數(shù)控系統(tǒng) 外文翻譯 外文文獻 英文文獻

數(shù)控系統(tǒng)外文翻譯外文文獻英文文獻_文檔視界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.

數(shù)控系統(tǒng)

數(shù)控系統(tǒng)是數(shù)字控制系統(tǒng)簡稱，英文名稱為NumericalControlSystem，早期是由硬件電路構成的稱為硬件數(shù)控（HardNC），1970年代以后，硬件電路元件逐步由專用的計算機代替稱為計算機數(shù)控系統(tǒng)。

計算機數(shù)控（Computerizednumericalcontrol,簡稱CNC）系統(tǒng)是用計算機控制加工功能，實現(xiàn)數(shù)值控制的系統(tǒng)。CNC系統(tǒng)根據計算機存儲器中存儲的控制程序，執(zhí)行部分或全部數(shù)值控制功能，并配有接口電路和伺服驅動裝置的專用計算機系統(tǒng)。

CNC系統(tǒng)由數(shù)控程序、輸入裝置、輸出裝置、計算機數(shù)控裝置（CNC裝置）、可編程邏輯控制器（PLC）、主軸驅動裝置和進給（伺服）驅動裝置（包括檢測裝置）等組成。

CNC系統(tǒng)的核心是CNC裝置。由于使用了計算機，系統(tǒng)具有了軟件功能，又用PLC代替了傳統(tǒng)的機床電器邏輯控制裝置，使系統(tǒng)更小巧，其靈活性、通用性、可靠性更好，易于實現(xiàn)復雜的數(shù)控功能，使用、維護也方便，并具有與上位機連接及進行遠程通信的功能。

目前世界上的數(shù)控系統(tǒng)種類繁多，形式各異，組成結構上都有各自的特點。這些結構特點來源于系統(tǒng)初始設計的基本要求和工程設計的思路。例如對點位控制系統(tǒng)和連續(xù)軌跡控制系統(tǒng)就有截然不同的要求。對于T系統(tǒng)和M系統(tǒng)，同樣也有很大的區(qū)別，前者適用于回轉體零件加工，后者適合于異形非回轉體的零件加工。對于不同的生產廠家來說，基于歷史發(fā)展因素以及各自因地而異的復雜因素的影響，在設計思想上也可能各有千秋。例如，美國Dynapath系統(tǒng)采用小板結構，便于板子更換和靈活結合，而日本FANUC系統(tǒng)則趨向大板結構，使之有利于系統(tǒng)工作的可靠性，促使系統(tǒng)的平均無故障率不斷提高。然而無論哪種系統(tǒng)，它們的基本原理和構成是十分相似的。

一般整個數(shù)控系統(tǒng)由三大部分組成，即控制系統(tǒng)，伺服系統(tǒng)和位置測量系統(tǒng)?？刂葡到y(tǒng)按加工工件程序進行插補運算，發(fā)出控制指令到伺服驅動系統(tǒng)；伺服驅動系統(tǒng)將控制指令放大，由伺服電機驅動機械按要求運動；測量系統(tǒng)檢測機械的運動位置或速度，并反饋到控制系統(tǒng)，來修正控制指令。這三部分有機結合，組成完整的閉環(huán)控制的數(shù)控系統(tǒng)。

控制系統(tǒng)主要由總線、CPU、電源、存貯器、操作面板和顯示屏、位控單元、可編程序控制器邏輯控制單元以及數(shù)據輸入/輸出接口等組成。最新一代的數(shù)控系統(tǒng)還包括一個通訊單元，它可完成CNC、PLC的內部數(shù)據通訊和外部高次網絡的連接。伺服驅動系統(tǒng)主要包括伺服驅動裝置和電機。位置測量系統(tǒng)主要是采用長光柵或圓光柵的增量式位移編碼器。

數(shù)控系統(tǒng)的硬件由數(shù)控裝置、輸入/輸出裝置、驅動裝置和機床電器邏輯控制裝置等組成，這四部分之間通過I/O接口互連。

數(shù)控裝置是數(shù)控系統(tǒng)的核心，其軟件和硬件來控制各種數(shù)控功能的實現(xiàn)。

數(shù)控裝置的硬件結構按CNC裝置中的印制電路板的插接方式可以分為大板結構和功能模塊（小板）結構；按CNC裝置硬件的制造方式，可以分為專用型結構和個人計算機式結構；按CNC裝置中微處理器的個數(shù)可以分為單微處理器結構和多微處理器結構。

（1）大板結構和功能模板結構

1）大板結構

大板結構CNC系統(tǒng)的CNC裝置由主電路板、位置控制板、PC板、圖形控制板、附加I/O板和電源單元等組成。主電路板是大印制電路版，其它電路板是小板，插在大印制電路板上的插槽內。這種結構類似于微型計算機的結構。

2）功能模塊結構

（2）單微處理器結構和多微處理器結構

1）單微處理器結構

在單微處理器結構中，只有一個微處理器，以集中控制、分時處理數(shù)控裝置的各個任務。

2）多微處理器結構

隨著數(shù)控系統(tǒng)功能的增加、數(shù)控機床的加工速度的提高，單微處理器數(shù)控系統(tǒng)已不能滿足要求，因此，許多數(shù)控系統(tǒng)采用了多微處理器的結構。若在一個數(shù)控系統(tǒng)中有兩個或兩個以上的微處理器，每個微處理器通過數(shù)據總線或通信方式進行連接，共享系統(tǒng)的公用存儲器與I/O接口，每個微處理器分擔系統(tǒng)的一部分工作，這就是多微處理器系統(tǒng)。

CNC軟件分為應用軟件和系統(tǒng)軟件。CNC系統(tǒng)軟件是為實現(xiàn)CNC系統(tǒng)各項功能所編制的專用軟件，也叫控制軟件，存放在計算機EPROM內存中。各種CNC系統(tǒng)的功能設置和控制方案各不相同，它們的系統(tǒng)軟件在結構上和規(guī)模上差別很大，但是一般都包括輸入數(shù)據處理程序、插補運算程序、速度控制程序、管理程序和診斷程序。

（1）輸入數(shù)據處理程序

它接收輸入的零件加工程序，將標準代碼表示的加工指令和數(shù)據進行譯碼、數(shù)據處理，并按規(guī)定的格式存放。有的系統(tǒng)還要進行補償計算，或為插補運算和速度控制等進行預計算。通常，輸入數(shù)據處理程序包括輸入、譯碼和數(shù)據處理三項內容。

（2）插補計算程序

CNC系統(tǒng)根據工件加工程序中提供的數(shù)據，如曲線的種類、起點、終點等進行運算。根據運算結果，分別向各坐標軸發(fā)出進給脈沖。這個過程稱為插補運算。進給脈沖通過伺服系統(tǒng)驅動工作臺或刀具作相應的運動，完成程序規(guī)定的加工任務。

CNC系統(tǒng)是一邊插補進行運算，一邊進行加工，是一種典型的實時控制方式，所以，插補運算的快慢直接影響機床的進給速度，因此應該盡可能地縮短運算時間，這是編制插補運算程序的關鍵。

(3)速度控制程序

速度控制程序根據給定的速度值控制插補運算的頻率，以保預定的進給速度。在速度變化較大時，需要進行自動加減速控制，以避免因速度突變而造成驅動系統(tǒng)失步。

(4)管理程序

管理程序負責對數(shù)據輸入、數(shù)據處理、插補運算等為加工過程服務的各種程序進行調度管理。管理程序還要對面板命令、時鐘信號、故障信號等引起的中斷進行處理。

(5)診斷程序

診斷程序的功能是在程序運行中及時發(fā)現(xiàn)系統(tǒng)的故障，并指出故障的類型。也可以在運行前或故障發(fā)生后，檢查系統(tǒng)各主要部件（CPU、存儲器、接口、開關、伺服系統(tǒng)等）的功能是否正常，并指出發(fā)生故障的部位。

切削加工

任何切削加工都必須具備3個基本條件:切削工具、工件和切削運動。切削工具應有刃口，其材質必須比工件堅硬。不同的刀具結構和切削運動形式構成不同的切削方法。用刃形和刃數(shù)都固定的刀具進行切削的方法有車削、鉆削、鏜削、銑削、刨削、拉削和鋸切等；用刃形和刃數(shù)都不固定的磨具或磨料進行切削的方法有磨削、研磨、珩磨和拋光等。

切削加工是機械制造中最主要的加工方法。雖然毛坯制造精度不斷提高，精鑄、精鍛、擠壓、粉末冶金等加工工藝應用日廣，但由于切削加工的適應范圍廣，且能達到很高的精度和很低的表面粗糙度，在機械制造工藝中仍占有重要地位。金屬材料的切削加工有許多分類方法。常見