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自动控制装置仪表论文（Automaticcontroldevice,instrument,thesis）DOCdocumentsmayexperiencepoorbrowsingontheWAPside.ItisrecommendedthatyoufirstselectTXT,ordownloadthesourcefiletothelocalview.Introduction:openloopcontrolsystemstructureandcontrolissimple,anti-interferenceability,lowcontrolprecision,isgenerallyusedtocontrolperformancerequirementsoftheoccasion,thegreenhouseautomaticcontrolsystemisaclosed-loopcontrolsystemconsistsofC51microcontroller,A/Dconversioncircuit,temperaturedetectioncircuit,humiditydetectioncircuitandcontrolsystem.Thetemperaturedetectioncircuitwilldetectthetemperatureintothevoltage,theanalogvoltageisconvertedintoC51,MCU,MCUbycomparingtheinputtemperatureandthesettemperaturetocontrolthefanorelectricdrivecircuit,whentheindoortemperaturewithinthepresetrange,SCMwrongsprinklerorelectricactionmadeby.Theindoortemperatureandairhumidityaredetected,monitored,andthetemperatureandhumidityrangecanbetreatedinrealtime,sothattheindoorenvironmentiswellcontrolled.PrincipleofproportionalcalculuscontrolPIDcontrolalgorithmissimple,stableandreliable.Itiswidelyusedinprocesscontrolandmotioncontrol,especiallyfordeterministicsystemswhichcanestablishaccuratemathematicalmodel. Proportionalintegralregulator(PD)1.1proportionalintegralregulator(PD)Theproportionalregulatorhastheerror.Inordertosolvethisproblem,theintegrallinkcanbeintroduced,andtheproportionaldifferentialregulatorcanproduceacontrolactionratiotoanychangeoftheerror,whichcanpreventthechangeoftheerror.ThefastertheCchanges,thegreaterthePD,andthegreatertheoutputcorrection.Ithelpstoreduceovershoot,overcomeoscillations,stabilizethesystem,speeduptheresponseofthesystemandreducetheadjustmenttime,thusimprovingthedynamiccharacteristicsofthesystem.Itsdisadvantageisitspooranti-interferenceability.1.2PIDregulatorTheintegratorcaneliminatetheerrorandimprovetheprecision,buttheresponsespeedofthesystemisslowandthestabilityisworse.Thedifferentiatorincreasesstabilityandspeedsupresponse.Thescaleisthebasiclink.Thecombinationofthethreeandtheselectionofappropriateparameterscanachievestablecontrol.TheconventionalPIDregulatorisalinearregulator,andfigure1.1isablockdiagramofthePIDregulator.Fig.1.1thestructurediagramoftheconventionalPIDregulator.ThePIDcontrollermakestheratioofthedeviation(P),theintegral(I)andthedifferential(D)alinearcombinationtocontrolthequantity,andcontrolsthecontrolledobject.Thecontrolformulaisasfollows. One1tde(T)??U(T)=Ke(T)+e(T)formula+Td0?TiDT??Formula:Kpistheproportionalityfactor,Tiistheintegraltimeconstant,andTdisthedifferentialtimeconstant.Simplyspeaking,thefollowingPIDcontrollerofthecorrectionfunction:proportionalsystem:thetimelyproportiontoreflectthedeviationsignalofthecontrolsystem,thedeviationoncegenerated,controllerimmediatelyproducethecontrol,toreducethedeviation.Integralpart:integraladjustmentcanimprovetheanti-interferenceabilityofthesystem.Itismainlyusedtoeliminatestaticerrorandimprovethedegreeofnostaticdifferenceofthesystem.Itissuitableforthesystemwithselfbalance.Differentiallink:differentialloopenergysavingreflectsthechangingtrendofthedeviationsignal.Soastospeedupthemovementofthesystem,reducetheadjustmenttime,andthusimprovethedynamiccharacteristicsofthesystem.Thedisadvantageisthattheanti-interferenceabilityispoor.P???Two.RealizationmethodofautomaticcontrolsystemThecharacteristicsofallaspectsoftheautomaticcontrolsystemaregenerallygiven,suchasmechanical,pneumatic,electric,hydraulicandotherequipment.Whendesigninganautomaticcontrolsystem,thesystemcharacteristicsarechangedbyaddingalink(correction)whichisspeciallyusedtocorrect(compensate)thesystemcharacteristicssoasto meettherequirementsofthegivencharacteristics.Thedevicethatimplementsthislinkiscalledacorrectororregulator.Amajorpartoftheautomaticcontrolsystemisthecorrectiondevice.Astheopen-loopcontrolsystemisgenerallynotuptothecontrolrequirements,theautomaticcontrolsystemadoptsclosedloop(feedback)controlmethod.Whenserialcorrectionisused.+enterRegulatorControlledobjectAfeedbackFigure2.1.Thespecificimplementationstepsoftheautomaticcontrolsystemareasfollows:1.Givethecharacteristics(desiredcharacteristics)requiredbythesystem.Thesystemcomponents(suchaselectricprotection,motor,etc.)areselectedbytherequirementsofcontrolpurposeandstaticcharacteristic.Thirdly,thesystemcharacteristicsofthesystemareanalyzedandcomparedwiththedesiredcharacteristicsofthesystem,andthecorrectiondevicecharacteristicsareobtainedbycomparingtheresults.Checkthecharacteristicsofthesystemdesignedthereby,andupdatethecorrectiondeviceifnotsatisfied TwoUntilthecalibrationmeetstherequirementsasfollows:specificdesignmethods,sometimesdomainmethods,frequencymethods,androotlocusmethods.Intimedomain,thesystemisanalyzedaccordingtothemethodintroducedearlier,andtheappropriatecorrectiondeviceisselected,Tomeettherequirementsofsystemcharacteristics,steady-stateerror,overshoot,transitiontimeandsoon.Frequencymethodistoanalyzethefrequencycharacteristicsofthesystem,selecttheappropriatecorrectiondevicetochangetheshapeofitslogarithmicfrequencycharacteristics,inordertomeetthesystemsteady-stateerror,phasemarginandcut-offfrequencyrequirements.Thefrequencycharacteristicisthecomplexratiobetweentheoutputsteadycomponentofthesystemandtheinputsteadystateunderthesinusoidalinput,namelythetransferfunction.Therootlocusmethodistoanalyzethetrajectoryoftherootoftheclosedlooptransferfunction,andthenselecttheadaptivecorrectiondevicetomeettherequirementsofsystemstability,steady-stateerroranddynamicresponse.Three.Analysisofeachcomponentoftheautomatictemperaturecontrolsystem3.1temperaturesensorAtemperaturesensortransformsatemperaturesignalintoanelectriccurrentoravoltageletter.Ithasmanytypes,and thevarioustemperaturesensorshavedifferentcharacteristicsandrangesofapplication.Thethermistorthermistorisasemiconductorheatresistance,accordingtothetypicalcharacteristicsofthesemiconductorresistancevarieswithtemperature,therearethreetypesofthermistor;negativetemperaturecoefficientthermistor(NTC)andthepositivetemperaturecoefficientthermistor(PTC)andthecriticaltemperatureresistor(CTR).Thethermocoupletwodifferentconductor(orsemiconductor)AandBformaclosedloop,whenthetwocontacttemperatureA,Bphaseisnotthesame,istoproduceathermalelectromotiveforceintheloop,thisphenomenoniscalledthethermoelectriceffect.Thecombinationofthesetwodifferentconductors(orsemiconductors)iscalledathermocouple.3.2compareunitsWhenthetemperaturesignalafterconversionistransmittedtoMCU,MCUwillreceivethesignalandtemperaturesignalcomparison,drivecircuitandaccordingtotheresultsofthecomparisontocontroltheelectricfurnaceorfan,toadjustthecontroldeviceforthework,toachievethedesiredpurposeofregulatingtemperatureandhumidity.3.3executionunitTheexecutionunitiscomposedofasiliconcontrolledcircuitandacircuit,aheatingdeviceorawatersprayingdevice.Whenthedetectedtemperaturethanthepresettemperature,thecircuitcomparestotheamplifyingcircuitasignalamplifiedbytheamplifyingcircuitafterthethyristorcircuit,driving circuitandheatingdevice,whenthetemperaturerisestothesettemperaturerange,thesignalamplificationcircuitisnotsufficienttomaintaintheSCRcircuitthen,theheatingdevicestopsworking,theindoorismaintainedataconstanttemperaturerange,theworkingprincipleofhumiditycontrolandthelike.Siliconcontrolledrectifier(SCR)characteristicsiliconcontrolledbyfourlayersofsemiconductormaterial,andcanbeequivalenttotwotransistors.Ithasthreepoles,respectivelyA,G,controlofanodecathodeKofthreeelectrodes,whentheanodepotentialishigherthanthecathodepotential,gatecurrentincreasestoacertainvalue(triggercurrent),siliconcontrolledbythedeadlineforconduction,oncetheconduction,ifthegatecurrentis0.Thecontrolledsiliconremainsconduction,untiltheanodepotentialislessthanorequaltothecathodepotential,theanodecurrentislessthanthecurrentmaintenanceofcontrollablesiliconisguidedbythedeadlinechange.Four,automatictemperaturecontrolprogramThreeTheimplementationschemeisasfollows:TemperaturefeedbackTemperaturedetectingcircuitCurrentvoltageconversioncircuit Comparisoncircuit1Blockdiagramoftheamplifiercircuit4.1Siliconcontrolledcircuit1ElectricfurnaceheatingdeviceHumiditydetectingcircuitCurrentandvoltageconversioncircuit,thyristorcircuit,2waterjetdeviceComparisoncircuit2AmplifyingcircuitHumidityfeedbackblockdiagram4.2Theanalysisofworkingprincipleofthetemperaturedetectioncircuittodetecttheindoortemperature,thetemperaturesensordetectsthetemperaturewillbeconvertedtoanalogvoltagetransmittedtothecomparisoncircuitwhenthedetectedtemperatureislowerthanthesettemperature,theanalogvoltageaftertransformationandamplificationcircuitSCRtriggercircuit1conduction,electricheatingdevice,whenthetemperaturebacktothenormaltemperaturerange,thetemperaturesensorintothevoltageisnotenoughtomakethethyristorcircuit1conduction,electricheatingdeviceforheating.Theworkingprincipleofthehumiditydetectingcircuitissimilartothatofthetemperaturedetecting circuit.Five,summingupexperienceAfterasemesterof"automaticcontrolinstrumentsandequipment"courseIlearnmoreknowledgeofautomaticcontrolinstrumentintheprocessoflearning,myknowledgeofanalogcircuitagainovertheautomaticcontrolsystemoflifeeverywhere,suchasairconditioners,refrigerators,thermostats,althoughtherearemanyautomaticcontrolFourSystem,butitsownknowledgeofthecontrolsystemisstillverylittle,andtheoreticallearninghasnevercomeintocontactwithacompleteautomaticcontrolsystem.IntheprocessofwritingthispaperIcheckedalotaboutautomaticcontrolsystemofknowledge,benefit,Inotonlyfamiliarwiththeconsolidationofthepreviousknowledge,butinmanyplaceshavetheinsightandunderstandingofthenew,thetheoreticalknowledgeandpracticalcombinationoflifeitself.Duetothelimitationoftheirownknowledge,wecannotanalyzedetailedandthoroughdescriptionofacompletecontrolsystem,onlytheuseofpreviouslylearnedknowledge,throughtheexaminationofsomerelevantinformation,theprincipleofindoortemperaturecontrolsystemandtherealizationoftheprogramtodoasummaryaccount,itisawareoftheirknowledgewillspurmeconstantlyforward.Irealizedtheimportanceofautomaticcontrolsysteminlife,lifeinthefutureIwillcontinuetostrengthenthecontrolofknowledgeandlearning, payattentiontotheemergenceofnewequipment,theautomaticcontrolsysteminlifeandtheirowntheoriestocombinethislearningeffectwillbebetter,theunderstandingofknowledgewillbemoredeep.Reference[1][2][3][4][5]."Wuveryautomaticcontrolinstrumentanddevice".WuveryChemicalIndustryPress.Huacheng.English.Whitepoetry"analogcircuit".Highereducationpress.ZongXiaoping.WangXia.Principleofautomaticcontrol.ChinaMetrologypress.Designtheoryofautomaticcontrolsystem.Mechanicalindustrypress."Powerelectronictechnology"FiveOne
