintheFrMS.However,whenthetargetdomainisdetermined,themainfunctionsofeachmodulewillbeconsistentthroughoutthesystem.Forexample,thefunctionofaresolvermaybedifferentdependinguponwhetheritisdefinedforcontrollingamanufacturingsystemorformanagingsupplychains.However,themainfunctionofaresolverinamanufacturingsystemissimilartootherresolversinthatsystemregardlessoftheirlevelinthehierarchy.Abottom-levelfractalhassimilarfunctionstothoseofaconventionalequipmentcontrollerinaSFCS.Afractal,whichisdirectlyconnectedtoequipment(e.g.machine,robot,etc.),receivessensorysignalsofequipmentandreturnsmessagesorcommands.Thefunctionofanobserveristomonitorthestateoftheunit,toreceivemessagesandinformationfromouterfractals,andto

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