1ProcessControlSystems

過程控制系統(tǒng)CollegeofAutomation,ChongqingUniversity過程控制自動化重慶大學2OutlineoftheIntroductionWhatIsProcessControl?DefinitionAfewexamplesandforms一些例子和形式WhatDoesItDo?Differencesfromautomaticcontroltheory自動控制理論的差異Whattobecontrolled?HowDoesItDo?如何實現(xiàn)Formulatingtheproblem制定問題ControlEquipmentandProcessEquipment控制設(shè)備和工藝設(shè)備ModelingtheprocessoftheProblem建模過程的問題3IntroductiontoProcessControlOperator’sViewofProcessControl操作員的觀點的過程控制ADayinaLifeofaPlantOperator4WhatIsProcessControl?DefinitionThetechnologyofcontrollingaseriesofeventstotransformamaterialintoadesiredendproductiscalledprocesscontrol.控制技術(shù)的一系列事件把資料達到所希望的最終產(chǎn)品,被稱為過程控制Shortexamples:Makingoffireforcookingrice(primitiveandmodern)Thefly-ballgovernorforsteamenginecontrol(1774)短的例子:讓火煮米飯(原始的和現(xiàn)代)州長的fly-ball蒸汽發(fā)動機控制(1774)Tendencyofindustrialprocesscontrolbeingcomputerized,beingautomatized,andbeinginstrumentedwithsmartsensorsandMEMS工業(yè)過程控制的趨勢在計算機化,在潛意識中自動使用,被裝備智能傳感器和微機電系統(tǒng)(MEMS)5WhatIsProcessControl?

AFewExamplesFlowControlinOilrefineryPlant:Dowerunaroundtheplanttoadjustthevalveswhenrequired?流量控制,是煉油廠植物:我們到處跑植物調(diào)節(jié)閥門在需要的時候嗎?6WhatIsProcessControl?

Manual手冊AutomatedpHcontrolAFewExamples2.pHControl7WhatIsProcessControl?AFewExamples:3.Roomtemperaturecontrol8WhatIsProcessControl?AFewExample4.WattCentralfugalSpeedGovernor

瓦特Centralfugal調(diào)速器9WhatIsProcessControl?AFewExamples5.LevelControl液位控制10WhatIsProcessControl?AFewExamples6.CrossDirectionProceControl十字方向過程控制Severalhundredsensorsandactuators,Millisecondoperation,Controllingpaperthicknesstowithinmicrons!幾百傳感器和執(zhí)行器,微操作,控制紙張厚度和在微米!11WhatIsProcessControl?AFewExamples7.DiscreteManufacturingProcesses離散型制造過程12WhatIsProcessControl?

AFewExamples8.Typicalcontinuousprocesses典型的連續(xù)過程13WhatIsProcessControl?

AFewExamples9.Typicalnon-continuousprocesses14WhatIsProcessControl?AFewExamples10.ASemi-ContinuousProcess半連續(xù)過程Howlargeshouldthetankvolumebe?油箱體積是多大呢？15WhatIsProcessControl?Sample-Plant:MillWideProcessControl軋機廣泛的過程控制16WhatIsProcessControl?SampleSoftware:HoneywellIntellimap樣品軟件:霍尼韋爾Intellimap17WhatIsProcessControl?SummaryoftheExamples-Forms總結(jié)的例子-形式DiscreteManufacturing,Motion,andPackaging離散型制造、運動、和包裝RoboticAssemblyLineinAutomotiveProduction機械的汽車生產(chǎn)流水線MetalStampingforthediscretepiecesofproduct五金沖壓為離散件產(chǎn)品Continuous

Production

ofFuels,Chemicals連續(xù)生產(chǎn)的燃料、化學品RoomTemperatureControl室溫控制NucleusChemicalReactor核化學反應器BatchProductionofintermediate/endproducts批量生產(chǎn)中間/終端產(chǎn)品AdhesivesandgluesFood,Beverages,andMedicine18WhatIsProcessControl?Tedency:BeingCompueterized,Automatized,andInstrumentedbysmartsensorsandMEMS計算機化，自動化，和動態(tài)化由智能傳感器和微機電系統(tǒng)Sensors,local

indicators,andvalvesintheprocess傳感器、當?shù)氐闹笜?和閥門在這個過程中ValveopeningdeterminedbythesignalfromcomputerDisplaysofvariables,calculations,commandstovalvesandhistoricaldataareinthecentralizedcontrolcenter.顯示變量的影響,計算,命令對閥門和歷史數(shù)據(jù)是在中央控制中心19WhatDoesItDo?DifferencesfromAutomaticControlTheory自動控制理論的差異UsingControlTheoryasaToolSolvingtheReal-WorldProblemsforMaintainingcontrolledvariablesatthedesiredvalues保持控制變量在期望值Manufacturingproductswithconsistentquality

whenrawmaterialpropertieschange?生產(chǎn)質(zhì)量穩(wěn)定的產(chǎn)品，原料性質(zhì)改變時？Respondingdangeroussituationswithgiventime危險的情況下和給定的時間響應BeingSpecializedbytransducer作為專業(yè)的傳感器SmartsensorsMEMS

微機電系統(tǒng)20WhatDoesItDo?WhatToBeControlled?TypicalControlledVariablesTemperature,Pressure,Flow,Level,Concentration濃度Physicalproperty物理性質(zhì)BeyondtheTypicalPosition,Velocity,andAccelerationinMotion位置、速度和加速度運動……21HowDoesItDo?FormulatingtheProblemStatement制訂問題的聲明ProblemStatement:Heatingupthetemperatureinaroomisaprocess:havingthespecific,desiredoutcometoreach,為了達到具體的，理想的結(jié)果maintainingadefinedtemperature(setpoint),keepingtemperatureconstantovertime.一直保持溫度恒定22HowDoesItDo?FormulatingtheProblemTerminologyintheprocess制定問題術(shù)語過程中ThetemperatureistheControlledVariable(CV)TheheaterstateiscalledtheManipulatedVariable加熱狀態(tài)被稱為操縱變量FactorscausingCVtodeviatefromtheirsetpointsiscalledtheDisturbanceor“Load"

Variables造成控制變量偏離設(shè)定值被稱為“負載“變量或干擾23HowDoesItDo?FormulatingtheProblemControllingthetemperatureTheTemperatureCyclesPeriodically溫度周期定期24HowDoesItDo?Control(verb)FeedbackControl(noun)tomaintaindesiredconditionsinaphysicalsystembyadjustingtheselectedvarialblesinthesystem保持理想條件在一個物理系統(tǒng)通過調(diào)節(jié)系統(tǒng)中變量makesuseofanoutputofasystemtoinflunceaninputtothesamesystem利用輸出系統(tǒng)影響一個輸入在相同的系統(tǒng)中Input=CauseOutput=Effect25HowDoesItDo?

26HowDoesItDo?TwoClassesofProcessControl兩級過程控制Regulatorycontrol-disturbancechange常規(guī)控制ThetransientbehaviorwhenadisturbanceentersAcontrolsystemshouldbeabletoreturneachcontrolledvariablebacktoitssetpoint.當一個擾動暫態(tài)行為進入一個控制系統(tǒng)應該能夠恢復各被控變量應該能夠恢復回它的設(shè)定Servoingcontrol-setpointchange伺服控制ThesetpointsignalischangedThemanipulatedvariableisadjustedappropriatelytoachievethenewoperatingconditions.被控變量能達到新的平衡27HowDoesItDo?ControllingtheTemperatureFromFeebackControlStandpoint28HowDoesitDo?Stability–ControlEvaluation穩(wěn)定,控制評價Delaysinthesystemandfeedbackloop,延遲系統(tǒng)和反饋回路causingthecorrectionsignaltobein-phasecausingtheerrorsignalchangeout-of-phasetwosignalsbecomeadditive–causinginstability修正信號,使同步造成誤差信號改變異相兩個信號成為添加劑-引起系統(tǒng)不穩(wěn)定Avoidinginstabilitytuningofthesystemanddamping,attheexpenseofreductionintheresponsetimeofthesystem.調(diào)節(jié)系統(tǒng)、阻尼、犧牲系統(tǒng)的響應時間29HowDoesitDo?Regulation–ControlEvaluationThedeviationfromthesetpoint從設(shè)置點的偏差,itshouldbeastightaspossible它應該盡可能的接近itisexpressedasapercentageofthesetpoint它是以百分比表示的設(shè)置點.Asmallerrorisalwayspresentitisusuallyamplifiedtodrivetheactuator它通常是放大用以驅(qū)動執(zhí)行器thesmallertheerror,thehigherthegaininstability越小的誤差,更高的增益?不穩(wěn)定.Anexample,thesetpointmaybe120oC,theregulationmaybe120±2.5oC,allowingtemperaturetovaryfrom117.5to122.5oC30HowDoesitDo?TransientResponse–ControlEvaluation瞬態(tài)響應Reactiontimetoasuddenchange,e.g.,一個突然的改變的反應時間asuddenincreaseinmaterialdemand,物質(zhì)需求的突然增加causingachangeinmeasuredvariableorinsetpoint.造成測量變量或設(shè)定值的變化Thereactioncanbespecifiedasadampenedresponseoralimiteddegreeofovershootofthemeasuredvariable反應可以被指定為阻尼響應或有限度的測量變量,Returningthemeasuredvariabletothesetpointinaspecifiedtime返回變量設(shè)定值在一個指定的時間31HowDoesItDo?ControlEvaluation控制效果評價Beingusedtosatisfiedthethreebasicneeds:用來滿足三個基本的需要ReducetheinfluenceofexternaldisturbancesPromotethestabilityoftheprocessEnhancetheperformanceoftheprocess32HowDoesItDo?ControllingtheTemperatureFromEquipmentStandpoint:

FourBasicElementsinaControlSystem四個基本要素的控制系統(tǒng)33HowDoesItDo?ControllingtheTemperatureControlEquipment34HowDoesItDo?ControllingtheTemperatureProcessEquipment35HowDoesItDo?ControlEquipmentExample1needtoregulatetheflow需要調(diào)節(jié)流量robustlyshutoffifneeded需要穩(wěn)定的開關(guān)36HowDoesItDo?ControlEquipmentExample2lowflowresistancewhenopen開路時電阻低流量infrequentlyusedbutneedreliability不經(jīng)常使用但需要牢固37HowDoesItDo?ControlEquipment-Example3

needgoodrangeability,需要良好的可調(diào)范圍flowresistanceokay,流阻好robustshutoffneeded魯棒關(guān)閉需要38HowDoesItDo?ControlEquipmentExample4lowflowresistance低流阻goodcontrolabilities39Example5notacontrolvalve,ventsifpressureistoohigh不能控制閥口，如果壓力過高HowDoesItDo?ExamplesofControlEquipment40HowDoesItDo?ControlEquipmentProcessEquipment–YourExamples?Dependingontheapplicationareas根據(jù)應用領(lǐng)域Beingcharacterizedwiththespecialknowledge作為具有的特別的知識Example6

preventbackflow防止回流41HowDoesItDo?TheoreticalModeling理論模型Physical/chemicallaws(fundamental,global)Material/energybalancesHeat,mass,andmomentumtransferThermodynamics,chemicalkinetics

Physicalpropertyrelationships物理/化學法(基本,全球)物質(zhì)/能量守恒熱量、質(zhì)量、動量傳遞熱力學、化學動力學物理性質(zhì)的關(guān)系42HowDoesItDo?TheoreticalModelingConservationLaw

守恒律ConservationofComponenti43IntroductiontoProcessControlTheoreticalModelingThefirstlawofthermodynamics熱力學第一定律

44IntroductiontoProcessControl介紹過程控制AspectsofTheoreticalModelling方面的理論模型

Modelcomplexityassumptions模型復雜性的假設(shè)

Computationallyexpensive(notreal-time)計算量大的

Expensive/time-consumingforextrapolationandscale-up昂貴/費時的推斷規(guī)模Noexperimentaldataisrequiredformodeling(datarequiredforvalidationandfitting)沒有實驗數(shù)據(jù)建模所需(所需的資料驗證和配件)45IntroductiontoProcessControlEmpiricalModeling(BlackBox)LargenumberofunknownparametersBeingobtainedquickly(e.g.,linearregression)ModelstructureissubjectiveDangeroustoextrapolate實證建模（黑盒）

大量的未知參數(shù)

迅速獲得（例如，線性回歸）

模型的結(jié)構(gòu)是主觀的

危險推斷46IntroductiontoProcessControlSemi-EmpiricalModellingCompromisingoffirsttwoapproachesModelstructuremaybesimplerTypically2to10physicalparametersestimated

(e.g.,nonlinearregression)Goodversatility,allowingextrapolationRunningonlineinreal-time半實證模型

犧牲前兩種方法

模型的結(jié)構(gòu)可能是簡單的

通常2到10個物理參數(shù)