自控原理课件1(英文版)

Chapter1:IntroductiontoAutomaticControl重点掌握:•控制系统的基本组成•基本的控制方式及反馈控制系统的特点•控制系统的性能要求Maincontents1-1Whatisacontrolsystem?1-2Whyarecontrolsystemsimportant?1-3Whatisanautomaticcontrolsystem?1-4Basiccomponentsandtypesofcontrolsystem.1-5Howtoevaluateaautomaticcontrolsystem?1-6Thedevelopmentofautomaticcontroltheory.1-1Whatisacontrolsystem?examplesControlofTrafficLightsPowerHeaterFurnaceSwitchFurnacetemperaturecontrolsystem1-1Whatisacontrolsystem?DesiredtemperaturefurnacethermometergasmixervalveairoperatorTemperaturecontrolsystem1-1Whatisacontrolsystem?waterlevelcontrolsystem1-1Whatisacontrolsystem?DefinitionofacontrolsystemAninterconnectionofcomponentsformingasystemconfigurationthatwillprovideadesiredsystemresponse.由相互关联的部件按一定的结构构成的系统，能够提供预期的系统响应。1-1Whatisacontrolsystem?1-2Whyarecontrolsystemsimportant?(1)控制系统无处不在.(2)提高产量，降低成本.(3)提高精度、可靠性.(4)能够在许多人不到达的场所发挥作用.furnacethermometergasmixervalveairDesiredtemperatureoperator1-3Whatisanautomaticcontrolsystem?Acontrolsystemwithoutpeopleinvolvediscalledautomaticcontrolsystem.Definitionofautomaticcontrolsystem1-3Whatisanautomaticcontrolsystem?TemperatureautomaticcontrolsystemGasMixerAirValveMotorAmplifierUTPotentiometerURAmplifierFurnaceThermocouple1-3Whatisanautomaticcontrolsystem?waterlevelautomaticcontrolsystem1-3Whatisanautomaticcontrolsystem?1.AccordingtotheformofgivensignalRegulatorSystemsversusServoSystems(恒值系统和随动系统）2.AccordingtowhetherthesystemissatisfiedthesuperpositionprincipleLinearSystemsversusNonlinearSystemAlinearsystemsatisfiesthepropertiesofsuperpositionandHomogeneity:(PrincipleofSuperposition).1-4typesandBasiccomponentsofcontrolsystems.SuperpositionPropertysystem1r1ysystem2y2rsystem21rr21yyHomogeneityPropertysystemrysystemayarPrincipleofsuperposition1-4typesandBasiccomponentsofcontrolsystems.3.Accordingtowhetherthesystem’sparametersarechangedwithtimeTime-InvariantSystemsversusTime-varyingSystem4.AccordingtotheformofthesignalContinuousSystemsversusDiscreteSystems5.AccordingtothenumberofI/OSISOSystemsversusMIMOSystems6.AccordingtothestructureofthesystemOpen-loopsystem,closed-loopsystem(feedbackcontrolsystems),CompoundControlsystems1-4typesandBasiccomponentsofcontrolsystems.x2x3Signal(variable)xxxComponents(devices)+-+x1eAdders(comparison)e=x1+x3-x2xExample:nextpagesTheblockdiagramdescriptionforacontrolsystem:ConvenienceBlockdiagramofcontrolsystems1-4typesandBasiccomponentsofcontrolsystems.1-4typesandBasiccomponentsofcontrolsystems.Desiredoutputresponse(Commandinput)ActuatingdeviceprocessOutputControllerplantExample:PowerHeaterFurnaceSwitch被控对象FurnaceSwitch&HeaterCommandinputOutputControllerPlantFurnacetemperaturecontrolsystem1-4typesandBasiccomponentsofcontrolsystems.Example:TankValve1LeverDisturbance(valve2)Valve1Valve2TankWaterLevelcontrolsystem1-4typesandBasiccomponentsofcontrolsystems.Example:TemperaturecontrolsystemGasMixerAirValveMotorAmplifierUTPotentiometerURAmplifierFurnaceThermocoupleValveMixerAirAmplifierFurnaceCAmplifierThermocoupleMotorURUT1-4typesandBasiccomponentsofcontrolsystems.Example:AnOpen-loopcontrolsystemutilizesanactuatingdevicetocontroltheprocessdirectlywithoutusingfeedback.Openloopcontrol开环控制(Open-loopControl)——系统的输出端与输入端之间不存在反馈回路，输出量对系统的控制作用没有影响。1-4typesandBasiccomponentsofcontrolsystems.Open-loopControlSystemTheoutputoftheopen-loopsystemhasnoeffectupontheinputsignal.Thereistheneedtoknowanaccuratemodelofindividualcomponents.C被控对象ControllerPlantRUPlantControllerMeasurementnCU1-4typesandBasiccomponentsofcontrolsystems.优点：简单，相对来说成本低缺点：对可能出现的被控量偏离给定值的偏差没有任何修正能力，抗干扰能力差，控制精度不高。Featuresofopen-loopcontrol1-4typesandBasiccomponentsofcontrolsystems.Aclosed-loopcontrolsystemusesameasurementofoutputandfeedbackofthesignaltocompareitwiththedesiredoutput(referenceorcommand).Closed-loopcontrolsystemsReferenceinputComparisonControllerPlantOutputMeasurementFeedbacksignal)1-4typesandBasiccomponentsofcontrolsystems.优点：抗干扰能力强，控制精度高缺点：复杂，有时会产生不稳定。Featuresoffeedbackcontrolsystems1-4typesandBasiccomponentsofcontrolsystems.CompoundControlsystemsCombinationofopen-loopandclosed-loopControllerPlantCFeedbackelementR—CompensatorControllerPlantCFeedbackelementR—Compensatorn1-4typesandBasiccomponentsofcontrolsystems.ObjectivesofcontrolTheobjectivesofthecontrolsystemistocontroltheoutputsinsomeprescribedmannerbytheinputsthroughtheelementsofcontrolsystems.通常目标规定为系统的输入。Ingeneral,theobjectivescanbeidentifiedwithinputs.1-4typesandBasiccomponentsofcontrolsystems.Basiccomponentsofcontrolsystems被控对象(plant,process)测量元件（sensor）可以对被控量进行测量，并转换成能与输入信号进行比较的量纲和数值，也称为反馈元件；比较环节（comparison）实现误差检测；执行机构（actuator）实现对受控对象的操控，起到功率放大的作用。控制律或控制算法（algorithm):控制器的核心。1-4typesandBasiccomponentsofcontrolsystems.AnalysisofautomaticcontrolsystemStep1确定系统任务；Step2明确：被控对象、被控量、给定值、测量元件、执行机构和比较元件；Step3叙述系统工作原理；Step4系统原理方框图。1-4typesandBasiccomponentsofcontrolsystems.terms1.被控对象（plant）指被控制的设备或过程2.控制器（控制装置controller）除了被控制对象之外的各部分的组合；3.控制系统(controlsystem)受控对象与控制装置构成控制系统。4.给定值（期望值、输入量reference/input）被控制量要求的变化规律(Excitationappliedtoacontrolsystemfromanexternalsource).1-4typesandBasiccomponentsofcontro