资源描述：
《A two degree of freedom level control 》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、JournalofProcessControl11(2001)311±319www.elsevier.com/locate/jprocontAtwodegreeoffreedomlevelcontrolKwo-LiangWu,Cheng-ChingYu*,Yu-ChangChengDepartmentofChemicalEngineering,NationalTaiwanUniversityofScienceandTechnology,Taipei,Taiwan106,ROCAbstractAtwodegreeoffreedomcontrolisproposedforl
2、iquidlevelcontrol.Theloadestimationisachievedinanindirectmanner.Onlyonedesignparameterisrequiredfortheloadestimation.Asforthefeedbackloop,aP-onlyfeedbackactionisemployed.ItisequivalenttoaPcontrolatdisturbancefreeconditionandbecomesaPIcontrollerunderloaddisturbance.Steady-statechar-acteri
3、stics,dynamicpropertiesandrobustnessissuesareexplored.Designproceduresarealsoproposed.Asurgetankexampleisusedtoillustratetheperformanceoftheproposedcontrol.Theresultsshowthatthetwo-degreeoffreedomcontrolgivesgoodnominalperformanceandisrobustwithrespecttomodelingerrors.Improvedperformance
4、arealsoobservedforsystemswithtimedelayorright-half-planezero.#2001ElsevierScienceLtd.Allrightsreserved.Keywords:Levelcontrol;Loadestimation;Twodegreeoffreedomcontrol1.IntroductionSincetheintroductionofthe``integratorplusdead-time''formtorepresentslowchemicalprocesses[7],Controlofliquidle
5、velinvolvestwocon¯ictingcon-workshavebeendonetostudytuning[8],autotuningsiderations.First,changesinoutlet¯owratesshouldbeanddead-timecompensation[9,10]aspectsofintegratorassmoothaspossible.Second,levelshouldnotbeper-plusdead-timeprocesses.HangandWong[11]andlatermittedtodeviatetoofarfromn
6、ominalliquidlevel.ThisAÊstroÈmetal.[9]proposeanewformofSmithpredictoristheproblemofaveraginglevelcontrol.Inapioneer-whereloaddisturbanceisestimatedand,subsequently,ingwork,LuybenandBuckley[1]proposeafeed-compensated.MatausekandMicic[10]giveagoodforward/feedbackcon®gurationforlevelcontrol
7、:descriptionofthemodi®edSmithpredictor.Again,theproportional-lag(PL)control.InPLcontrol,thepro-modi®edSmithpredictorutilizesthecharacteristicofportionalcontrolbasedfeedbackloopprovides¯owintegratorprocesstoprovideoset-freeloadestimation.smoothingwhilethefeedforwardcompens
