強反作用下挖泥船動力定位自適應(yīng)反步控制

強反作用下挖泥船動力定位自適應(yīng)反步控制

dr.dr.運行的區(qū)域和緩慢運行的特征。dps是一個非常高的損壞率。就像這類錯誤一樣，可以采取主動的措施，以確保數(shù)據(jù)收集的質(zhì)量，并將數(shù)據(jù)收集系統(tǒng)的數(shù)量轉(zhuǎn)移到所有悲傷的評估中。要求是so非正義線人，壓力和跟蹤機(jī)制是應(yīng)用程序，而不是線人。這是基本的?？蚣軈f(xié)議的操作是可靠的。本線無線電話系統(tǒng)應(yīng)該是有效的。Adynamicallypositionedvesselmaintainsitsposition(fixedlocationorpredeterminedtrack)exclusivelybymeansofactivethrusters.However,inaconventionalchainandanchormooringsystem,thelengthoflinesbecomesexcessivesothatmaintainingthepositionofanoffshoreplatformbecomesdifficultbothtechnicallyandeconomically.Therefore,DPsystemswiththrustersareoftenusedforthoseapplications.ThefirstDPsystemwasintroducedintheearly1960s.TheconventionalDPsystemsarebasedonthelinearizedsystemwhichiswidelyusedintheDPsystemsforships.Becauseofthelimitationsoflinearcontroltechniques,suchascomplexityintuningcontrolgainsandnoglobalstabilityresultsduetolinearization,recently,someresearchershaveappliedthenonlinearcontroltheorytodesigncontrolsystemsfortheDPofthesurfacevessels.Krsticetal.developedabacksteppingapproachofastep-bystepdesignprocedure.TheLyapunovtechniqueandthebacksteppingtechniqueareusedtodesignaDPcontrollersystem.Recently,theadaptivebacksteppingtechniqueshavedevelopedrapidly.Inthispaper,theadaptivebacksteppingmethodisusedinthedredgerDPS.Theadaptivemethodcanestimatethevalueofdisturbancesandchangethefeedbacktoguaranteestability.ComparisonsarecarriedouttoverifytheadvantagesoftheadaptivebacksteppingtechniqueovertheconventionalbacksteppingcontroltechniqueinthedredgerDPS.1aswwell因子First,asymmetricalxz-planeisdefinedtodescribetheproblem,wherethez-axispointstothegeocentric.AsshowninFig.1,OEXEYEistheearth-fixedframe,OXYisthebodyfixedframe,andOcisthecenterofgravityofthevessel.Assumethatthefollowingconditionshold:2)Thesurgeisdecoupledfromsway,yawandheave;3)Thepitchandrollmodesareignored;4)Thebody-fixedframecoordinateoriginisonthecentre-lineoftheship(seeFig.1).ThemathematicalmodeloftheshipusedfortheDPinahorizontalplaneisdescribedaswhereτdisrepresentstheenvironmentaldisturbances;η=[xyψ]Tdenotestheposition(x,y)andheadingψo(hù)ftheshipcoordinatedintheearth-fixedframe;v=[uwr]Tindicatesthesurge,swayandyawvelocitiesoftheshipcoordinatedinthebody-fixedframe.TherotationmatrixJ(ψ),themassmatrixM,andthedampingmatrixDaregivenbywheremisthevesselmass;Izisthemomentofinertiaaboutthebody-fixedz-axis;xgisthedistancefromtheoriginOofthebody-fixedframetothecenterofgravityofthevessel.TheothersymbolscanbereferredtoRef..Thecontrolinputvectorτ∈R3offorcesandmomentsprovidedbytheactuatorsystem,andthedisturbancevectorτdisofforcesandmomentsinducedbywaves,windandoceancurrentsaregivenbywhereh∈Rnisthecontrolinputwithn≥3denotingthenumberofindependentactuators,andG∈R3×nisaconstantmatrixdescribingtheactuatorconfiguration.Unmoldedexternalforcesandmomentsduetowaves,wind,oceancurrents,andshipparametersperturbationarelumpedtogetherintoanearth-fixedconstantvectorb∈R3.Tosimulatethemarineenvironmentdisturbance,thefollowingmodelisadopted.Theenvironmentalforcemodelinthefixedcoordinatesystemiswherebisathree-dimensionalvector;Tisathree-dimensionaltime-constantdiagonalmatrix;ωbisazero-meanwhitenoisevector;andEbisathree-dimensionaldiagonalmatrixwhichdenotestheamplitudeoftheenvironmentalforces.Theprobleminthispaperistodesignarobustadaptivebacksteppingcontrollerτofsystem(1),whichmakestheoutputηasymptoticallytrackitsreferencesignal.2出plagere號,出p1.3.4indeivatch/wearge-lager.3.4.3indexh-lahenge/wssinficienratchs..4sindexh-lahens.....................................................5.5Thetwo-steprealizationprocessofthecontrollerisderivedinthissection.Step1ηdisdefinedasthedesiredposition,thenthepositionerrorisThederivativeofe1isTakevasavirtualcontroller,thenanewerrorisdefinedaswherea1isastabilizingfunctionwhichwillbedesignedlater.SelectthefirstLyapunovfunctioncandidateasThenthetimederivativeofV1canbeobtainedasTakethefirststabilizingfunctiona1asSubstitutingEq.(8)intoEq.(7),wecanobtainStep2AccordingtoEq.(5),thederivativeofe2isMultiplyingbothsidesofEq.(10)byM,weobtainSubstitutingEq.(1)intoEq.(11)resultsinSelectthesecondLyapunovfunctioncandidateaswhereρ=diag{λ11,λ22,λ33}istheadaptivegaincoefficientmatrix,SubstitutingEqs.(9),(10)and(12)intoEq.(14),weobtainAccordingtoEq.(8),thederivativeofa1isBysubstitutingEq.(16)intoEq.(15),Eq.(15)istransformedintoLettheactualcontrolτbeLetthedisturbancesadaptiveupdatinglawbeSubstitutingEqs.(18)and(19)intoEq.(17),wecanobtainSubstitutingEq.(20)intoEq.(21),weobtainAsK1>0andK2>0areselected,thesystem(1)isgloballyasymptoticallystable.3u2004上的lawellingpolicy-axissiphengacinpen,siqTheperformanceoftheclosed-loopDPsystemisdemonstratedbysimulationsusingtheMatlab/Simulinktoolbox.ThemaindimensionsoftheexampleshiparegiveninTab.1.BasedonthemainparameterslistedinTab.1,thenondimensionalsystemmatricesdescribingtheshipareestimatedbytheempiricalformulaasTheadaptivebacksteppingcontrollerparametersareselectedasK1=diag{2,2,2},K2=diag{2,2,2},andρ=diag{5,5,5}insimulations.Thestartpositionoftheshipis[000]T.Thetraditionalandadaptivebacksteppingcontroltechniquesarecomparedwitheachother.Especiallylargedisturbancessuchasharshseaconditionsorthereactionforcesofdredgingareconsideredtodemonstratetherobustperformanceofthecontroller.AccordingtoEq.(2),theparametersdescribinglargedisturbancesaresetasfollows:Therearetwotypesofdisturbancesinthissection.Oneisthelargeamplituderepresentingtheharshseaconditionsandtheotheristhedramaticchangerepresentingdredgingoperations.ThemaximumvaluesofdisturbancesarelistedinTab.2,andthey-axisdisturbancewaveformanditsadaptivevaluewaveforminadaptivebacksteppingareshowninFig.2,andoutputssteady-stateerrorsofbacksteppingandadaptivebacksteppingarelistedinTab.3.Simulationresults(y-axis)ofthetraditionalandadaptivebacksteppingtechniquesareshowninFig.3andFig.4,respectively.Simulationresultsshowverysimilarperformanceinthex-axis,yawandy-axisbehaviours.Bothapproachescanmaintainstabilityinthepresenceofdisturbances.However,theadaptiveonecanobtainbetterperformance.Thisisbecausetheadaptivealgorithmcanestimatethedisturbancesandmakecompensationaccurately.4siphingsiphingsiphinficidicidicidingsiphingsiphing.siphing.siphing.siphing.siphing.siphing.sivietBasedonthepertu