外文翻译--工程师的CAx培训--不仅仅是CAD 英文版.pdf -- 5 元

EngineersCAxeducationitsnotonlyCADC.WernerDankwort,RolandWeidlich,BirgitGuenther,JoergE.BlaurockUniversityofKaiserslautern,ResearchGroupforComputerApplicationandEngineeringDesign,P.O.Box3049,Kaiserlautern67663,GermanyReceived30January2004accepted23February2004AbstractThegeneralproductdevelopmentcanbedividedintothreephasescreative,conceptualandengineeringphase.AllphasesofthecompletelifecycleofaproductaresupportedbyvariousITsystemsoftencalledCAx1systems.ThereforeCADeducationshouldbeextendedtoCAxeducationandpayattentiontoallphasesofthelifecycle.WhenlookingattodaysprocesschainmanydifferentjobsrelatedtoCAxcanbeidentified.Allofthemrequiredifferentlevelsofknowledgeaboutsubjectslikeinformationtechnology,designproceduresorCAGD2functionalities.Themethodstoteachthosesubjectsvaryfromsimpleautodidactic,viacomputersupportedtrainingmethodstointeractivepersontopersontraining.Inindustry,thetrainingmethodsareprimarilydependingonthecompanyssizeandbranch.Thebiggerthecompanyis,themorecomplexarethetrainingmethodsandthemorespecializedistheCAxeducation.EnterprisesspecialisedonCAxtrainingbutalsoinhouseeducationdepartmentsareconcerned.OtherpossibilitiesforCAxeducationareinternships,technicalcollegesanduniversities.Allofthosesufferfromthecomplexityofthesubjectandresultofteninbroadbutsuperficialeducation.ApartfromknowledgeaboutCAxsystemsandtheirusage,thestudentshavetolearnalsoabouttheorganisationoftheCAxprocessanditsstructuresincludingthecooperationofenterprises.FollowingtheseexperiencesthestudentsoremployeeswillatfirstbetrainedinfundamentalCAS/CAD/CAM.InasecondsteptheywillattendspecialcoursesforPDM,Dataexchange,FEM,orothers.OnhigherleveltherewillbecoursesdealingwithPLM3,processandcompanynetworks,withfuturetrendsandtechniques.Duringthewholeeducationtheapplicationaspecthastobedominant.q2004ElsevierLtd.Allrightsreserved.KeywordsCAxjobprofilesHumanfactorsTrainingmethodsCAxeducationinindustryCAxeducationinuniversities1.MotivationInanewsletteroftheyear1999fromSolidWorksthefollowingquestionwasraisedWhatisthemostimportantlearningobjectiveTheanswergivenwasToteachthatdesignisaprocessLateroninthisnewsletteritwassaidthatengineeringeducationissupposedtoeducateengineersinhowtothinkinthemodernworldofproductdesignandmanufacturing1WhatdoesthismeanforCADeducationinindustry,atschoolsanduniversitiesItcertainlydoesnotmeanthatCADeducationisonlyrestrictedtoteachingsolidorsurfacemodelling.ThetaskisquitemorecomplexthestudentortechnicalemployeehastolearnaboutthecompletedevelopmentprocessundertheaspectofComputerAidedProductCreation.2.AbriefhistoryofCADsystemsModernCAxsystemshavevariousroots†TheAutomaticProgrammingToolAPTdevelopedbyRossatMITinthe1950stocontrolmachinesnumerically.ThiscanberegardedastheprecursorofmodernCAMsystems.†TheearlycomputeraideddraftingsystemslikeCADAMfromLockheedMartinweredevelopedto00104485//seefrontmatterq2004ElsevierLtd.Allrightsreserved.doi10.1016/j.cad.2004.02.011ComputerAidedDesign3620041439–1450www.elsevier.com/locate/cadCorrespondingauthor.Tel.þ496312053686faxþ496312053872.Emailaddressweidlichmv.unikl.deR.Weidlich.1CAxSummarisedCAD,CAM,CAS,CAQ,2CAGDComputerAidedGeometricDesign3PDMProductDataManagement,PLMProductLifecycleManagementreducetimeandmoneybyreplacingtheconventionaldrawingboardinthe1970s.†Theearlysystemsforthecreationofsculpturedsurfacesoriginallyweredevelopedfortheautomobileandthehelicopterindustry.Themotivationforthisdevelopmentwasnotthereductionintimebutadistinct3DrepresentationofsculpturedsurfaceswhichthencouldbeusedforNCmilling.This3Dsurfacerepresentationcouldnotbecreatedwithconventional2Ddrawingsandcutsections.†ComputerAidedEngineeringbyFiniteElementMethodsbeganinthe1960swithNastran,followedbyMarcandAnsysinthe1970s.FromtheserootsmoreandmoretasksinthedesignprocessweresupportedbyCAxtoolsduringthelast30years.Startingwithdraftingandsurfacingalsoclassicalmechanicaldesignwasreplacedby3Dwireframe,solidmodellingandparametricandfeaturebaseddesign.Todaythecompleteproductcreationprocess,includingproductionpreparation,iscompletelyrunningwithCAxtechniques.AccordingtothevariousapplicationfieldsdifferentCAxsystemsweredeveloped,namedbydifferentCAxmethodsComputerAidedStylingCAS,ComputerAidedAestheticDesignCAAD,ComputerAidedConceptualDesignCACD.AllthesetechnologiesarecoveredbytheexpressionComputerAidedDesignCAD.TwoveryimportantCAfieldswerehistoricallydevelopedalmostindependentlyComputerAidedManufacturingCAMandComputerAidedEngineeringCAE.ThelastismainlyusedinalimitedsenseforsimulationandFiniteElementAnalysis.AlthoughstartingindependentlythesetechnologiessoonaskedforinputdatafromCAD,IDEAS,developedinthemid1970shasitsrootinthelinkofCADandFEA.WiththegrowingintegrationoftheseCAxtoolsthedataandinformationmanagementbecamemoreandmoreimportant.NowadaysthecomplexnetworkofCAxsystemsandtheirvariousdatacannotbehandledwithoutProductDataManagementSystemsPDMS.Theyareregardedasthebackboneofmodernproductdevelopmentandnowextendedtosupportthewholeproductlifecycle.ThisoverallinformationmanagementleadstotheconceptofProductLifecycleManagementPLM.EducationconcerningComputerAidedProductCreationstilldoesreflectthishistoryStudentsorengineersusuallystarttheireducationwith2Dsystems.Subsequentlytheyareintroducedto3Dmodelling.Furtherontheyarefamiliarizedwithparametricandvariationaldesign.ParalleltheyhavetobetrainedinPDMorPLMsystemstohandlealltheCAxdata.3.TodaysprocesschainInanexemplarysimplifiedprocesschainseeFig.1itisshownthatCADisonlyapartoftheproductdevelopmentprocess.Thisprocessbeginswithanidea,requirementsandspecificationsfortheproductandendswiththeserialproduction,customeraftersalesservice,recycling,scrappinganddisposal.CADisembeddedinthedevelopmentprocesstogetherwithmanyotherCAxtechnologies.InorderFig.1.Generalprocesschainofproductdevelopment2.C.W.Dankwortetal./ComputerAidedDesign3620041439–14501440toavoidunnecessaryloopstheengineerhastohaveknowledgeofthesurroundingprocessstepsaswellasthekindandqualityofdata,respectivelyinformation,theyproduceorrequire.Theknowledgeaboutthepreviousprocessstepsistomaintainthedesignintend,theknowledgeaboutthefollowingprocessstepsistoguaranteetheirfeasibility.Inadditiontothiseconomicalaspectthequalityoftheproductdescribinginformationhastobetakenintoaccount.Themodernproductcreationprocessproceedsmoreandmoreasavirtualproductgenerationprocess.KeepinginmindthattheprocessesarecharacterizedbySimultaneousEngineeringperformingdifferentprocessstepsatthesametimeandConcurrentEngineeringdevelopingneighbouringcomponentsinparallel,itisobvious,thatanenormousamountofdataproducedhastobehandledbyanefficientproductdatamanagementsystemPDM.Twofactsincreasethecomplexityofthesituation†FordifferenttaskswithinoneorvariousprocessstepssometimesquitedifferentCAxsystemshavetobeusedwithquitedifferentdatamodels.†Inmodernindustryanetworkofsuppliersisinvolved,oftenworkingwithdifferentsystemsordifferentversionsofthesamesystem.ThereforenotonlyCAxdataexchangewithdataconversionisakeytaskforsuccessfuldevelopmentandproductionprocessesbutalsothecompletesupplierintegration.4.CAxpeoplevariousjobprofilesWhenlookingatthehistoryofCAD,thefirstusersofCAtoolsinthe1970swereCADdraftsmenandCADsurfacedesignerforcarbodiesorhelicoptershellstodayoftencalledsurfacer.Alreadyinthe1970sthesurfaceswereuseddirectlyforNCmillingofsurfaces,whiletheFEAengineerusedtheCADgeometryasinput.Draftsmanandsurfacersweretrainedprimarilybysystemsuppliersand/orbyaninhouseCADtechnician.TheseCADtechniciansoftenhavebeenpilotusers,trainers,andinhousesystemsupportersatthesametime.Thesepioneersmadethenewtechniquepresentableandreducedprejudices,whichhadbeenraisedbytheconventionaldevelopment.WiththegrowingcapabilitiesoftheCADsystemsinthefirsthalfofthe1980sthenumberofdifferentCADpeoplegrew.Inthe1990sthescopeofCAxtoolsincreasedandtodayCAxtechnologyismoreorlessstandard.NowadaystheintensiveusageofCAxtechnologiescanberegardedasapreconditionforanycompetitivecompany.Asaconsequencethevarioustaskscausevariousjobs.FollowingtheprocesschainthereareseeFig.1†Stylists,whoworkmanually,sketchingandmodellingwithclay,butalsomoreandmorewithCASsystemslikeALIAS†Surfacers,whotransfertheshapes,designedbythestylists,toCAClassAsurfaces.TheyusespecialsurfacesystemslikeICEMSurforinformertimesSTRIM100.†CNCModelmakers,whouseCAMtechniquestogeneratephysicalmodelsfromCASorCADdata.Thisisdonetotransfertheshapesfromthevirtualworldtothephysicalworld.†TofillthegapbetweenamanuallyoptimizedphysicalmodelandtherequiredCADsurfacedescriptionaspecialtaskisnecessaryThesurfacereconstructionorreverseengineeringofshapesInthefieldofstandardengineeringdesigntherearetheCADdesignersorCADengineers,whoareworkingwith3Dsystems.Accordingtotheirtasks,workingfieldsandthelevelofCADapplicationtheyareusingwireframetechniques,surfacesystemsand/orsolidmodelling.Now,withintroductionofmoresophisticateddesigntechniquesandwiththeincreasinginformation,whichisstoredinaCADmodel,manyfieldsofCADapplicationsandrelatedspecialjobprofilescanbedistinguished†Componentdesigners.Theyareinchargeofthedesignofspecialcomponentsoftheproduct.†EngineersforParametricAssociativeDesign†CADdesignersfortoolsandqualityaids.†Processplaners†Manufacturingsimulators†CAplantlayoutersParalleltotheCADdesignthesimulationofproductpropertiesisanotherimportanttaskintheproductdevelopment,whichgivesanotherjobprofile†Engineersforsimulation,analysisandcalculation.Togeneratereliableresultstheyusuallyarehighlyspecializedoncertaintasks.Consequentlythisjobprofilecouldbefurtherstructured.Informertimestheseengineersforsimulationoftenworkedinisolateddepartments,startingtheanalysiswhenthedesignhadbeenpreliminarilyfinished.Nowadaysthesetasksarecompletelyintegratedinthedesigndepartmentandgoalongwiththedesign.AtthemomentthereisatendencythattheengineersperformapreliminaryanalysiswithintheirCAxsystemtoevaluatetheirdesign.ThislistofpeopleandtasksinvolvedinCAxcanbecontinued,allofthemneedatleastsomeCAxknowledge†SpecialistsforCAxgraphicsgeneration†ClerkswithinthepurchasingdepartmentsforarrangingcontractsbetweenOEMandthesubcontractorsC.W.Dankwortetal./ComputerAidedDesign3620041439–14501441andsuppliers.†SWdesignandSWimplementation†ApplicationSWdefinition†CAxsystemsinoperation†CAxsystemtestingandSWqualitycontrol†Computercentreandnetworkoperation†Informationmanagement†CAxdataexchangedevelopmentandoperationofSWtoolsTheseexamplesshowthatthereisavarietyofdifferentjobs,eachneedingdifferentknowhowinthedifferentfields.SomeexamplesaregiveninFig.2.Industrialexpertsestimated,thatforoneCADworkstationabout10otherworkstationsareusedinsubsequentactivitieslikeviewingetc.3.5.TheHumanFactorandtheenvironmentThedifferentknowledge,whichisneededfororwhichisgainedinthedifferentjobs,isoneaspect.AnotherveryimportantaspectintrainingpeoplefortheirCAxjobisthehumanfactor.Therearethreepointswhichhavetobeconsidered†Thepast,theeducationandtheexperienceofaperson†Thehumanpotential,theabilitytofulfilthetasksofmodernproductdevelopmentwithCAxandInformationManagementtools.†Theenvironmentinwhichapersonhasworkedbeforeandinwhichitisgoingtoworknext.Eachofthepointsabovewillbebrieflydescribedinthefollowing,alreadyshowingthecomplexityofmodernCAxeducationandthatthereisnothinglikeastandardizedCADeducation.5.1.Thepast,theeducationandtheexperienceofapersonEachpersonhasadifferentbackgroundand,ashis/hermindisstronglyinfluencedbyit,thewayofthinkingandlearningwillbedifferentfrompersontoperson.AnexampleInformertimesitwasastrenuoustasktomakedesigners,whohadworkedmanyyearsatdraftingtables,useaCADsystemefficiently.Forthemthismeanttoapproachproblemsinacompletelynewway.Buttheexperience,whichwasgainedbysolvingproblemstheclassicalway,oftengotlost.Itcouldnotbetransferredtoyoungengineers,whostartedtheircareeronCADsystems.ThisexampleshowsoneofthedutiesofCAxeducationToteachalsosomedesignmethodsusedinformerpreCADtimetomakeusersawareofdifferentwaysofthinkingandofapproachingproblemsinordertoavoidriskslikeTherestrictionofthethinkingtothelimitsgivenbythecapabilityoftheITtoolinuse.5.2.ThehumanpotentialThissecondaspectismoresensitivethanthefirstone.Itisfact,thatnotallpeoplehavethesamecreativity,efficiencyandflexibility.Muchresearchhasbeendoneonthismatter,butitwillgofarbeyondthescopeofthispapertogointodetailshere.Therelationbetweennumberofpeopleononesideandskill,potentialontheothersideisoftensimilartotheclassicalGaussiandistributionseeFig.34.Peopleofhighcapabilityandefficiencyshouldberelatedtotherighthandsideofsuchadistribution.TrainingthemonaCAsystemwilltakeveryshorttimeandsuchstudentsoremployeeswillworkwithhighproductivityinaveryshorttime.Thesearetypicalpilotuser,whichareofhighestimportanceforthebreakthroughofCAxtechnologyincompanies.Mostoftheengineersmaybeconsideredtobeontheaverage.Currentgrouptrainingmethodsusuallyfocusonthismajority.Theeffectwillbe,thatsomepeopleinthislargegroupareswampedbythespeedandcontentofthetraining,whileothersareunchallengedbyit.Thepraxisinindustryshowsthatthedemandsonengineersforthemodernparametricassociativedesignoftencannotbefulfilledafterstandardtraining.ButtherearealsopeoplerelatedtotheleftsideoftheGaussiandistribution,whoneedmoreeffortsintrainingtobecomeaCAxengineerthentheaverage.Nostandardprocedurecanbeproposedhere.ButitFig.3.TheGaussiandistribution.Fig.2.PortfoliooftheCAlandscapeinanenterprise.C.W.Dankwortetal./ComputerAidedDesign3620041439–14501442