自动化专业毕业论文外文文献翻译.docx

自动化专业毕业论文外文文献翻译.docx

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自动化专业毕业论文外文文献翻译

Part1PIDtypefuzzycontrollerandparametersadaptivemethod........1Part2Applicationofselfadaptationfuzzy-PIDcontrolformainsteam

temperaturecontrolsysteminpowerstation错误～未定义书签。

7

Part3Neuro-fuzzygeneralizedpredictivecontrolofboilersteam

temperature..................................................................………13

Part4为Part3译文:

锅炉蒸汽温度模糊神经网络的广义预测控制21

Part1PIDtypefuzzycontrollerandParameters

adaptivemethod

WuzhiQIAO,MasaharuMizumoto

Abstract:

Theauthorsofthispapertrytoanalyzethedynamicbehavioroftheproduct-sumcrisptypefuzzycontroller,revealingthatthistypeoffuzzycontrollerbehavesapproximatelylikeaPDcontrollerthatmayyieldsteady-stateerrorforthecontrolsystem.ByrelatingtotheconventionalPIDcontroltheory,weproposeanewfuzzycontrollerstructure,namelyPIDtypefuzzycontrollerwhichretainsthecharacteristicssimilartotheconventionalPIDcontroller.Inordertoimprovefurthertheperformanceofthefuzzycontroller,weworkoutamethodtotunetheparametersofthePIDtypefuzzycontrolleronline,producingaparameteradaptivefuzzycontroller.Simulationexperimentsaremadetodemonstratethefineperformanceofthesenovelfuzzycontrollerstructures.

Keywords:

Fuzzycontroller;PIDcontrol;Adaptivecontrol

1.Introduction

Amongvariousinferencemethodsusedinthefuzzycontrollerfoundinliteratures,themostwidelyusedonesinpracticearetheMamdanimethodproposedbyMamdaniandhisassociateswhoadoptedtheMin-maxcompositionalruleofinferencebasedonaninterpretationofacontrolruleasaconjunctionoftheantecedentandconsequent,andtheproduct-summethodproposedbyMizumotowhosuggestedtointroducetheproductandarithmeticmeanaggregationoperatorstoreplacethelogicalAND（minimum）andOR（maximum）calculationsintheMin-maxcompositionalruleofinference.

Inthealgorithmofafuzzycontroller,thefuzzyfunctioncalculationisalsoacomplicatedandtimeconsumingtask.TagagiandSugenoproposedacrisptypemodelinwhichtheconsequentpartsofthefuzzycontrolrulesarecrispfunctionalrepresentationorcrisprealnumbersinthesimplifiedcaseinsteadoffuzzysets.Withthismodelofcrisprealnumberoutput,thefuzzysetoftheinferenceconsequencewill

1

beadiscretefuzzysetwithafinitenumberofpoints,thiscangreatlysimplifythefuzzyfunctionalgorithm.

BoththeMin-maxmethodandtheproduct-summethodareoftenappliedwiththecrispoutputmodelinamixedmanner.Especiallythemixedproduct-sumcrispmodelhasafineperformanceandthesimplestalgorithmthatisveryeasytobeimplementedinhardwaresystemandconvertedintoafuzzyneuralnetworkmodel.Inthispaper,wewilltakeaccountoftheproduct-sumcrisptypefuzzycontroller.2.PIDtypefuzzycontrollerstructure

Asillustratedinprevioussections,thePDfunctionapproximatelybehaveslikeaparametertime-varyingPDcontroller.Sincethemathematicalmodelsofmostindustrialprocesssystemsareoftype,obviouslytherewouldexistansteady-stateerroriftheyarecontrolledbythiskindoffuzzycontroller.ThischaracteristichasbeenstatedinthebriefreviewofthePIDcontrollerintheprevioussection.

Ifwewanttoeliminatethesteady-stateerrorofthecontrolsystem,wecanimaginetosubstitutetheinput（thechangerateoferrororthederivativeoferror）ofthefuzzycontrollerwiththeintegrationoferror.Thiswillresultthefuzzycontrollerbehavinglikeaparametertime-varyingPIcontroller,thusthesteady-stateerrorisexpelledbytheintegrationaction.However,aPItypefuzzycontrollerwillhaveaslowrisetimeifthePparametersarechosensmall,andhavealargeovershootifthePorIparametersarechosenlarge.Sotheremaybethetimewhenonewantstointroducenotonlytheintegrationcontrolbutthederivativecontroltothefuzzycontrolsystem,becausethederivativecontrolcanreducetheovershootofthesystem'sresponsesoastoimprovethecontrolperformance.Ofcoursethiscanberealizedbydesigningafuzzycontrollerwiththreeinputs,error,thechangerateoferrorandtheintegrationoferror.However,thesemethodswillbehardtoimplementinpracticebecauseofthedifficultyinconstructingfuzzycontrolrules.Usuallyfuzzycontrolrulesareconstructedbysummarizingthemanualcontrolexperienceofanoperatorwhohasbeencontrollingtheindustrialprocessskillfullyandsuccessfully.Theoperatorintuitivelyregulatestheexecutortocontroltheprocessbywatchingthe

2

errorandthechangerateoftheerrorbetweenthesystem'soutputandtheset-pointvalue.Itisnotthepracticefortheoperatortoobservetheintegrationoferror.Moreover,addingoneinputvariablewillgreatlyincreasethenumberofcontrolrules,theconstructingoffuzzycontrolrulesareevenmoredifficulttaskanditneedsmorecomputationefforts.HencewemaywanttodesignafuzzycontrollerthatpossessesthefinecharacteristicsofthePIDcontrollerbyusingonlytheerrorandthechangerateoferrorasitsinputs.

OnewayistohaveanintegratorseriallyconnectedtotheoutputofthefuzzycontrollerasshowninFig.1.InFig.1,andarescalingfactorsforeand~KK12

respectively,andflistheintegralconstant.Intheproceedingtext,forconvenience,wedidnotconsiderthescalingfactors.HereinFig.2,whenwelookattheneighborhoodofNODEpointinthee-~plane,itfollowsfrom

（1）thatthecontrolinputtotheplantcanbeapproximatedby

（1）

Hencethefuzzycontrollerbecomesaparametertime-varyingPIcontroller,itsequivalentproportionalcontrolandintegralcontrolcomponentsareBK2DandilK1Prespectively.WecallthisfuzzycontrollerasthePItypefuzzycontroller（PIfc）.WecanhopethatinaPItypefuzzycontrolsystem,thesteady-stateerrorbecomeszero.

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ToverifythepropertyofthePItypefuzzycontroller,wecarryoutsomesimulationexperiments.Beforepresentingthesimulation,wegiveadescriptionofthesimulationmodel.InthefuzzycontrolsystemshowninFig.3,theplantmodelisasecond-orderandtypesystemwiththefollowingtransferfunction:

K

（2）G（s）,（Ts，1）（Ts，1）12

WhereK=16,=1,and=0.5.Inoursimulationexperiments,weusetheTT12

discretesimulationmethod,theresultswouldbeslightlydifferentfromthatofacontinuoussystem,thesamplingtimeofthesystemissettobe0.1s.Forthefuzzycontroller,thefuzzysubsetsofeanddaredefinedasshowninFig.4.Theircores

ThefuzzycontrolrulesarerepresentedasTable1.Fig.5demonstratesthesimulationresultofstepresponseofthefuzzycontrolsystemwithaPlfc.Wecanseethatthesteady-stateerrorofthecontrolsystembecomeszero,butwhentheintegrationfactorflissmall,thesystem'sresponseisslow,andwhenitistoolarge,thereisahighovershootandseriousoscillation.Therefore,wemaywanttointroducethederivativecontrollawintothefuzzycontrollertoovercometheovershootandinstability.WeproposeacontrollerstructurethatsimplyconnectsthePDtypeandthePItypefuzzycontrollertogetherinparallel.WehavetheequivalentstructureofthatbyconnectingaPIdevicewiththebasicfuzzycontrollerseriallyasshowninFig.6.Where~istheweightonPDtypefuzzycontrollerandfiisthatonPItypefuzzycontroller,thelargera/fimeansmoreemphasisonthederivativecontrolandlessemphasisontheintegrationcontrol,andviceversa.Itfollowsfrom（7）thattheoutputofthefuzzycontrolleris

（3）

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3.Theparameteradaptivemethod

Thusthefuzzycontrollerbehaveslikeatime-varyingPIDcontroller,itsequivalentproportionalcontrol,integralcontrolandderivativecontrolcomponentsarerespectively.WecallthisnewcontrollerstructureaPIDtypefuzzycontroller（PIDfc）.Figs.7and8arethesimulationresultsofthesystem'sstepresponseofsuchcontrolsystem.Theinfluenceof~andfltothesystemperformanceisillustrated.When~>0and/3=0,meaningthatthefuzzycontrollerbehaveslikePDfc,thereexistasteady-stateerror.When~=0andfl>0,meaningthatthefuzzycontrollerbehaveslikeaPIfc,thesteady-stateerrorofthesystemiseliminatedbutthereisalargeovershootandseriousoscillation.

When~>0and13>0thefuzzycontrollerbecomesaPIDfc,theovershootissubstantiallyreduced.Itispossibletogetacomparativelygoodperformancebycarefullychoosingthevalueof,and.,

4.Conclusions

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Wehavestudiedtheinput-outputbehavioroftheproduct-sumcrisptypefuzzycontroller,revealingthatthistypeoffuzzycontrollerbehavesapproximatelylikeaparametertime-varyingPDcontroller.Therefore,theanalysisanddesigningofafuzzycontrolsystemcantakeadvantageoftheconventionalPIDcontroltheory.AccordingtothecoventionalPIDcontroltheory,wehavebeenabletoproposesomeimprovementmethodsforthecrisptypefuzzycontroller.

IthasbeenillustratedthatthePDtypefuzzycontrolleryieldsasteady-stateerrorforthetypesystem,thePItypefuzzycontrollercaneliminatethesteady-stateerror.Weproposedacontrollerstructure,thatcombinesthefeaturesofbothPDtypeandPItypefuzzycontroller,obtainingaPIDtypefuzzycontrollerwhichallowsthecontrolsystemtohaveafastriseandasmallovershootaswellasashortsettlingtime.

ToimprovefurthertheperformanceoftheproposedPIDtypefuzzycontroller,theauthorsdesignedaparameteradaptivefuzzycontroller.ThePIDtypefuzzycontrollercanbedecomposedintotheequivalentproportionalcontrol,integralcontrolandthederivativecontrolcomponents.Theproposedparameteradaptivefuzzycontroll