数控系统 外文翻译 外文文献 英文文献

数控系统外文翻译外文文献英文文献_文档视界NumericalControlSystem

Thenumericalcontrolsystemisthedigitalcontrolsystemabbreviation.Byearlyiscomposedofhardwarecircuitiscalledhardwarenumericalcontrol(HardNC),after1970,hardwarecircuitcomponentsgraduallyinsteadbythecomputercalledforcomputernumericalcontrolsystem.

Computerizednumericalcontrolsystemisasystemthatisusecomputercontrolprocessingfunctiontoachievenumericalcontrolsystem.CNCsystemaccordingtothecomputermemorystoredinthecontrolprogramexecutionpartorall,numericalcontrolfunction,andisequippedwithinterfacecircuitandservodrivethespecialcomputersystem.

CNCsystemconsistsofNCprogram,inputdevices;outputdevices,computernumericalcontrolequipment(CNCequipment),programmablelogiccontrollers(PLC),thespindleandfeeddrive(servo)drive(includingdetectiondevices)andsoon.

ThecoreofCNCsystemisequipment.ByusingthecomputersystemwiththefunctionofsoftwareandPLCinsteadofthetraditionalmachineelectricdevicetomakethesystemlogiccontrolmorecompact,itsflexibilityandversatility,reliabilitybecomemorebetter,easytoimplementcomplexnumericalcontrolfunction,useandmaintenancecanbemoreconvenient,anditalsohasconnectedandsuperordinationmachineandtheremotecommunicationfunction.

Atpresent,thenumericalcontrolsystemhasvarietyofdifferentforms;compositionstructurehasitsowncharacteristics.Thesestructuralfeaturesfromthebasicrequirementsoftheinitialsystemdesignandengineeringdesignideas.Forexample,thecontrolsystemofpointandcontinuouspathcontrolsystemshavedifferentrequirements.FortheTsystemandtheMsystem,therearealsoverydifferent,theformerappliestorotarypartprocessing,thelattersuitableforspecial-shapedtheaxiallysymmetricalpartsprocessing.Fordifferentmanufacturers,basedonhistoricaldevelopmentfactorsandvarytheircomplexfactors,mayalsobethinkinginthedesignisdifferent.Forexample,theUnitedStatesDynapathsystemusesasmallplateforeasyreplacementandflexiblecombinationoftheboard;whileJapanFANUCsystemisalargeplatestructuretendstomakethesystemworkinfavorofreliability,makethesystemMTBFratecontinuestoincrease.However,nomatterwhatkindofsystem,theirbasicprincipleandstructureareverysimilar.

Thenumericalcontrolsystemgenerallyconsistsofthreemajorcomponents,namelythecontrolsystem,servosystemandpositionmeasuringsystem.Controlproceduresbyinterpolationoperationworkpiece,issuecontrolinstructionstotheservodrivesystem;servodrivesystemcontrolinstructionsamplifiedbytheservomotor-drivenmechanicalmovementrequired;measurementsystemdetectsthemovementofmechanicalpositionorspeed,andfeedbacktothecontrolsystem,tomodifythecontrolinstructions.Thesethreepartscombinetoformacompleteclosed-loopcontroloftheCNCsystem.

Controlsystemmainlyconsistsofbus,CPU,powersupply,memory,operatingpanelanddisplay,positioncontrolunit,programmablelogiccontrollercontrolunitanddata

input/outputinterfaceandsoon.ThelatestgenerationofCNCsystemalsoincludesacommunicationunit;itcancompletetheCNC,PLC'sinternaldatacommunicationsandexternalhigh-ordernetworks.Servodrivesystemincludingservodrivesandmotors.Positionmeasuringsystemismainlyusedgrating,orcirculargratingincrementaldisplacementencoder.

CNCsystemhardwarefromtheNCdevice,input/outputdevices,drivesandmachinelogiccontroldevices,electricalcomponents,betweenthefourpartsthroughtheI/Ointerfacetointerconnect.

NumericalcontroldeviceisthecoreofCNCsystem,itssoftwareandhardwaretocontroltheimplementationofvariousCNCfunctions.

ThehardwarestructureofnodevicebyCNCinstallationsintheprintedcircuitboardwithinfixingpatterncanbedividedintothebigboardstructureandfunctionmodule(smallboard)structure;PressCNCapparatushardwaremanufacturingmode,canbedividedintospecialstructureandpersonalcomputertypestructure;PressCNCapparatusinthenumberofmicroprocessorcanbedividedintosinglemicroprocessorstructureandmanymicroprocessorstructure.

(1)Largepanelstructureandfunctiontemplatesstructure

1)Largepanelstructure

PanelstructuresCNCsystemCNCequipmentfromthemaincircuitboard,positioncontrolpanels,PCboards,graphicscontrolpanel,additionalI/Oboardandpowersupplyunitandothercomponents.Themaincircuitboardprintedcircuitboardisbig;theothercircuitboardisasmallplate,insertedinthelargeprintedcircuitboardslot.Thisstructureissimilartothestructureofmicro-computer.

2)Functiontemplatesstructure

(2)Single-microprocessorstructureandmulct-microprocessorstructure

1)Single-microprocessorstructure

Inasingle-microprocessorstructure,onlyamicroprocessortofocusoncontrol,time-sharingdealswiththevarioustasksofCNCequipment.

2)melt-microprocessorstructure

Withtheincreaseinnumericalcontrolsystemfunctions,CNCmachinetoolstoimprovetheprocessingspeedofasinglemicroprocessorCNCsystemcannotmeettherequirement;therefore,manyCNCsystemsusesamulti-microprocessorstructure.Ifanumericalcontrolsystemhastwoormoremicroprocessors,eachmicroprocessorviathedatabusorcommunicationtoconnect,sharesystemmemoryandcommonI/Ointerfaces,eachprocessorsharingsystemPartofthework,whichismulti-processorsystems.

CNCsoftwareisdividedintoapplicationsoftwareandsystemsoftware.CNCsystemsoftwarefortherealizationofvariousfunctionsoftheCNCsystem,thepreparationofspecialsoftware,alsoknownascontrolsoftware,storedinthecomputerEPROMmemory.CNCSystemsfeatureavarietyofsettingsanddifferentcontrolschemes,andtheirsystemsoftwareinthestructureandsizevarywidely,butgenerallyincludeinputdataprocessingprocedures,computinginterpolationprocedures,speedcontrolprocedures,managementproceduresanddiagnosticprocedures.

(1)Inputdataprocessingprocedures

Itreceivesinputpartprogram,thestandardcode,saidprocessinginstructionsanddata

decoding,dataprocessing,accordingtotheprescribedformatforstorage.Somesystemsalsocalculatedtocompensate,orinterpolationoperationandspeedcontrolforpre-computation.Typically,theinputdataprocessingprogram,includinginput,decodinganddataprocessingthreeelements.

(2)Computinginterpolationprocedures

CNCworkpieceprocessingsystemaccordingtothedataprovided,suchascurvetype,start,end,etc.operations.Accordingtotheresultsofoperationsweresenttoeachaxisfeedpulse.Thisprocessiscalledinterpolationoperation.FeeddriveservosystemImpulsivetableorbyacorrespondingmovementofthetooltocompletetheproceduralrequirementsoftheprocessingtasks.

InterpolationforCNCsystemisthesideoftheoperation,whileprocessing,isatypicalreal-timecontrol,sotheinterpolationdirectlyaffectsthespeedofoperationthemachinefeedrate,andshouldthereforebepossibletoshortencomputationtime,whichisthepreparationofinterpolationComplementsthekeytotheprogram.

(3)Speedcontrolprocedures

Speedcontrolprogramaccordingtothegivenvaluecontrolthespeedofoperationofthefrequencyinterpolation,inordertomaintainapredeterminedfeedrate.Changesinspeedislarge,theneedforautomaticcontrolofaccelerationanddecelerationtoavoidspeeddrivesystemcausedbymutationsinstep.

(4)Managementprocedures

Managementproceduresresponsiblefordatainput,dataprocessing,interpolationprocessingservicesoperationsasthevariousproceduresforregulationandmanagement.Managementprocessbutalsoonthepanelcommand,theclocksignal,theinterruptcausedbyfaultsignalsforprocessing.

(5)Diagnosticprocedures

Diagnosticfeaturesarefoundintherunningsystemfailureinatimelymanner,andthatthetypeoffailure.Youcanalsorunbeforeorafterthefailure,checkthesystemmaincomponents(CPU,memory,interfaces,switches,servosystems,etc.)functionisnormal,andthatthesiteoffailure.

Machining

Anymachiningmusthavethreebasicconditions:machiningtools,workpieceandmachiningsports.Machiningtooledgeshouldbe,thematerialmustberigidthantheworkpiece.Differentformsoftoolstructureandcuttingmovementsconstitutedifferentcuttingmethods.Bladewithablade-shapedandhaveafixednumberofmethodsforcuttingtoolsforturning,drilling,boring,milling,planning,broaching,andsawing,etc.;edgeshapeandedgewithnofixednumberofabrasiveorabrasiveCuttingmethodsaregrinding,grinding,honingandpolishing.

Machiningisthemostimportantmachinerymanufacturingprocessingmethods.Althoughtheroughimprovemanufacturingprecision,casting,forging,extrusion,powdermetallurgyprocessingapplicationsonwidely,buttoadapttoawiderangeofmachining,

andcanachievehighaccuracyandlowsurfaceroughness,inManufacturingstillplaysanimportantroleintheprocess.Cuttingmetalmaterialshavemanyclassifications.Commonarethefollowingthreekinds.

Bycuttingprocessfeaturedistinguishingcharacteristicsofthedecisionprocessonthestructureofcuttingtoolsandcuttingtoolsandworkpiecerelativemotionform.Accordingtothetechnicalcharacteristicsofcuttingcanbedividedinto:turning,milling,drilling,boring,reaming,planning,shaping,slotting,broaching,sawing,grinding,grinding,honing,superfinishing,polishing,gearProcessing,thewormprocess,threadprocessing,ultra-precisionmachining,benchandscrapersandsoon.Bymaterialremovalrateandmachiningaccuracydistinctioncanbedividedinto:①rough:withlargedepthofcut,oneorafewtimesbytheknifeawayfromtheworkcutoutmostorallallowances,suchasroughturning,roughplanning,Roughmilling,drillingandsawing,etc.,roughmachiningprecisionhighefficiencylow,generallyusedasapre-processing,andsometimesalsoforfinalprocessing.②Semi-finishing:Generalroughingandfinishingasthemiddlebetweentheprocess,buttheworkpieceaccuracyandsurfaceroughnessonthelessdemandingposition,butalsocanbeusedasthefinalprocessing.③finishing:cuttingwithafinewaytoachievehighermachiningsurfaceaccuracyandsurfacequality,suchasfinecars,fineplanning,precisionhinges,grindingandsoon.Generalisthefinalfinishingprocess.④Finishingprocess:afterthefinish,theaimistoobtainasmallersurfaceroughnessandtoslightlyimprovetheaccuracy.Finishingprocessingallowanceissmall,suchashoning,grinding,ultra-precisiongrindingandsuperfinishingandsoon.⑤Modificationprocess:theaimistoreducethesurfaceroughness,toimprovethecorrosion,dustpropertiesandimproveappearance,butdoesnotrequirehigherprecision,suchaspolishing,sanding,etc.⑥ultra-precisionmachining:aerospace,lasers,electronics,nuclearenergyandothercutting-edgetechnologiesthatneedsomespecialprecisionparts,highaccuracyoverIT4,surfaceroughnesslessthanRa0.01microns.Thisneedtotakespecialmeasurestoultra-precisionmachining,suchasturningmirror,mirrorgrinding,chemicalmechanicalpolishingofsoftabrasive.

Distinguishedbymethodofsurfacemachining,theworkpieceistorelyonthemachinedsurfaceforcuttingtoolandtheworkpiecetoobtaintherelativemotion.Bysurfacemethods,cuttingcanbedividedintothreecategories.①tiptrajectorymethod:relyingonthetiprelativetothetrajectoryofthesurfacetoobtaintherequiredworkpiecesurfacegeometry,suchascylindricalturning,planningsurface,cylindricalgrinding,withtheformingsurface,suchasbyturningmode.Thetrajectorydependsonthetooltipprovidedbythecuttingtoolandworkpiecerelativemotion.②formingtoolmethod:shortformingmethod,withthefinalworkpiecesurfaceprofilethatmatchestheshapeformingcutterorgrindingwheel,suchasprocessingashapedsurface.Atthistimeformingpartofthemachinemovementwasreplacedbythebladegeometry,suchastheshapeofturning,millingandforminggrindingformingandsoon.Themoredifficultthemanufactureofformingcutter,machine-clamp-workpiece-toolformedbytheprocesssystemcanwithstandthecuttingforceislimited,formingmethodisgenerallyusedforprocessingshortshapedsurface.③generatingmethod:alsoknownasrotarycuttingmethod,cuttingtoolandworkpieceduringprocessingasarelativelydevelopedintoacampaigntool(orwheel)andtheworkpieceinstantaneouscenterlineofpurerollinginteractionbetweenthe

twomaintainacertainratiobetweenIsobtainedbyprocessingthesurfaceofthebladeinthismovementintheenvelope.Gearmachininghobbling,gearshaping,shaving,honing,andgrindingteeth(notincludingformgrindingteeth),etc.aregeneratingmethodprocessing.

PLC

EarlycalledtheprogrammablelogiccontrollerPLC(ProgrammableLogicController,PLC),whichismainlyusedtoreplacethelogiccontrolrelays.Withthetechnology,whichusesmicro-computertechnology,industrialcontroldevicefunctionhasbeengreatlyexceededthescopeoflogiccontrol,therefore,suchadevicetodaycalledprogrammablelogiccontroller,referredtoasthePC.However,inordertoavoidpersonalcomputer(PersonalComputer)intheshortconfusion,itwillbereferredtoasprogrammablelogiccontrollerPLC,plcsince1966,theU.S.DigitalEquipmentCorporation(DEC)developedthere,thecurrentUnitedStates,Japan,Germany,PLCGoodqualityandpowerful.

ThebasicstructureofProgrammableLogicController

A.Power

PLC'spowerinthewholesystemplaysaveryimportantrole.Ifyoudonothaveagood,reliablepowersystemisnotworking,sothePLCmanufacturersdesignandmanufactureofpowerveryseriously.GeneralACvoltagefluctuationsof+10%(+15%)range,youcannottakeothermeasurestoPLCtoconnectdirectlytotheACline.

B.Centralprocessingunit(CPU)

Centralprocessingunit(CPU)isthecentralPLCcontrol.ItisgivenbythefunctionofPLCsystemprogramfromtheprogrammerreceivesandstorestheuserprogramanddatatype;checkthepowersupply,memory,I/Oandtimeralertstatus,andtodiagnosesyntaxerrorsintheuserprogram.WhenthePLCintorun-time,firstitscansthescenetoreceivethestatusofvariousinputdevicesanddata,respectively,intoI/Oimagearea,andthenonebyonefromtheuserprogramreadstheuserprogrammemory,afterashellandpressProvisionsoftheDirectivetheresultoflogicorarithmeticoperationsintotheI/Oimageareaordataregister.Andtheentireuserprogramisfinished,andfinallyI/Oimageareaofthestateortheoutputoftheoutputregisterdatatotheappropriateoutputdevice,andsoontorununtilstopped.

TofurtherimprovethereliabilityofPLC,PLCisalsolargeinrecentyearsconstitutesaredundantdual-CPUsystem,orbythreevotingsystemsCPU.Thus,evenifaCPUfails,thewholesystemcanstillworkproperly.

C.Memory

Storagesystemsoftwareofmemorycalledsystemprogrammemory.Storageapplicationsoftwareofmemorycalledtheuserprogrammemory.

D.Inputandoutputinterfacecircuit

1,theliveinputinterfacecircuitbytheopticalcouplingcircuitandthecomputerinputinterfacecircuit,theroleofPLCandfieldcontrolofaninterfaceforinputchannels.

2,Fieldoutputinterfacecircuitbytheoutputdataregisters,interruptrequeststrobecircuitandintegratedcircuit,theroleofPLCoutputinterfacecircuitthroughtheon-site

implementationofpartsoftheoutputtothefieldcorrespondingcontrolsignal.

E.Functionmodule

Suchascounting,positioningmodules.

http://./doc/144c3331a36925c52cc58bd63186bceb18e8ed11.htmlmunicationmodule

SuchasEthernet,RS485,Prefab’s-DPcommunicationmodule.

数控系统

数控系统是数字控制系统简称，英文名称为NumericalControlSystem，早期是由硬件电路构成的称为硬件数控（HardNC），1970年代以后，硬件电路元件逐步由专用的计算机代替称为计算机数控系统。

计算机数控（Computerizednumericalcontrol,简称CNC）系统是用计算机控制加工功能，实现数值控制的系统。CNC系统根据计算机存储器中存储的控制程序，执行部分或全部数值控制功能，并配有接口电路和伺服驱动装置的专用计算机系统。

CNC系统由数控程序、输入装置、输出装置、计算机数控装置（CNC装置）、可编程逻辑控制器（PLC）、主轴驱动装置和进给（伺服）驱动装置（包括检测装置）等组成。

CNC系统的核心是CNC装置。由于使用了计算机，系统具有了软件功能，又用PLC代替了传统的机床电器逻辑控制装置，使系统更小巧，其灵活性、通用性、可靠性更好，易于实现复杂的数控功能，使用、维护也方便，并具有与上位机连接及进行远程通信的功能。

目前世界上的数控系统种类繁多，形式各异，组成结构上都有各自的特点。这些结构特点来源于系统初始设计的基本要求和工程设计的思路。例如对点位控制系统和连续轨迹控制系统就有截然不同的要求。对于T系统和M系统，同样也有很大的区别，前者适用于回转体零件加工，后者适合于异形非回转体的零件加工。对于不同的生产厂家来说，基于历史发展因素以及各自因地而异的复杂因素的影响，在设计思想上也可能各有千秋。例如，美国Dynapath系统采用小板结构，便于板子更换和灵活结合，而日本FANUC系统则趋向大板结构，使之有利于系统工作的可靠性，促使系统的平均无故障率不断提高。然而无论哪种系统，它们的基本原理和构成是十分相似的。

一般整个数控系统由三大部分组成，即控制系统，伺服系统和位置测量系统。控制系统按加工工件程序进行插补运算，发出控制指令到伺服驱动系统；伺服驱动系统将控制指令放大，由伺服电机驱动机械按要求运动；测量系统检测机械的运动位置或速度，并反馈到控制系统，来修正控制指令。这三部分有机结合，组成完整的闭环控制的数控系统。

控制系统主要由总线、CPU、电源、存贮器、操作面板和显示屏、位控单元、可编程序控制器逻辑控制单元以及数据输入/输出接口等组成。最新一代的数控系统还包括一个通讯单元，它可完成CNC、PLC的内部数据通讯和外部高次网络的连接。伺服驱动系统主要包括伺服驱动装置和电机。位置测量系统主要是采用长光栅或圆光栅的增量式位移编码器。

数控系统的硬件由数控装置、输入/输出装置、驱动装置和机床电器逻辑控制装置等组成，这四部分之间通过I/O接口互连。

数控装置是数控系统的核心，其软件和硬件来控制各种数控功能的实现。

数控装置的硬件结构按CNC装置中的印制电路板的插接方式可以分为大板结构和功能模块（小板）结构；按CNC装置硬件的制造方式，可以分为专用型结构和个人计算机式结构；按CNC装置中微处理器的个数可以分为单微处理器结构和多微处理器结构。

（1）大板结构和功能模板结构

1）大板结构

大板结构CNC系统的CNC装置由主电路板、位置控制板、PC板、图形控制板、附加I/O板和电源单元等组成。主电路板是大印制电路版，其它电路板是小板，插在大印制电路板上的插槽内。这种结构类似于微型计算机的结构。

2）功能模块结构

（2）单微处理器结构和多微处理器结构

1）单微处理器结构

在单微处理器结构中，只有一个微处理器，以集中控制、分时处理数控装置的各个任务。

2）多微处理器结构

随着数控系统功能的增加、数控机床的加工速度的提高，单微处理器数控系统已不能满足要求，因此，许多数控系统采用了多微处理器的结构。若在一个数控系统中有两个或两个以上的微处理器，每个微处理器通过数据总线或通信方式进行连接，共享系统的公用存储器与I/O接口，每个微处理器分担系统的一部分工作，这就是多微处理器系统。

CNC软件分为应用软件和系统软件。CNC系统软件是为实现CNC系统各项功能所编制的专用软件，也叫控制软件，存放在计算机EPROM内存中。各种CNC系统的功能设置和控制方案各不相同，它们的系统软件在结构上和规模上差别很大，但是一般都包括输入数据处理程序、插补运算程序、速度控制程序、管理程序和诊断程序。

（1）输入数据处理程序

它接收输入的零件加工程序，将标准代码表示的加工指令和数据进行译码、数据处理，并按规定的格式存放。有的系统还要进行补偿计算，或为插补运算和速度控制等进行预计算。通常，输入数据处理程序包括输入、译码和数据处理三项内容。

（2）插补计算程序

CNC系统根据工件加工程序中提供的数据，如曲线的种类、起点、终点等进行运算。根据运算结果，分别向各坐标轴发出进给脉冲。这个过程称为插补运算。进给脉冲通过伺服系统驱动工作台或刀具作相应的运动，完成程序规定的加工任务。

CNC系统是一边插补进行运算，一边进行加工，是一种典型的实时控制方式，所以，插补运算的快慢直接影响机床的进给速度，因此应该尽可能地缩短运算时间，这是编制插补运算程序的关键。

(3)速度控制程序

速度控制程序根据给定的速度值控制插补运算的频率，以保预定的进给速度。在速度变化较大时，需要进行自动加减速控制，以避免因速度突变而造成驱动系统失步。

(4)管理程序

管理程序负责对数据输入、数据处理、插补运算等为加工过程服务的各种程序进行调度管理。管理程序还要对面板命令、时钟信号、故障信号等引起的中断进行处理。

(5)诊断程序

诊断程序的功能是在程序运行中及时发现系统的故障，并指出故障的类型。也可以在运行前或故障发生后，检查系统各主要部件（CPU、存储器、接口、开关、伺服系统等）的功能是否正常，并指出发生故障的部位。

切削加工

任何切削加工都必须具备3个基本条件:切削工具、工件和切削运动。切削工具应有刃口，其材质必须比工件坚硬。不同的刀具结构和切削运动形式构成不同的切削方法。用刃形和刃数都固定的刀具进行切削的方法有车削、钻削、镗削、铣削、刨削、拉削和锯切等；用刃形和刃数都不固定的磨具或磨料进行切削的方法有磨削、研磨、珩磨和抛光等。

切削加工是机械制造中最主要的加工方法。虽然毛坯制造精度不断提高，精铸、精锻、挤压、粉末冶金等加工工艺应用日广，但由于切削加工的适应范围广，且能达到很高的精度和很低的表面粗糙度，在机械制造工艺中仍占有重要地位。金属材料的切削加工有许多分类方法。常见