Controlinstrumentsandon-offcontrollaws控制儀表及位式控制規(guī)律控制儀表及位式控制規(guī)律Controlinstrumentsandon-offcontrollaws謝聰XieCong主講教師Teacher理解掌握控制儀表的使用方法Understandandmastertheuseofcontrolinstruments控制儀表及位式控制規(guī)律Controlinstrumentsandon-offcontrollaws有效地運(yùn)用位式控制規(guī)律Effectivelyapplyon-offcontrollawsCaseImport案例導(dǎo)入冬天用空調(diào)取暖時(shí)，設(shè)定好26℃，空調(diào)會(huì)先全力制熱，等室溫達(dá)到這個(gè)溫度，它就悄悄停下來(lái)；可過(guò)一會(huì)兒溫度降了點(diǎn)，它又立馬啟動(dòng)繼續(xù)工作。Whenusinganairconditionerforheatinginwinter,aftersettingitto26℃,theairconditionerwillfirstbeoperatedatfullcapacityforheating.Oncetheroomtemperaturereachesthissetting,itwillbequietlystopped;however,ifthetemperaturedropsabitafterawhile,itwillbeimmediatelystartedagaintocontinueworking.CaseImport案例導(dǎo)入冬天用空調(diào)取暖時(shí)，設(shè)定好26℃，空調(diào)會(huì)先全力制熱，等室溫達(dá)到這個(gè)溫度，它就悄悄停下來(lái)；可過(guò)一會(huì)兒溫度降了點(diǎn)，它又立馬啟動(dòng)繼續(xù)工作。Whenusinganairconditionerforheatinginwinter,aftersettingitto26℃,theairconditionerwillfirstbeoperatedatfullcapacityforheating.Oncetheroomtemperaturereachesthissetting,itwillbequietlystopped;however,ifthetemperaturedropsabitafterawhile,itwillbeimmediatelystartedagaintocontinueworking.控制儀表Controlinstruments位式控制規(guī)律On-offcontrollawsControlinstruments控制儀表Controlinstruments控制儀表控制規(guī)律的定義Definitionofcontrollaws控制儀表又稱控制器或調(diào)節(jié)器，其作用是把被控參數(shù)的測(cè)量值PV

和給定SV

進(jìn)行比較，得出偏差

e

后，按一定的控制（或調(diào)節(jié)）規(guī)律進(jìn)行運(yùn)算，輸出控制信號(hào)MV，以推動(dòng)執(zhí)行器動(dòng)作，實(shí)現(xiàn)對(duì)生產(chǎn)過(guò)程的自動(dòng)控制。Controlinstruments,alsoknownascontrollersorregulators,functionbycomparingthemeasuredvaluePVofthecontrolledparameterwiththesetvalueSVtoobtainthedeviation

e

andthenperformingcalculationsaccordingtoacertaincontrol(orregulation)lawtooutputacontrolsignalMV.Thissignaldrivestheactuatortoachieveautomaticcontroloftheproductionprocess.Controlinstruments控制儀表控制儀表分類Classificationofcontrolinstruments按工作能源可分為Canbeclassifiedaccordingtoworkingenergy電動(dòng)儀表Electricinstruments以AC220V或DC24V作為工作能源，其輸入輸出信號(hào)均采用DC0～10mA/DC0～10V或DC4～20mA/DC1～5V的標(biāo)準(zhǔn)信號(hào)。TheseuseAC220VorDC24Vfortheworkingenergysource,withinputandoutputstandardsignalsofDC0-10mA/DC0-10VorDC4-20mA/DC1-5V.Controlinstruments控制儀表控制儀表分類Classificationofcontrolinstruments按工作能源可分為Canbeclassifiedaccordingtoworkingenergy氣動(dòng)儀表Pneumaticinstruments以140kPa的氣壓信號(hào)作為工作能源，其輸入輸出信號(hào)均采用20～100kPa的標(biāo)準(zhǔn)氣壓信號(hào)。Theseuseapneumaticsignalof140kPafortheworkingenergysource,withinputandoutputstandardpneumaticsignalsof20-100kPa.Controlinstruments控制儀表控制儀表分類Classificationofcontrolinstruments按工作能源可分為Canbeclassifiedaccordingtoworkingenergy自力式儀表Self-poweredinstruments不需要專門提供工作能源。Thesedonotrequirethededicatedworkingenergysource.hhQ1Q1Q2液位控制/調(diào)節(jié)器Levelcontroller/regulatorQ?：流入量Q1:inflowrateQ2：流出量Q2:outflowrateh：液位高度h:liquidlevelheightOn-offcontrollaws位式控制規(guī)律On-offcontrollaws位式控制規(guī)律基本控制規(guī)律及特點(diǎn)Basiccontrollawsandcharacteristics所謂控制規(guī)律是指控制器的輸出值MV(ManipulationValue)與輸入偏差e之間的關(guān)系。Theso-calledcontrollawreferstotherelationshipbetweenthecontroller'soutputvalueMV(ManipulationValue)andtheinputdeviatione.

MV=f(e)

控制器的輸入信號(hào)e

由變送器送來(lái)的測(cè)量值PV（ProcessValue）和設(shè)定值SV（SettingValue）比較得出Thecontroller'sinputsignaleisobtainedbycomparingthemeasuredvaluePV(ProcessValue)sentbythetransmitterwiththesetvalueSV(SetValue).e=PV–SVe=SV–PV或orOn-offcontrollaws位式控制規(guī)律控制規(guī)律Controllaws斷續(xù)控制Discontinuouscontrol控制器輸出接點(diǎn)信號(hào)Thecontrolleroutputscontactsignals

雙位控制Two-positioncontrol

三位控制Three-positioncontrol連續(xù)控制ContinuouscontrolOn-offcontrollaws位式控制規(guī)律控制規(guī)律Controllaws斷續(xù)控制Discontinuouscontrol控制器輸出接點(diǎn)信號(hào)Thecontrolleroutputscontactsignals

雙位控制Two-positioncontrol

三位控制Three-positioncontrol雙位控制器只有兩個(gè)輸出值，對(duì)應(yīng)的執(zhí)行機(jī)構(gòu)只有開和關(guān)兩個(gè)極限位置，所以也被稱為開關(guān)控制。Atwo-positioncontrollerhasonlytwooutputvalues,andthecorrespondingactuatorhasonlytwoextremepositions:onandoff.Therefore,two-positioncontrolisalsoknownason-offcontrol.連續(xù)控制Continuouscontrol控制器輸出連續(xù)信號(hào)Thecontrolleroutputscontinuoussignals

比例（P）控制Proportional(P)control

比例積分控制（PI）Proportional-integralcontrol(PI)

比例微分控制（PD）Proportional-derivativecontrol(PD)

比例積分微分控制（PID）Proportional-integral-derivativecontrol(PID)On-offcontrollaws位式控制規(guī)律理想的雙位控制器輸出值MV

與輸入偏差e

之間的關(guān)系：TherelationshipbetweentheoutputvalueMVofanidealtwo-positioncontrollerandtheinputdeviatione:e

≥0（或

e

<0）時(shí)Whene≥0(ore<0)MVmaxMV=MVmine

≤0（或

e

>

0）時(shí)Whene≤0(ore>0)MV有中間區(qū)的雙位控制特性Characteristicsoftwo-positioncontrolwithanintermediatezoneMVmaxMVmine理想雙位控制特性Characteristicsofidealtwo-positioncontrolMVmaxMVmineMVOn-offcontrollaws位式控制規(guī)律例：雙位溫度控制系統(tǒng)Example:Two-positiontemperaturecontrolsystem～進(jìn)水Waterinlet出水Wateroutlet220VOn-offcontrollaws位式控制規(guī)律例：雙位溫度控制系統(tǒng)Example:Two-positiontemperaturecontrolsystem溫度低于給定值時(shí)，溫控器輸出高電平，繼電器閉合，加熱器通電加熱；Whenthetemperatureislowerthanthesetvalue,thetemperaturecontrolleroutputsahighlevel,therelayisclosed,andtheheaterispoweredonforheating;溫度高于給定值時(shí)，溫控器輸出低電平，繼電器斷開，加熱器斷電。whenthetemperatureishigherthanthesetvalue,thetemperaturecontrolleroutputsalowlevel,therelayisopened,andtheheaterispoweredoff.～進(jìn)水Waterinlet出水Wateroutlet220V溫度給定值SettemperatureOn-offcontrollaws位式控制規(guī)律二位式控制器電路原理圖Schematicdiagramoftwo-positioncontrollercircuit測(cè)量信號(hào)Measuredsignal給定信號(hào)Setsignal－＋＋∞U0二位式控制是一種最簡(jiǎn)單的控制/調(diào)節(jié)器，根據(jù)被調(diào)量偏差e符號(hào)的正、負(fù)，輸出MV只有兩個(gè)位置，高電平或低電平，可以作為一個(gè)電氣開關(guān)使用。Thetwo-positioncontrolleristhesimplestcontroller/regulator.Basedonthepositiveornegativesignofthedeviationeofthecontrolledvariable,theoutputMVhasonlytwopositions,highlevelorlowlevel.Therefore,itcanbeusedasanelectricalswitch.On-offcontrollaws位式控制規(guī)律雙位控制效果Two-positioncontroleffecttMVTT0ttMVTT0t有中間區(qū)的雙位控制效果Two-positioncontroleffectwithanintermediatezoneOn-offcontrollaws位式控制規(guī)律tMVTT0ttMVTT0t被控溫度在T0

上下振蕩，不能穩(wěn)定在T0

。ThecontrolledtemperatureoscillatesaboveandbelowT0andcannotbestabilizedatT0.雙位控制效果Two-positioncontroleffect有中間區(qū)的雙位控制效果Two-positioncontroleffectwithanintermediatezoneOn-offcontrollaws位式控制規(guī)律三位控制Three-positioncontrol控制器有三個(gè)輸出狀態(tài)值，可以控制兩個(gè)繼電器。Thecontrollerhasthreeoutputstatevaluesandcancontroltworelays.測(cè)量信號(hào)Measuredsignal給定1Setsignal1－＋＋∞U01－＋＋∞U02給定2Setsignal2三位控制器電路原理圖Schematicdiagramofthree-positioncontrollercircuitMVmaxMVmineMVe2e1關(guān)系曲線RelationshipcurveOn-offcontrollaws位式控制規(guī)律三位控制Three-positioncontrol控制器有三個(gè)輸出狀態(tài)值，可以控制兩個(gè)繼電器。Thecontrollerhasthreeoutputstatevaluesandcancontroltworelays.測(cè)量信號(hào)Measuredsignal給定1Setsignal1－＋＋∞U01－＋＋∞U02給定2Setsignal2三位控制器電路原理圖Schematicdiagramofthree-positioncontrollercircuitMVmaxMVmineMVe2e1關(guān)系曲線RelationshipcurveOn-offcontrollaws位式控制規(guī)律三位控制Three-positioncontrol控制器有三個(gè)輸出狀態(tài)值，可以控制兩個(gè)繼電器。Thecontrollerhasthreeoutputstatevaluesandcancontroltworelays.測(cè)量信號(hào)Measuredsignal給定1Setsignal1－＋＋∞U01－＋＋∞U02給定2Setsignal2三位控制器電路原理圖Schematicdiagramofthree-positioncontrollercircuitMVmaxMVmineMVe2e1關(guān)系曲線RelationshipcurveOn-offcontrollaws位式控制規(guī)律例：溫度三位控制系統(tǒng)Example:Temperaturethree-positioncontrolsystem溫度低于T1時(shí)，溫控器使繼電器1、2都吸合，加熱器1、2都通電加熱；WhenthetemperatureislowerthanT1,thetemperaturecontrollermakesbothrelay1andrelay2beclosed,andbothheater1andheater2arepoweredonforheating;溫度高于T1低于T2時(shí)，溫控器使繼電器1吸合、繼電器2斷開，只有加熱器1通電；whenthetemperatureishigherthanT1andlowerthanT2,thetemperaturecontrollermakesrelay1beclosedandmakesrelay2beopened,andonlyheater1ispoweredon;J1J2T2T112220V進(jìn)水Waterinlet出水Wateroutlet溫度高于T2時(shí)，繼電器1、2都斷開。whenthetemperatureishigherthanT2,bothrelay1andrelay2areopened.On-offcontrollaws位式控制規(guī)律溫度三位控制效果Temperaturethree-positioncontroleffect溫度偏差大時(shí)，升溫速度快；溫度偏差小時(shí)，小幅調(diào)整。Whenthetemperaturedeviationislarge,theheatingrateisfast;whenthetemperaturedeviationissmall,thereisaminoradjustment.tMVTT2T1tOn-offcontrollaws位式控制規(guī)律溫度三位控制效果Temperaturethree-positioncontroleffect溫度偏差大時(shí)，升溫速度快；溫度偏差小時(shí)，小幅調(diào)整。Whenthetemperaturedeviationislarge,theheatingrateisfast;whenthetemperaturedeviationissmall,thereisaminoradjustment.tMVTT2T1t要使調(diào)節(jié)過(guò)程平穩(wěn)準(zhǔn)確，必須使用控制輸出值能連續(xù)變化的控制器。Acontrollerwithacontinuouslyvariablecontroloutputvaluemustbeusedtomaketheregulationprocessstableandaccurate.CourseSummary課程小結(jié)CourseSummary課程小結(jié)輸出為有限離散狀態(tài)（如全開/全關(guān)、高/低電平），根據(jù)偏差閾值切換狀態(tài)。Theoutputisinalimiteddiscretestate(suchasfullyopened/fullyclosed,high/lowlevel),andthestateisswitchedaccordingtothedeviationthreshold.核心原理Coreprinciple結(jié)構(gòu)簡(jiǎn)單、成本低、易實(shí)現(xiàn)。Si