自动控制原理综合

PrinciplesofAutomaticControlPrinciplesofAutomaticControl自动控制原理Topic(Chapter1intext顾申申Shenshen(Kevin)GuPh.D.CUHK),AssociateProfessorDepartmentofShanghaiBeforetheWhatdoyouunderstandBeforetheWhatdoyouunderstandbytheAutomaticGiveone/twoexamples,maybeablockdiagram,(2-32LearningOutcomesforTopicLearningOutcomesforTopicAftercompletingthistopic,youwillbeableDefineacontrolsystemanddescribesomeDescribehistoricaldevelopmentsleadingtomoderndaycontrolDescribethebasicfeaturesandconfigurationsofcontrolDescribecontrolsystemsanalysisanddesignDescribeacontrolsystem’sdesignDescribethebenfitfromstudyingcontrol3OutlineforTopicBriefOutlineforTopicBriefAHistoryofControlSystemAnalysisandDesignTheDesignComputer-Aided4NewterminologiesinthisControlSystemInput输入Output输出Disturbance干扰Integral积分NewterminologiesinthisControlSystemInput输入Output输出Disturbance干扰Integral积分Differential微分FeedbackSteady-stateResponse稳态响应NaturalResponse自然响应ForcedResponse强制响应Stability稳定性BlockDiagram方框图Schematic原理图Transferfunction传递函数5BriefControlsystemisanBriefControlsystemisanintegralpartofthesocietyandareallaroundus.–––––––––Humanbody(controlofpressure,sugaretc.)Heating/Air-Con.SystemIndustrialprocesses(rolling,papermakingetc))Chemical/Industrialprocesses(Beermaking)DamlevelcontrolAntennapositioncontrol(Insidecoveroftextbook)RoboticDevicesLet’swatchavideoofrobotic(floor6BriefIntroduction:ControlSystemAcontrolsystemconsistsofprocesses(combinationofsubprocessesand/orplant)BriefIntroduction:ControlSystemAcontrolsystemconsistsofprocesses(combinationofsubprocessesand/orplant)assembledforthepurposeofobtainingadesiredoutputwithadesiredperformance,givenaspecificinputordisturbances.7AnExampleofElevator:DiscussAnExampleofElevator:DiscusstheinputandoutputofanDiscussseveralaspectsweshouldfocusonwhendesigningan8AnExampleofElevator:ElevatorAnExampleofElevator:Elevator9BriefIntroduction:AdvantagesofControlWhatBriefIntroduction:AdvantagesofControlWhatisthe––––AmplifyPower(Antennasystem,Industrialcontrol)RemoteControl(Robot,rescuevehicle,satellite)Convenienceofinputform(Heatingsystem)Compensationfordisturbances(steering&alloftheThesearenotAHistoryofControlLiquidlevelAHistoryofControlLiquidlevelcontrol(300BCGreeks,waterclock:constantflowofwaterfromatank)–SelffillingoillampbyAHistoryofControlSystemsSteamAHistoryofControlSystemsSteamPressure&TemperatureControls(17th–UseofsafetyAHistoryofControlSystemsSpeedAHistoryofControlSystemsSpeedControl(18th–Wind-Millspeedcontrolbyadjustingthepitchoftheblades.Watt’sflywheelAHistoryofControlSystemsAHistoryofControlSystemsStability(19th–FormalizationofcontroltheorybyJCMaxwell,Routh(Routh-Hurwitz),AlexanderLyapunov,Bessemer(stabilizationofships)AHistoryofControlSystemsCurrentControlAHistoryofControlSystemsCurrentControlTheory(20th–DuringWorldwar2,problemofshipstabilization&gunturretpositioningwassolvedbyusingcontroltheory.ItwasreferredtoasTheoryofModerndaycontroldesignisattributedtoNicholoasMinorskywhointroducedPID(Proportional,Integral&Differential)controlInthe20’s&30’sBode&Nyquistdeveloptheanalysis&designInthelate40’sEvansdevelopedthetechniqueofRootLocusmethodofanalysis&design.ThecontrolrequirementsofspacevehiclesgavebirthtotheState-Space––––AHistoryofControlSystems1940AHistoryofControlSystems1940–1960sawthedevelopmentofclassicalcontroltheoryworkinginthefrequencydomain––––TheoryofservomechanismsNyquistStabilityCriterionBodePlotRootLocus75–80%oftheindustrialcontrolproblemscanbesolvedbyusingtheclassicalcontroltheory(FocusofthisSystemOpen-loopClosed-loop(feedbackcontrol)SystemOpen-loopClosed-loop(feedbackcontrol)Whatisopen-loopsystemandclosed-loopLetuslookatasimpleexample.PleasecomparethedifferenceClosedroomwithafan-forcedelectricCentralair-conditioningsystemwiththermostatSystemConfigurations:Open-Loop–TheopenloopcontrolsystemSystemConfigurations:Open-Loop–Theopenloopcontrolsystemisanon-feedbacksysteminwhichthecontrolinputtothesystemisdeterminedusingonlythecurrentstateofthesystemandamodelofthesystem.Thereisnofeedbacktodetermineifthesystemisachievingthedesiredoutputbasedonthereferenceinputorsetpoint.Thesystemdoesnotobserveitselftocorrectitselfand,assuch,ismorepronetoerrorsandcannotcompensatefordisturbancestothesystem.SystemConfigurations:Closed-Loop–TheclosedloopcontrolsystemisSystemConfigurations:Closed-Loop–TheclosedloopcontrolsystemisasystemwheretheactualbehaviorofthesystemissensedandthenfedbacktothecontrollerandmixedwiththereferenceordesiredstateofthesystemtoadjustthesystemtoitsdesiredSystemConfigurations:BlockDiagramsforSystemConfigurations:BlockDiagramsforOpen-LoopandClosedLoopSystemsFeedbackSystemConfigurations:AdvantagesandSystemConfigurations:AdvantagesandClosed-LoopOpen-LoopCancompensateforHighSimpleSensitivetoLessAnalysisandDesignAnalysisisAnalysisandDesignAnalysisistheprocessbywhichasystem’sperformanceisDesignistheprocessbywhichasystem’sperformanceiscreatedorchanged.Acontrolsystemisdynamic:Itrespondstoaninputbyundergoingatransientresponsebeforereachingasteady-stateresponsethatgenerallyresemblestheinput.–––ProducingthedesiredtransientresponseReducingsteady-stateerrorAnalysisandDesignObjectives:TransientAnalysisandDesignObjectives:TransientGoodTransientResponse:Gettothedesiredresponsequicklyandsmoothly.Discdrive’sread/writeheadjumpsfromonetracktoanotherAnalysisandDesignObjectives:Steady-StateAnalysisandDesignObjectives:Steady-StateLowSteadyStateError:GettothedesiredDiscdrivefinallystoppedatthecorrectAnalysisandDesignObjectives:DiscussionAnalysisandDesignObjectives:Discussionoftransientresponseandsteady-stateerrorismootifthesystemdoesnothavestability.Totalresponse=Naturalresponse+ForcedNaturalresponsedescribedthewaythesystemdissipatesoracquiresenergy.Itisdependentonlyonthesystem,nottheinputForcedresponseisdependentontheForacontrolsystemtobestable,thenaturalresponseEventuallyapproachzero,thusleavingonlytheforcedOrAnalysisandDesignObjectives:OtherAnalysisandDesignObjectives:OtherFactorsaffectinghardwareRobustTheDesignStep1:TransformTheDesignStep1:TransformRequirementsintoaPhysicalStep2:DrawaFunction