外文翻译--计算机辅助生产和控制系统.doc

ComputerinManufacturing1.1Computer-aidedProductionandControlSystems(CAPACS)Manufacturingtechnologyhasbeenaroundformanyyears.Overtheseyears,ithasgonethroughmanychanges,rangingfromthesimpletothecomplex.Thedrivingforcesbehindthechangeswerepeoplesdesirestoimprovebasicneedssuchasfood,clothing,shelter,andrecreation.Tomeetthesedesires,methodshavebeendevelopedfromproducingsimpledevicessuchasweaponsforobtainingfoodtotodaysmodernmanufacturingsystems,whichusecomputerstoproducesuchitemsastelevisionsandspacevehicles.Computersarebeinggivenanincreasinglyimportantroleinmanufacturingsystems.Acomputersabilitytoreceiveandhandlelargeamountsofdata,coupledwiththeirfastprocessingtime,makesasystemapproachindispensable.Theuseofcomputersinmanufacturingisnowcomingofage.Computerapplicationinmanufacturingproductioncontrolsthephysicalprocessandistypicallyreferredtoascomputer-aidedmanufacturing(CAM).ItisbuiltonthefoundationofsuchsystemasNC,AC,robotics,automatedguidedvehiclesystem(AGVS),automatedstorage/retrievalsystem(AS/RS),andflexiblemanufacturingsystem(FMS).Someofthenewusesarebrieflydiscussedbelow.Moredetaileddiscussionsarepresentedinsubsequentchapters.Manyinterrelatedmanufacturingactivitiesaregroupedtogethertoformaspecialapplicationsystemthatmaybereferredtoasaproductionandcontrolsystem(PACS).ThegroupingofmanufacturingactivitiesintoPACSvariesfromonemanufacturingenvironmenttoanother.APACSisdefinedasasubsysteminaglobalmanufacturingenvironment.Itmaybeasinglesubsystem,oritmaybeacomplexsetofsubsystems.AnillustrationofPACSworkinginaglobalmanufacturingsystemisshowninFig.1.1.ForPACStomeettheirdesignedfunctionalrequirements,theyshouldbedesignedtofunctionindependentlyofotherPACS.Also,PACSshouldbetoworkcollectivelywithotherPACSinatotalintegratedmanufacturingenvironment.EachPACSinthetotalFig.1.1InteractionofPACSinaManufacturingSystemsystemcanhaveaneffectontheotherPACSinthetotalsystem,andasystemsplanningapproachmustbetakenforthefollowingreasons:TopreventduplicationofeffortToenablevitalinformationtopassefficientlythroughthesystemToalloweachPACStoknowitsrelationtotheothersandhowitaffectstheothersTomakethewholemanufacturingsystemfunctionmoreefficientlyandproductivelyComputerarebyfarthemostpowerfulsingleapproachusedinintegratingandmanipulatingtheseriesofinterrelatedmanufacturingPACSandactivities.Theyhavebroughtmanufacturingtechnologyintotheeraof“smart”machines.Theadvancesintechnicalproductionhavebroughtaboutacomputertechnologyandmanufacturingtechnologythathasenhancedmanufacturingtechnologydevelopment.Thismarriageisthebasisforcomputer-aidedproductionandcontrolsystems(CAPACS),whicharecomputer-drivenCAPACS.Thus,CAPACShaveincreasedtherolesofsmartmachinesinproductionandcontrolfunction.Theincreasedrolesofsmartmachineshavedemandedamoreintimatecommunicationandinteractionbetweensuchfunctionsasdesign,financialaccounting,production,personnel,andmarketing.Thewaysinwhichproductionoperationsareconceptualized,formalized,discharged,andperformedarebeingchangedbyCAPACS.TypicalCAPACSinmanufacturingareasfollows:CADComputer-aideddesignCAINComputer-aidedinspectionCAMComputer-aidedmanufacturingCAPPComputer-aidedprocessplanningCAQCComputer-aidedqualitycontrolCIPMComputer-integratedproductionmanagementDNCDirectnumericalcontrolGTGrouptechnologyFig.1.2givesanoverviewofinterrelatedfunctionsofCAPACSworkingfromanintegrateddatabasesystem.Thedesigndata,generatedbytheinteractionbetweenCAPACS,areasinglecollectionofalltheinformationthatdescribestheproductandrelatedoperations.Itisthehubofthemanufacturingwheel.TheCADsystemistheprincipaltoolusedbyengineeringincarryingoutitsresponsibility.Fig.1.2InteractionofCAPACSinamanufacturingSystemThespokesofthewheelaremadefromvariouskindsifCAPACSinvolvedintheactivity.EachCAPACShasacommunicationlinktothecontrolleddatabasesothatitwillcapturethedatatoformitsowndistributeddatabase.Valuesareaddedthedistributeddatabasetomeettheneedsandrequirementsofitsexpectedusers.TheapplicationofCAPACStothemanufacturingprocessenablesthetotalsystemtoincreaseproductivity,reducewaste,andpr