rves.Sotheidealcurvecan'tresponsetoitsactualcharacteristics.Itisinferredthatthecontrolledobjectmaybethesecond-ordercontrolledobjectthatincludeszero.ThetryanderrormethodandMATLABsimulationtoolsareusedtogetacurvewhoseparametersareclosetotheaveragedynamicparametersofthecontrolledobject'sresponsecurve.ItisshowninFig..Someadjustmentscanbemadeaccordingtothefollowingrules:)WhenthezeroisclosertotheimaginaactuatordirectlyreceivesPLCanalogyI/Oportoutput,andconvertersintofrequencyofinvertersoastodrivethe-phasemotorintheliftpump,changetheinlet,andadjusttheboilerleveltothedynamicbalanceatlast.Andtheconfigurationsoftwareisusedtodesignmonitoringpicturetorealizethecomputerandthetouchscreentotheboilerlevellong-distanceandthescenemonitoring.EstablishingMathematicsmodelforthechargedobjectOneofthemaintasksofestablishingcontrolsystemmathematicalmodelistodeterminethemathematicalmodelofthecontrolledobject.Generally,therearetwokindsofbasicmethodsforestablishingprocesscontrolmathematicalmodel:mechanismanalysisandexperimentalmethod.However,forcontrolledobjectwhosestructureandinternalprocessisverycomplex,itisverydifficulttodeterminetheobjectjustbyitsowninternalphysicalprocessandtosolveoutthedifferentialequationssystematically.Besides,consideringthenonlinearfactor,mechanismanalysisusedsomeapproximationandhypothesisformathematicaldeduction.Althoughtheseapproximationandassumptionshavepracticalbasis,butnotfullyreflectactualsituation,andevencauseincalculableeffects.Therefore,inthisdesign,theexperimentalmethodischosentoestablishamathematicalmodelforcontrolledobject.Thiskindofmodelingisbasedontheinputandoutputintheactualproductionprocess,thatistosay,establishingmathematicalmodelforthecontrolledobjectthroughprocessidentificationandparameterestimation.Inthisdesign,stepresponsecurvemethodisusedtoidentifymathematicalmodelsoftheprocess.AHzstepdisturbanceinputsignalisappliedtothechargedobject,andtheresponsecurveoftheoutputthatchangeswithtimecanbemapped.Aftertheanalysis,thetransferfunctionofthecontrolledobjectcanbedefined.Intheprocessofexperiment,theobjectwasconductedseveraltests.UsingRSLogixtrendmonitoringfunctioncurve,morethanchargedobjectstepresponsecurvehavebeenrecorded.Toalltheparametersforaverage,steadytime:ts≈.s,steadyvalue:h(∞)=.,peaktime:tp=.sovershoot:a}.Accordingtothetheoreticalanalysis,thecontrolledobjectisthemostlikelysecond-orderobject.However,thedifferenceisveryapparentbetweentheidealsecond-ordercontrolledobjectstepresponsecurveandtheactualcurves.Sotheidealcurvecan'tresponsetoitsactualcharacteristics.Itisinferredthatthecontrolledobjectmaybethesecond-ordercontrolledobjectthatincludeszero.ThetryanderrormethodandMATLABsimulationtoolsareusedtogetacurvewhoseparametersareclosetotheaveragedynamicparametersofthecontrolledobject'sresponsecurve.ItisshowninFig..Someadjustmentscanbemadeaccordingtothefollowingrules:)Whenthezeroisclosertotheimagina回路锅炉液位值调整被选定为研究对象。该系统组成如图。图锅炉水位设定值调节系统变频器作为执行机构设计,直接接收PLC类比I/O端口输出,并转换成使变频器频率带动扬程水泵三相电机,改变进气口,锅炉水位调整到在最后动态平衡。和配置软件用于监控画面设计,以实现计算机和触摸屏锅炉水位长途和现场监测。建立被控对象数学模型建立控制系统数学模型主要任务之一是确定被控对象数学模型。一般来说,建立过程控制数学模型基本方法有两种:机理分析与实验方法。然而,为控制对象,其结构和内部流程是非常复杂,它是很难确定对象,只是通过自身内部物理过程,并解决了系统微分方程。此外,考虑非线性因素,分析机制,用一些数学推导近似和假设。虽然这些近似和假设有实践基础,但不能完全反映实际情况,甚至造成不可估量影响。因此,在本设计中,选择实验方法建立被控对象数学模型。这种造型基础上,在实际生产过程中,也就是说,建立数学模型为控制对象,通过过程识别和参数估计输入和输出。在这个设计中,阶跃响应曲线法用于识别过程数学模型。Hz阶跃扰动输入信号施加到被控对象,并且,随着时间变化可以映射输出响应曲线。经过分析,控制对象传递函数可以被定义。在实验过程中,对象进行了多次测试。使用RSLogix趋势监测功能曲线,多个被控对象阶跃响应曲线已被记录。平均,稳定时间,所有参数:TS≈.s,稳定值:H(∞)=.,高峰时间:TP=.s超调量:σ≈。根据理论分析,控制对象是最有可能二阶对象。然而,区别是非常明显理想二阶被控对象阶跃响应曲线和实际曲线之间。所以理想曲线不能反应其实际特点。据推断,控制对象可能是第二阶控制对象,其中包括零。尝试和错误方法和MATLAB仿真工具,用于获取曲线参数接近被控对象响应曲线平均动态参数。如图所示可根据以下规则做一些调整:)当零接近虚轴,稳定时间将更长,冲会更大,高峰时间会更小。与零闭幕虚轴,效果更明显。)闭环主导根尖动态性能影响是增加高峰时间,减少超调量和调整时间。非参数模型来描述受控对象。换句话说,其中约描述受控对象阶跃响应曲线是由于控制对象复杂性和不确定性。安装控制器参数.控制算法选择近似被控对象数学模型建立后,形成一个完整反馈控制系统,可以提高开环控制系统性能。PID是一个理想控制律,积分引入比例,这可以消除残差,加上衍生行动,这也提高了系统稳定性基础。根据控制对象特点和实验室条件下,建立一个单一闭环反馈控制回路为控制对象,PID算法用于实现锅炉水位控制。水平控制示意图如图在一定程度上打开出口阀,使液压放电不变。水位在给定体积反馈比较过程变量,可以得到偏差。PID指令PID运算上偏差,其结果是控制变量,因此可以改变变频器频率来控制泵转速。如果液面偏高,结果使控制变量较小,流入率降低,使液面降低,如果是偏低水平上,结果使控制变量较大,增加流入率,高液位。.PID参数整定由于控制对象传递函数包括一个零二阶环节,计算工作负荷相当大,无论在理论方法使用时调整PID参数根轨迹法,频率特性法。和过程数学模型只能反映动态参数约,所以这是由理论计算得到参数值可靠性并不十分准确,将在现场不断调整。因此,工程参数优化选择,以寻求在设计PID参数。工程优化常用方法是动态特性参数,稳定边界法,衰减曲线法和外地经验,设置方法等,在PID参数过程中,:衰减曲线法通过。步骤如下:)在封闭系统中,调节器积分时间设定最大(TI≈∞)和微分时间TD设置为零(TD=)。比例巨大价值,多次执行给定值扰动实验,这一比例将逐渐减少,直到记录曲线呈现到:削弱。然后,这一比例称为:削弱比例σS两个相邻波峰之间距离被称为阻尼周期Ts。在实验中,水平定量检测为mm,然后得到系统响应曲线和重组:衰减曲线(粗红线图测量:δS≈,TS≈.;)根据下面公式,每个参数监管δ=.,δS≈.;TI=.,TS≈.;TD=.,TS≈.;)根据这些结果,调节参数设置。然后观察系统动态过程和参数作出调整,以确定最佳工艺参数。监测设计罗克韦尔自动化公司RSView软件和PanelBuilder软件分别用于显示器屏幕设计完成动画显示,参数设置,报表输出,电流曲线显示,历史曲线显示等功能。电脑和触摸屏实现远程和现场锅炉液位控制。系统监视器图像画面如图所示实现配置主要工作是建立水位控制对象,使动画显示场景。控制对象包括,inletting水流量,出口水流量和锅炉水位数值对象。当动画建立连接后,被称为基本图形元素和动画元件库在用户窗口,以构建配置图。由国家定义图形对象和数据对象设置相应属性和动画连接状态定义。在完成设计开发系统,您可以切换到运行模式进行实时监测,控制系统和测试配置。结论本文介绍了基于数学模型建立控制对象PID参数整定PLC控制,ControlLogixEFPT过程控制系统组成和运行。组态软件使用扩展通信功能。通过实验测试,控制曲线超调小,过渡时间短,所以控制效果是比较理想。这是可靠和直观设备是适用于科研和教学,并在实际工业生产中具有重要应用价值。actuatordirectlyreceivesPLCanalogyI/Oportoutput,andconvertersintofrequencyofinvertersoastodrivethe-phasemotorintheliftpump,changetheinlet,andadjusttheboilerleveltothedynamicbalanceatlast.Andtheconfigurationsoftwareisusedtodesignmonitoringpicturetorealizethecomputerandthetouchscreentotheboilerlevellong-distanceandthescenemonitoring.EstablishingMathematicsmodelforthechargedobjectOneofthemaintasksofe中文字BoilerlevelcontrolsystembasedonControlLogixPLCAbstract-ThispaperisaresearchdesignbasedonEFPTprocesscontroldevice.Inthedesign,actualindustryfieldhasbeensimulatedandcorrespondingmodelinghasbeencarriedonfortheboilerlevelsystem.ThentheappropriatePIDparameterhasbeensortedoutandControlLogiaPLChasbeenusedtocontroltheentireboilerlevelsystem.Atlast,acorrespondingcontrolinterfacehasbeenestablishedandtheboilerlevelhasbeenunderasafeandaccuratecontrolKeywords:EFPT,PID,Modeling,Boilerlevel;IntroductionThetaskoftheindustrialboilerlevelcontrolistomaintainadynamicbalancebycontrollingthewaterflowandevaporation,sothatthedrumlevelcanbemaintainedinthetechnologicallevel,whichisanecessityforensuringsafeoperationandalsooneofthemainindicatorsoftheboiler'snormaloperation.Waterlevelwhichistoohighwillaffecttheeffectofthesteam-waterseparation,buttoolowitiswillbreakringcycleorevencauseboilerexplosion.Toensureasafeandefficientproduction,theboilerlevelmustbestrictlycontrolledinmaintainingconstantorchangingonlyaccordingtoacertainrule.UsingLogixPLCwithanalogyI/Omodules,launchedbyRockwellAutomationCompanyascontrollers,andEFPTprocesscontrolexperimentaldeviceascontrolobject,thissystemhavebroughttheboilerwaterlevelunderanaccuratecontrolinaminiboilersystemwithsensorsandactuatorsthatusedinindustrialproduction.Fig.BoilerlevelsettingvalueadjustmentsystemSystemOverviewThissystemiscomposedofanEFPTprocesscontroldevice,aninverter,aLogixPLCandacomputer.EFPTprocesscontroldeviceisasimulatedheatingandwatersupplyanddrainagesystemforamicro-smallboiler.Itrealizesprocesscontrolinaminiboilersystemwithsensorsandactuatorsusedinindustrialproduction.Theactuatorincludesnotonlymeasuringappliance,butalsoACinverter,heatingcontroller,heaterandsoon.Thesystemsimulatesindustryscenethroughamini-boilerheating,watersupplyanddrainagesystem,whichisreliableandvisual.Inthedesign,boilerLevelwasselectedasthecontrolledvariable.Thecontrolledobjectiscomposedofthewatertrough,theforcepump,theboilerandthepipe-linevalve.MicroMasterSE-ODAinverteristakenastheactuatorandtheboilerleveliscontrolledbyLogix.ConfigurationsoftwareRSViewandtouchscreenPanelViewarecombinedtorealizethereal-timemonitoring.Inthedesign,asimpledesignofsingle-loopboilerliquidlevelvalueadjustmentisselectedforthestudy.ThecompositionofthesystemisshowninFig..Inthedesign,theinverterasanactuatordirectlyreceivesPLCanalogyI/Oportoutput,andconvertersintofrequencyofinvertersoastodrivethe-phasemotorintheliftpump,changetheinlet,andadjusttheboilerleveltothedynamicbalanceatlast.Andtheconfigurationsoftwareisusedtodesignmonitoringpicturetorealizethecomputerandthetouchscreentotheboilerlevellong-distanceandthescenemonitoring.EstablishingMathematicsmodelforthechargedobjectOneofthemaintasksofestablishingcontrolsystemmathematicalmodelistodeterminethemathematicalmodelofthecontrolledobject.Generally,therearetwokindsofbasicmethodsforestablishingprocesscontrolmathematicalmodel:mechanismanalysisandexperimentalmethod.However,forcontrolledobjectwhosestructureandinternalprocessisverycomplex,itisverydifficulttodeterminetheobjectjustbyitsowninternalphysicalprocessandtosolveoutthedifferentialequationssystematically.Besides,consideringthenonlinearfactor,mechanismanalysisusedsomeapproximationandhypothesisformathematicaldeduction.Althoughtheseapproximationandassumptionshavepracticalbasis,butnotfullyreflectactualsituation,andevencauseincalculableeffects.Therefore,inthisdesign,theexperimentalmethodischosentoestablishamathematicalmodelforcontrolledobject.Thiskindofmodelingisbasedontheinputandoutputintheactualproductionprocess,thatistosay,establishingmathematicalmodelforthecontrolledobjectthroughprocessidentificationandparameterestimation.Inthisdesign,stepresponsecurvemethodisusedtoidentifymathematicalmodelsoftheprocess.AHzstepdisturbanceinputsignalisappliedtothechargedobject,andtheresponsecurveoftheoutputthatchangeswithtimecanbemapped.Aftertheanalysis,thetransferfunctionofthecontrolledobjectcanbedefined.Intheprocessofexperiment,theobject 1中文2710字BoilerlevelcontrolsystembasedonControlLogix5550PLCAbstract-ThispaperisaresearchdesignbasedonEFPTprocesscontroldevice.Inthedesign,actualindustryfieldhasbeensimulatedandcorrespondingmodelinghasbeencarriedonfortheboilerlevelsystem.ThentheappropriatePIDparameterhasbeensortedoutandControlLogia5550PLChasbeenusedtocontroltheentireboilerlevelsystem.A