外文翻译--自动焊接操作系统.doc

AnautomatedweldingoperationplanningsystemforblockassemblyinshipbuildingKyu-KabCho*,Jung-GuySun,Jung-SooOhAbstractTheblockassemblyprocessisoneofthemostimportantmanufacturingprocessesforshipbuilding.Sinceblockiscomposedofseveralsteelplatesandsteelsectionswithpredeterminedshapesaccordingtoshipdesign,theweldingoperationplanningtoconstructablockisacriticalactivityforshipbuilding,butthisactivityhastraditionallybeenexperiencebased.Thus,itisrequiredtodevelopanautomatedweldingoperationplanningsystemtoassembleblocks.Thispaperdescribesthedevelopmentofanautomatedweldingoperationplanningsystemforblockassemblyinshipbuilding.Basedontheinformationaboutparts,topologicalrelationshipbetweenpartsandassemblysequencesforblock,thedevelopedsystemperformsthedeterminationofweldingpostures,weldingmethods,weldingequipmentandweldingmaterials.Thedevelopedsystemimplementedsuccessfullyforrealblocksconstructedinshipyard.Keywords:Blockassembly；Expertsystem；Operationplanning；Weldingprocess1.IntroductionShipbuildingistraditionallyalabor-intensiveassemblyindustrythatemploystheweldingprocessasabasicproductiontechnology.Inshipbuilding,thereareseveraltypesofmanufacturingprocessplanningforcuttingandbending,assembly,out-fitting,anderection.Amongtheseprocessplanningactivities,theassemblyprocessplanningisbyfarthemostimportant,sincetheconstructionprocessforahullblockcomprisesapproximately4850%ofthetotalshipbuildingprocess1,2.Themainoperationforblockassemblyistheweldingoperation.Theweldingoperationplanningproblemsinblockassemblyareverydifficulttosolvebecauseallblocksaredifferentinsize,type,andconstitutingsub-assembliesthatdependonthetypesofships.Also,sincethisactivityhastraditionallybeenexperienced-based,weldingoperationplanninginshipbuildinghasbeenperformedmanually.Thus,itisveryimportanttodevelopanautomatedweldingoperationplanningsystemforshipbuilding.Thereisrelativelyverylittleliteratureavailableonautomatedweldingoperationplanningsystemsforshipbuilding3,4.Thispaperdealswiththedevelopmentofanautomatedweldingoperationplanningsystemforblockassemblyinshipbuilding.Therule-basedexpertsystemforweldingoperationshasbeendevelopedusingSmartElementsasanexpertsystemtool.Thedevelopedsystemisdemonstratedandverifiedbyusingactualblocksintheshipyard.2.Developmentofanautomatedweldingoperationplanningsystem2.1.SystemframeworkTheautomatedweldingoperationplanningsystemdevelopedinthispaperconsistsoffourmodules:weldingposturesmodule,weldingmethodsmodule,weldingequipmentmodule,andweldingmaterialsmodule.TheframeworkofthissystemisshowninFig.1.2.2.DeterminationofweldingposturesThismoduledeterminesthepostureoftheweldingoperator.Weldingpostureisreasonedbyconsideringconnectiontypesandpositionaldirectionbetweentwoconnectedparts,directioninformationofassemblybasepart,existenceofturnover,andassemblylevel.Connectiontypesareclassifiedintobutttype(B)andfillettype(T),asshowninFig.2.Thefourtypesofweldingpostures,downposture(D),overheadposture(O),horizontalposture(H),andverticalposture(V),areconsideredinthispaper,asshowninFig.25,6.Themoststableandeasiestweldingpostureisthedownweldingposture,andthemostdifficultoneistheoverheadweldingposture.Theweldingoperatordeterminesanefficientweldingpostureaccordingtotheworkingconditions.Forrelationshipofconnectionbetweentwopartsthatarewelded,onepartisconsideredasthebaseandtheotherisconnectedtothebase.ThepartthatisconsideredasabaseisrepresentedasPartFromandtheotherthatisconnectedtothebaseisrepresentedasPartTo.Thelevelsofblockassemblytoassemblesteelplatesandsectionsintothefinalblockareclassifiedintosubassembly(SA)level,unitblockassembly(UBA)level,andfinalblockassembly(FBA)level.Subassemblylevelsmaybedividedintosmallsubassembly(SSA)levelsandintermediatesubassembly(ISA)levelsaccordingtothesizeandweightofthesubassemblyasshowninFig.3.Fordeterminingweldingpostures,theblockassemblylevelsareclassifiedintotwogroups.Thefirstgroupisthesmallsubassemblylevel；thesecondgroupconsistsoftheintermediatesubassembly,theunitblockassembly,andthefinalblockassemblylevels.Thereasonforthisgroupingisthatthereisnoturnoverprocessinthesmallsubassemblylevel,buttheassemblylevelsbelongingtothesecondgroupmayhaveturnoverprocesses.Turnoverprocessescausethechangeofweldingposturesthataredeterminedbeforetheturnoverprocess.2.2.1.DeterminingweldingposturesinthefirstgrouplevelThefollowingareexamplesofrulestodeterminetheweldingpostureforasmallsubassemblylevel.Theconnectiontypesofweldingjoint