生产自动化毕业论文中英文资料外文翻译文献

自业中英料翻译资CharlesL.D.ControlHall,Inc..2000Abstract:Automationawidelyterminmanufacturing.Inthiscontext,automationdefinedasatechnologyconcernedtheapplicationmechanical,andsystemstooperateandcontrolproduction.Examplesofthistechnologyinclude:AutomaticmachinetoolstoprocessAutomatedlinesandsimilarsequentialproductionsystems.Automaticassemblymachines.IndustrialAutomaticmaterialhandlingandstoragesystems.•Automatedinspectionsystemsforqualitycontrol.Feedbackcontrolcomputerprocesscontrol.Computersystemsproceduresforplanning,collection,anddecisionmakingtosupportmanufacturingactivities.Keywords:Automationmechanicalcomputer1Automatedproductionsystemsclassifiedcategories:automationandautomation.FixedAutomationFixedHarderwastowhenthewordautomation.Fixedautomationreferstoproductionsystemsinwhichtheofprocessingassemblyisfixedbytheconfigurationandcannotbereadilychangedwithoutalteringtheequipment.eachoperationinthesequenceisusuallysimple,theintegrationandcoordinationmanyoperationsasinglesystemmakesfixedautomationTypicaloffixedautomationinclude1.highinitialinvestmentforcustom-engineeredequipment,highproduction3.applicationproductsinwhichhigharetobeproduced,4.relativeinflexibilityaccommodatingchanges.Fixedautomationiseconomicallyjustifiableforproductswithhighdemandrates.Thehighinitialinvestmentintheequipmentcanbedividedoveralargenumberofunits,perhapsmillions,thusunitcostcomparedalternativemethodsofproduction.Examplesoffixedautomationincludetransferlinesformachining,dialindexingmachines,andautomatedassemblymachines.Muchofthetechnologyinfixedautomationwasdevelopedtheautomobiletheline(datingtoaboutisanexample.ProgrammableAutomationForprogrammableautomation,theequipmentisdesignedsuchawaythatsequenceofproductionisbyae.,ofandinterpretedthesystem.theoperationcanbereadilychangedpermitdifferentconfigurationsbeproducedonthesameequipment.Someofthefeaturesthatcharacterizeautomation1.highinvestmentingeneral-purposeequipment,2.lowerratesthanautomation,flexibilitydealwithchangesinproductconfiguration,and4.suitedlowand/mediumproductionsimilarorpartsg.partfamilies).Examplesofprogrammableautomationincludenumericallycontrolledtools,industrialrobots,and2logiccontrollers.Programmablesystemsareusedtoproducepartsorproductsbatches.TheyareappropriatewhenrepeatordersbatchesoftheproductareToproduceeachofaproduct,thesystemmustbeprogrammedwiththesetofmachineinstructionsthatcorrespondtothatproduct.Thephysicaloftheequipmentmustalsobechanged;specialfixturesmustbeattachedtothemachine,andtheappropriatemustbeloaded.changeovercanbetime-consuming.aresult,usualproductionforagivenbatchincludes1.a(3periodduringwhichtheandreprogrammingaccomplished2.aperiodwhichthebatchisprocessed.Thesetup-reprogrammingperiodconstitutesnonproductiveoftheautomatedTheeconomicsofprogrammableautomationrequirethatthesetup-reprogrammingincreases,productionsizemustbemadesoastospreadcostoflosttimeoveranumberofunits.Conversely,ifsetupandreprogrammingcanbereducedzero,thebatchsizecanbereducedtoone.Thisisthetheoreticalbasisforflexibleautomation,extensionprogrammableAflexibleautomatedsystemonethatiscapableofavarietyofproducts(orwithminimaltimeforchangeoversoneproducttoThetimetoreprogramthesystemandthephysicalisminimalresultsinvirtuallylostproductiontime.Consequently,systemiscapableproducingvariouscombinationsschedulesofproductsincontinuousflow,ratherbatchproductioninterruptionsbatches.Thefeaturesofflexibleautomationare1.highinvestmentforacustom-engineeredsystem,2.continuousproductionmixturesofproducts,abilitytochangeproductmixtoaccommodatechangesindemandratesforthedifferentproductsmade,mediumproductionand5-flexibilitytodealwithproductdesignvariations.Flexibleautomatedproductionsystemsinbyoneormorethefollowing1.usingpartconcepts,bywhichthemadeonthesystemlimitedinvariety;2.reprogrammingtheinand/or3sothatreprogrammingdoesnotinterruptproduction;3.downloadingexistingthesystemproducepreviouslymadepartswhichprogramsalreadyprepared;)usingquick-changesothatphysicaltimeisminimized;5.thathavebeendesignedforanumberofpartand6.equippingsystemwithlargenumberofquick-changetoolsthatincludethevarietyofprocessingneededtoproducethepartfamily.theseapproachesbesuccessful,variationinthestylesproducedonaflexibleautomatedsystemisusually)morelimitedabatch-typeautomationsystem.Examplesofflexiblearetheflexiblemanufacturingsystemsforoperationsthatdatebackthelate1960s.AutomationStrategiesAnumberoffundamentalstrategiesexistforimprovingproductivityinmanufacturingThesestrategiesofteninvolvetheuseofautomationtechnologyandare,therefore,calledautomationstrategies.Indicatinglikelyeffectseachstrategyonoperatingfactorssuchascycletime,nonproductivetime,leadtime,andotherproductionparameters.NumericalcontrolNumericalcontrol(oftenabbreviatedcanbedefinedaformofprogrammableinwhichtheiscontrolledbynumbers,andsymbols.InNC,numbersaofinstructionsforaparticularorjob.Whenthejobchanges,programofinstructionsischanged.ThiscapabilitychangetheforeachnewiswhatgivesNCitsflexibility.Itismucheasierwritenewthantomakemajorchangesintheproductionequipment.NCequipmentusedinareasofmetalpartsfabricationandcomprises15%themoderninindustrytoday.Sincenumericallycontrolledmachinesconsiderablymoreexpensivetheirconventionalcounterparts,theassetvalueofindustrialmachinetoolsproportionallymuchlargerthantheirEquipmentnumericalcontrolhasbeen4designedperformdiverseoperationsasmilling,turning,grinding,metalpressspotwelding,arcwelding,riveting,assembly,drafting,inspection,andpartshandling.Andisbynomeanscompletelist.Numericalcontrolshouldconsideredapossiblemodeofoperationforproductionpossessingfollowingcharacteristics:Similarworkpartstermsofraw(e.g.,stockformachining).Theworkpartsproducedinsizesand3.Theworkpartsareproducedinbatchesofsmalltomedium-sized4.Asequenceofsimilarprocessingstepsisrequiredcompletetheoneachworkpiece.Manymachiningjobsmeettheseconditions.Themachinedworkpartsaretheyspecifiedinmanydifferentsizesandshapes,mostmachinedpartsinindustrytodaymadeinsmallmedium-sizesizes.Toproducepart,asequenceofdrillingmayberequired,oraseriesofturningormillingoperations.ThesuitabilityofNCforkindsofisthereasontremendousgrowthnumericalcontrolinmetalworkingoverthelastyears.BasicComponentsanNCSystemAnoperationalnumericalcontrolsystemconsistsofthefollowingthreecomponents:Programofinstructions.Controlleralsocalledmachinecontrolunit(MCU).3.MachineorothercontrolledTgramofinstructionsastheinputthecontrollerwhichinturncommands)machinetoolotherprocessbecontrolled.PrograminstructionsTheprogramofinstructionsthedetailedstep-by-stepsetofdirectionstelltheWmmachinetoolwhattodo.ItiscodedinnumericalsymbolicformonsometypeofinputmediumthatcanbeinterpretedthecontrollerThemostinputmediumi-inch-widetape.Overyears,other5formsofinputmediahave(beenincludingpunchedcards,magnetictape,even35-mmmotionpicturefilm.TherearetwomethodsofinputtotheNCsystemwhichshouldbeTheisbymanualofinstructionaldatatothecontrollerunit.Thisisandisusedexceptanauxiliaryofcontrolorwhenoneoraverylimitedofpartsaretobemade.secondofofaacomputer.ThisisdirectnumericalorDNC.Tgrammer'sjobistoprovideasetofdetailedinstructionsbywhichsequenceofprocessingistobeperformed.Foramachiningoperation,theprocessingsteps4involverelativemovementthemachinetableandthecuttingControllerThesecondcomponentoftheNCsystemiscontrollerunit.Thisconsistsofelectronicsthatreadandinterprettheprogramofinstructionsandconvertitintomechanicalofthetool.Thetypicalofthecontrollerincludethetapereader,adatabuffer,signaloutputchannelsthemachinefeedbackfromthemachinetool,andthecontrolscoordinatetheoveralloperationoftheelements.Theiselectrical-mechanicaldeviceforandreadingthepunchedtapecontainingtheprogramofinstructions.Thedatatapearereadthedatabuffer.Thepurposeofthisdeviceistostoretheinputinstructionsinlogicalblocksofinformation.AblockofinformationrepresentscompletestepthesequenceofprocessingForexample,blockmaybethedatarequiredtomachinecertainaholeatthatThesignalchannelsaretotheandothercontrolsthemachineThroughchannels,theinstructionsaretothetoolfromtheunit.Tomakethattheinstructionsbeenproperlyexecutedbythemachine,feedbackdataaresentbacktothe6controllerviathefeedbackchannels.Themostimportantofthisreturnistoassurethattableandworkpart$beenproperlyrespecttotool.Mostmachinetoolsinuseareprovidedpositionfeedbackforthispurposeandarereferredtoasclosed-loopsystems.However,inrecentyearstherebeenagrowththeuseopen-loopsystems,donotmakeoffeedbacktothecontrolleradvocatesoftheopen-loopclaimthatthereliabilitythesystemisgreatenoughfeedbackcontrolsareneededandanunnecessarycost.Sequencecontrolscoordinatetheactivitiesoftheotherelementsoftheunit.Thetapereaderisactuatedreaddataintobufferfromtape,signalssenttoandfromthemachineandsoon.typesofoperationsbeistheofthesequencecontrols.AnothertheNCsystem,bephysicallypartofthecontrollerorpartofmachinetool,isthecontrolpanel.ThecontrolpanelorcontrolconsoletheswitchesbythemachinerunstheNCsystem.Itmayalsocontaindisplaystoprovideinformationtotheoperator.AlthoughNCsystemisansystem,theoperatorisstillneededturnthemachineandoff,tochangetools(someNChaveautomatictoolchangers),loadunloadthemachine,toperformotherduties.beabletodischargethesethemustbeablecontrolthesystem,andisdonethroughcontrolMachineThethirdbasicNCsystemisthemachineorothercontrolledprocess.Itisthepartofthesystemperformsusefulwork.InthemostexampleofanNCsystem,onedesignedtoperformmachiningoperations,thetoolconsistsoftheandspindleaswellasthemotorscontrolsnecessarydrivethem.alsoincludescuttingtools,workfixtures,otherauxiliaryequipmentinthemachiningoperation.7TransferMachinesThehighestdegreeofautomationobtainablewithspecial-purpose,multifunctionmachinesisachievedbyusingtransfermachines.Transfermachinesareessentiallyacombinationindividualarrangedtherequiredsequence,connectedworkdevices,andintegratedinterlockedWorkpiecesaretransferredbetweenwhichwithhorizontal,orangularunitstoperformmachining,gagging,workpiecerepositioning,assembling,washing,orotheroperations.Thetwomajorclassestransfermachinesrotaryandin-linetypes.Animportantadvantageoftransfermachinesisthattheypermitthemaximumnumberofoperationstobeperformedsimultaneously.isrelativelynolimitation(thenumberofworkpieceorplanesthatcanbesincedevicescanbeinterposedintransfermachinesatpracticallyanyforinverting,ororientingworkpiece,astocompletethemachiningoperations.Workrepositioningalsominimizestheneedforangularmachiningheadsandallowsoperationsbeperformedinoptimumtime.Completefromroughcastingsorforgingstofinishedpartsisoftenpossible.Onepartsareproducedonawitheachindexofthetransfersystemthatmovespartsfromstationtostation.Productionefficienciesofsuchmachinesgenerallyrangefrom50%amachineavarietydifferentpartsto85%foramachineproducingpart,inhighproduction,upontheworkpiecehowtheisoperated(materialshandlingmethod,maintenanceprocedures,etc.)Alltypesmachiningsuchasdrilling,tapping,reaming,boring,andmilling,areeconomicallycombinedontransfermachines.Lathe-typeoperationssuchasturningandfacingarealsobeingperformedontransfermachine,theworkpiecesbeingrotatedinselectedmachiningstations.Turningoperationsperformedlathe-typeinwhichmultipletoolarefedonslidesontunnel-typebridgeunits.Workpiecesarelocatedcentersandby8chucksateachstation.Turningwithareavailableuseonmachines.CNCunitsthemachinetobealteredtochangesworkpiecedesignandcanalsobeusedforautomatictooladjustments.Maximumproductioneconomyontransferlinesisoftenachievedbyassemblingpartstotheworkpiecesduringtheirmovementthroughmachine.Suchasbushings,Welchplugs,heattubesbeassembledthenmachinedortestedduringtransfersequence.nuttorturingfollowingapplicationpartsubassembliesalsobecarriedGundrillingorreamingontransfermachinesisanidealapplicationprovidedthatpropermachiningemployedgoodbushingareContourandturningofsphericalandothersurfacescanbedonewithtracercontrolledinserts,eliminatingneedforcostlyspecialtools.In-processofreamedboredholessettingaredoneontransfermachinestomaintainclosetolerances.Lesssometimesperformedonmachinesincludegrinding,inductionofringgearsshrink-fitonflywheels,hardeningvalveseats,deeprollingapplycompressivepreloads,burnishing.Transfermachineshavelongbeenusedintheautomotiveindustryforidenticalcomponentsathighproductionrateswithminimumofmanualparthandling.Inadditiondecreasingrequirements,suchmachinesensureuniformhigh-qualityatlowerTheyarenolongerconfinedmachiningnoweliminateforsubsequentsuchgrindingandMorerecently,therehasbeenanincreasingdemandfortransfermachineshandlelowervolumesofsimilarevendifferentsmallersizes,withforquickbetweenproductionBuilt-inflexibility,abilitytorearrangeandmachiningunits,theprovisionofidleanymachine,featuresarefeasiblewhenredesigns9common.Manysuchmachinesnowbeinginnoautomotiveapplicationslowerproductionrequirements.SpecialfeaturesavailabletoreducepartchangeoverincludeIstandardizeddimensions,modularconstruction,fixturesmountedonmasterpalletsthatremainthemachine,interchangeablefixturecomponents,theabilitytolockcertainstationsdifferentpartsbymeansofselectorswitches,programmablecontrollers.Productdesignisalsoimportantandtransferandclampingsurfacesshouldbeprovideddifferentpartspossible.ProgrammableLogicControllersAprogrammablelogic(PLC)isausedtocontrolmachinemotionorprocessoperationbymeansofaThesignalsandreceivesinputsignalsinput/outputdevices.APLCoutputsinstimuliatinputstologicprescribedbythestoredprogram.inputsmadeupoflimitswitches,pushbuttons,thumbwheelspulses,analogsignals,ASCIIserialdata,andorBCDfromabsolutepositionencoders.outputsarevoltagecurrentlevelsdriveenddevicessuchassolenoids,motorstarters,relays,lights,andsoon.Otheroutputdevicesincludedevices,digitalBCDdisplays,ASCIIcompatibledevices,servovariable-speedandevenProgrammablecontrollerswere(circain1968)GeneralMotorsCorp,andotherautomobilemanufacturerswereexperimentingtoseeifbetoscrappingalltheirhardwiredcontrolpanelsofmachinetoolsandproductionequipmentduringamodelchangeover.Thisannualtraditionwasbecauserewiringofthepanelsmoreexpensivethannewones.Theautomotivecompaniesapproachedanumberofcontrolequipmentandaskedthemdevelopcontrolthatwouldalongerproductivelifewithoutrewiring,butwouldstillbeunderstandabletoandrepairablebyplantpersonnel.Thenewproduct"programmablecontroller".TheprocessorofthePLCcontainscentralprocessing10unitandmemory.Thecentralprocessingunit(CPU)thedirector"oftheprocessor,thememorystoresinformation.Comingintotheprocessoraretheelectricalsignalsfromtheinputdevices,asconditionedtheinputtovoltageacceptableprocessorTheprocessorthestateofIandoutputsbasedoninstructionsstoredinthememoryofthePLC.example,themaybeprogrammedthatifaninputconnectedtoalimitswitchistrue(limitswitchclosed),thenacorrespondingoutputtoanmoduleistobeenergized.outputmightasolenoid,example.Theprocessorthiscommandthroughitsmemorycomparesoneachscantoseeifthatswitchinfact,closed.IfitistheprocessorenergizesthesolenoidturningonoutputTheoutputsuchasaormotorstarter,iswiredtoanoutputmodule'sterminal,itreceivesshiftsignalfromprocessor,effect,theprocessorisperformingalongcomplicatedseriesofdecisions.Theperformssuchdecisionssequentiallyandinaccordancethestoredprogram.Similarly,I/Oallowsprocessortomakedecisionsbasedonthemagnitudeofasignal,ratherthanjustitisonoroff.Forexample,processorbeprogrammedtoincreaseordecreasesteamflowaboiler(analogoutput)basedonacomparisonoftheactualtemperatureintheboiler{analoginput)thedesiredtemperature.Thisisoftenperformedbycapabilitiestheprocessor.BecauseaPLCis"softwarebased",itslogicfunctionscanbechangedreprogrammingmemory.Keyboardprogrammingdevicesfacilitateoftherevisedwhichcanbedesignedtocauseanexistingmachineorprocesstooperateadifferentsequenceortorespondtodifferentlevelsof,orcombinationsstimuli.Hardwaremodificationsareneededonlyifadditional,orrelocated/outputdevicesinvolved.11翻自摘要：自动化是一在制造业中广泛使用的术语。文中，自动化可定义为有关应用机、电子和计算机的系统去管理和控制生产的技这种技术的例子包括．加工零件自动化机床．自动连续产线和类似的顺序生产系统。．自动装配器。．工业机器．自动材料理和储存系统．用于质量制的自动检验系统。．反馈控制计算机程序控制．使支持制业活动的计划、数据收集和决策的过程自动化计算机系统。关键字：自动化制造机械自动检计算机自动化生系统可被化分为两个基类别硬件自动化和可编程自动化。12硬性自动硬性自动化哈德尔（杜撰“自动”这个单词时所提出的硬性自动是指生产系统中生产顺序或装配工作由设备配确定，并且在没更换备的情况下不能轻易改变。虽然顺序中的每一操作通常是简单的，是，将许多简单的操作集成和协调成一个单一统使硬性自动化变得杂化。硬性自动化的典型特点包括：1定做设计设备的光期投资高2高生产效率3应用于批量产品生产，和适应产品变的相对固定。硬性自动化高需求率产品是经济合适的。先期设备的高投可以被大量部件摊，也许是数百万件，这样与其他生产方法相部件花费低。硬性自化的例子包括机加工连续生产线、转盘换位机和自动装配机器。硬自动化的大部分技术是在汽车工业中发展起来；连续生产线（追溯大约1920年）就是个例子。可编程自化对于可编程动化，以由程序，即一套可以被系统识别和解的编码指令来控生产操作工序的方式来设计设备。这样就可毫困难地改变操作顺序允许在同一设备上生产不同的产品结构。表现编程自动化的一些特包括1通用编程设备的高投人比硬性自动化更低的生产率，付产品结构变化的柔性，和4适合于类似产品或零件的小和／或中等量的生产（例如，零件族程自动化的例子包括数控机床、工业器人和可编程逻辑控制器。可编程生产统经常用于成批的生产零件或产品。它们尤其合于相同产品成的重复订单为了生产一批新产品，必须为系统制与新产品相适应的套机器指令。设备的实际装备也必须改变，必给机器附加特殊的夹，必须装上适当的刀具。这种转换过程可能是时的。结果，一批特产品的一般生产周期包括1完准备和重编程的阶段2该批产品的工阶段。设置--重编程阶段构成了自动化系的非生产时间。可编程自动的经济性要求：随着设置一重编程时间增长，产批量的大小必被编得较大以便在众多设备中分散损失的生产间的消耗。相反，果设置和重编程时间能降到零,则批量的大小可降至一个。这是柔性自化的理论基础，即可编程自动化的延伸。柔性动化系统是从一个产转产到另一个产品时，时间损失最少的能生产多种类产品（或零件的系统、系统重编程和改变实际装备的时间是少的，并且事实上导无生产时间损失。因此，系统能在连续流程中产不同的产品组合和程，而不是批处理间有中断的批处理生产。柔自动化的特点包括：1.用工程定制系统的高投2连续的产品混合生产，3.改变产品混合适应对所生产的不同产品的需求率变化的能力中等生13产率，和5.处产品设计变更具有柔性。柔性自动化产系统通过下面一个或更多的途径应用于实践：1.使用零件族念，根据此概念系统中制造的零件在种类上有限制；预先，并且或离线对系统再编程以便再编程不会中断生产3.下载已有程序到系中来生产以前制造过的零件，为这些零件已编过程序；4.使用快速卸的夹具以便最大限度地缩短实际装备时问5便用为有限零件类型设计的夹具族；和给系统装配大的快速装卸刀具，们包括用来产零件族的各式各样的加工操作工具了实现这些应用在柔性自动生产系统上生产的零件类型的变化通常比批处类型的可编程自动化统要局限的多柔性自动化系统的例子可追溯到20纪60年代晚期的行机加工操作的柔性制造系统。自动化策有许多基本略用来提高生产操作中的生产率。这些策略通包括自动化技术使用。因此，叫做自动化策略。数字控制数字控制（缩写为数控）可定义为一种可编程自动化的形，其中工艺是由数、字母和符号来控制的。在数控中，数字构成为某特定工件或任务计的指令程序。当任务变更时，指令程序也相改变，改变每种新任程序的能力使数控具有柔性。编写新程序比改主要生产设备要容易多。数控设备用所有的金属零件制造领域，在当今工业的现代床中大约占15%。因为数控机床比传统机昂贵得多，业数控机床的资产价值比起他的所占比位来要大得多。应作数控的设备已被来完成各式各样的操，如钻削、铣削、车削、磨削、饭金压制、点、弧焊、铆接、装配制图、检验及零件处理等。这绝不是一个完全列举。应把数字控制成一种加工控制的可行方法，用于具有下列特的任何生产情况：．用原材料工类似工件（如用于机加工的金属材料．零件被生成各种尺寸和形状。．以小到中规模批量生产工件。．完成每个件的加工要求一系列的相似加工步骤。许多机加工件满足这些条件。这些机加零件是金属的，给们规定了不同的寸和形状，而且当今工业生产的大部分机加零被制成小到中等规模多种尺寸。为了生产每一个零件，需要一系列钻削操作或一系列的削或铣削操作。数字控制对这些零件的适应性数字控制在过去25年中在金属制造业中巨大增长原因。数字控制统的基部件一个可操作数字控制系统由下列三个基本部件组成：14指令程序。控制器单元也称为机床控制单元。机床或其他控工艺。指令程序指令程序是诉机床如何去工作的一套详尽的一步步的指令。它被以数字或号的形式编码在一些可以被控制器单元翻译的人介质上。最常用输入介质是1寸宽的穿孔在这些年中，也使用了其他形式的输人质，包括穿孔卡片、磁带、甚至35mm电影胶。还有其他两向数字控制系统进行输人的方法必须提及。第种是用手工将指数据输入到控制器单元。这是费时的，除非作辅助控制手段或只制一个或非常有限数目的零件时，一般很少使用第二种输入方法是与算机直接相连。这叫做直接数字控制或DNC。指令程序是被称为部件工作程序员的人编写的。程序员的作是提供一套详的指令，通过这些指令可完成一系列加工步骤一个机加工操作，加步骤包括机床台面和刀具的相对运动。控制器单数控的第二基本元件是控制器单元。这由可以阅读和翻译令程序并把它转成机床机械运动的电子设备和硬件组成。控制单元的典型元件包括带阅读机、数据缓冲器、通向机床的信号输出道、来自机床的反馈道、以及协调上述元件整体操作的顺序控制器磁带阅读机一个用于缠绕和阅读含有指令程序的穿孔磁带机电装置。磁带含有的数据被读入数据缓冲器。该设备的目的将输人指令储存在信逻辑单元。一个信息组通常代表加工元件顺序的一个完整步骤。例：一个信息组可以是移动机床台面到特定位置在该位置钻孔所需的据。信号输出通与机床的伺服马达和其他控制器相连过这些通道，指令由控制单元送到机床。为了弄清楚指令是否己被机床确执行，反馈数据通反馈通道回到控制器。反馈回路的重要功能是保台面和工件已经相于刀具正确定位。为此当今使用的大多数数控床具有位置反馈控制，并被称为“闭环系统，近些年开环系统的使用可靠性足够高因此反馈控制器是不需要的，是一笔不必要的外花销。顺序控制器调控制器单元其他元件的动作。磁带阅读机执将数据从磁带读入缓器中，来回向机床传送信号等等。这些类型的作必须是同步的，这是同步控制器的功用。数控系统的一个元件是控制面板，它实际上可能是控制器元或机床的一部。控制面板或控制台山刻度盘和开关组成，机操作者通过他们运转控系统。控制面板也可有数据显示器为操作者供信息。虽然数控系是一个自动化系统，但仍需要人类操作者来开机床，更15换刀（一些数系统有自动化刀具更换装置床加载和卸载以及完成其他各各样的任务。为了履