控制工程(周川)ac-教學課件

References

(參考教材）RichardC.DorfandRobertH.Bishop.ModernControlSystems.10thedition,SciencePress.GeneFranklin,J.D.PowellandAbbas.Emami-Naeini.FeedbackControlofDynamicSystems.5thedition

PrenticeHall.GC.GoodwinandSF.Graebe.ControlSystemDesign.TsinghuaUniversityPress.胡壽松.自動控制原理（第5版）.北京：科學出版社，2019.SignificanceControlengineeringisanexcitingandchallengingfield.Itisamultidisciplinarysubject,andacorecourseintheengineeringcurriculum.Itiswidelyappliedtothefieldofindustryandagriculture,eventothesociological,biological,ecologicalandeconomicsystems.Itisespeciallyusedinhigh-technologyareassuchasspacecraftcontrolsystem.BilingualCourse

（雙語課程）

Language:BothEnglishandChineseEmphasis:Content,i.e.basicconceptandbasicprinciplesofautomaticcontrolGrasporenrichmajorterminologyImprovetheabilitytoreadspecialityreferencesormaterialsEnhancethecommunicationabilityonacademicproblemTheExcitementofControlEngineeringincreasedproductivityimprovedperformanceorproductqualitywasteandemissionminimizationenvironmentalprotectionhighersafetyControlEngineeringispresentinvirtuallyallmodernengineeringsystemsControlisakeytechnologywithrespectto:Ch1IntroductiontoControlSystemBasicConceptofControlSystemHistoryandDevelopmentofAutomaticControlTheMechanismofFeedbackControlExamplesofModernControlSystem1.1BasicConceptofControlSystemAControlSystemisaninterconnectionofcomponentsformingasystemconfigurationthatwillprovideadesiredsystemresponse.Thebasisforsystemanalysisanddesignislinearsystemtheory.(ClassicalControltheorywillbeemphasizedinthiscourse)Controlsystemhastwobasicstructure:Open-loopsystemClosed-loopsystemAnopen-loopControlSystemutilizesanactuatingdevicetocontroltheprocessdirectlywithoutusingfeedback.Anopen-loopcontrolsystemAclosed-loopcontrolsystemusesameasurementoftheoutputandfeedbackofthissignaltocompareitwiththedesiredoutput.(Thedesiredoutput

referenceorcommandinput).Aclosed-loopcontrolsystem

Aclosed-loopcontrolsystemusuallyconsistsofthefollowingelements:PlantorProcesstobecontrolledObjectivesorPerformanceActuatorSensorsCommunicationsControllers/AlgorithmsControlisamultidisciplinarysubjectControldesignaimstoachieveadesiredlevelofperformanceinthefaceofdisturbancesanduncertainty.PlantorProcess

Processorplanttobecontrolledcanberepresentedbycause-effectrelationship.(modelingproblem)Thusacontrolengineerneedstobefamiliarwiththe

"physics"oftheprocessunderstudy.Thatincludesa

rudimentaryknowledgeofthebasicenergybalance,

mass

balanceandmaterialflowsinthesystem.ManipulatorsObjectives/performance

Beforedesigningsensors,actuatorsorcontrolarchitectures,itisimportanttoknowthegoal,thatis,toformulatethecontrolobjectives.Thisincludes:whatdoesonewanttoachieve(energyreduction,yieldincrease,...)whatvariablesneedtobecontrolledtoachievetheseobjectiveswhatlevelofperformanceisnecessary(stability,accuracy,speed,

...)

Sensors

Sensorsaretheeyesoffeedbackcontrolenablingonetoseewhatisgoingon.Indeed,thatmeans:

Ifyouwanttocontrolit,youneedtomeasureit.Actuators

Oncesensorsareinplacetoreportthestateofa

process,thenthenextissueistheabilitytoaffect,oractuate,thesysteminordertomovetheprocessfromthecurrentstatetoadesiredstate.ACMotorCommunications

Interconnectingsensorstoactuators,involvestheuseofcommunicationsystems.Atypicalplantcanhavemanythousandsofseparatesignalstobesentoverlongdistances.Thusthedesignofcommunicationsystemsandtheirassociatedprotocolsisanimportantaspectofmoderncontrolengineering.Forexample,Networkedcontrolsystems(NCS)isahottopicnowadays.Controllers/Algorithms

Finally,wecometotherealheart

ofcontrolengineeringi.e.thecontrollersoralgorithmsthatconnectthesensorstotheactuators.Itiseasytounderstandtheimportanceandeffectofcontrollers.

Asasimpleexamplefromourdailyexperience,considertheproblemofplayingtennisattopinternationallevel.Onecanreadilyacceptthatoneneedsgoodeyesight(sensors)andstrongmuscles(actuators)toplaytennis,buttheseattributesarenotsufficient.Indeedeye-handcoordination(i.e.control)isalsocrucialtosuccess.BetterControl ProvideshighperformancebycombiningsensorsandactuatorsinmoreintelligentwaysBetterActuators ProvidemoreEnergyBetterSensorsProvidebetterVisionIllustrationsofControl1.2HistoryandDevelopment

ofAutomaticControlfascinatinghistorydatebackto300B.C,suchaswaterlevelregulationmechanismandwaterclock.

JamesWatt’sflyballgovernorin1769J.C.MaxwellformulatesamathematicalmodelforagovernorcontrolHenryFord’sassemblylineforautomobileproductionin1913H.S.Black&H.W.BodeanalyzesfeedbackamplifiersatBellTelephoneLabin1927.Auto-pilots,gun-positioningsystem,radarantennacontrolsystemandothermilitarysystemsinWorldWarII.State-variablemodelsandoptimalcontroldevelopedin1960’s-1970’s(spaceage)Robustcontrolwidelystudiedin1980’sIntelligentcontrolbecomeshottopicnowadays.Cybernetics(1948)ClassiccontrolModerncontrolLarge-scalesystemcontrolRobustandIntelligentcontrolDevelopmentofControlTheory1.3TheMechanismofFeedbackControlFeedbackisthefoundationforclosed-loopcontrolsystemanalysisanddesign.Feedbackcontrolsystemistocontroltheprocessbyusingthedifferencebetweentheoutputandreferenceinput.NegativefeedbackPositivefeedbackDefinitionfromN.Wiener

“Feedbackisamethodofcontrollingasystembyinsertingintoittheresultofitspastperformance”

ManualControlSystemAutomobilesteeringcontrolsystemDesireddirectionoftravelActualdirectionoftravelTimetResponse–DirectionoftravelStartpointDestinationAutom