简介：Anadaptiveactuatorfailurecompensationschemeisproposedforattitudetrackingcontrolofspacecraftwithunknowndisturbancesanduncertainactuatorfailures.Anewfeatureofthisadaptivecontrolschemeistheadaptationofthefailurepatternparameterestimates,aswellasthefailuresignalparameterestimates,fordirectadaptiveactuatorfailurecompensation.Basedonanadaptivebacksteppingcontroldesign,theestimatesofthedisturbanceparametersareusedtosolvethedisturbancerejectionproblem.Theunknowndisturbancesarecompensatedcompletelywiththestabilityofthewholeclosed-loopsystem.Theschemeisnotonlyabletoaccommodateuncertainactuatorfailures,butalsorobustagainstunknownexternaldisturbances.Simulationresultsverifythedesiredadaptiveactuatorfailurecompensationperformance.

简介：Therobustboundedflightcontrolschemeisdevelopedfortheuncertainlongitudinalflightdynamicsofthefighterwithcontrolinputsaturationinvokingthebacksteppingtechnique.Toenhancethedisturbancerejectionabilityoftherobustflightcontrolforfighters,theslidingmodedisturbanceobserverisdesignedtoestimatethecompoundeddisturbanceincludingtheunknownexternaldisturbanceandtheeffectofthecontrolinputsaturation.Basedonthebacksteppingtechniqueandthecompoundeddisturbanceestimatedoutput,therobustboundedflightcontrolschemeisproposedforthefighterwiththeunknownexternaldisturbanceandthecontrolinputsaturation.Theclosed-loopsystemstabilityunderthedevelopedrobustboundedflightcontrolschemeisrigorouslyprovedusingtheLyapunovmethodandtheuniformlyasymptoticalconvergencesofallclosed-loopsignalsareguaranteed.Finally,simulationresultsarepresentedtoshowtheeffectivenessoftheproposedrobustboundedflightcontrolschemefortheuncertainlongitudinalflightdynamicsofthefighter.

简介：Reactioncontrolsystem(RCS)isapowerfulandefficientactuatorforspacevehiclesattitudecontrol,whichistypicallycharacterizedasapulsedunilateraleffectoronlywithtwostates(off/on).Alongwithinevitableinternaluncertaintiesandexternaldisturbancesinpractice,thisinherentnonlinearcharacteralwayshindersspacevehiclesautopilotfrompursuingprecisetrackingperformance.Comparedtomostofpre-existingmethodologiesthatpassivelysuppresstheuncertaintiesanddisturbances,adesignbasedonpredictivefunctionalcontrol(PFC)andgeneralizedextendedstateobserver(GESO)isfirstlyproposedforthree-axisRCScontrolsystemtoactivelyrejectthatwithnorequirementforadditionalfuelconsumption.ToobtainahighfidelitypredictivemodelonwhichtheperformanceofPFCgreatlydepends,thenonlinearcouplingmultiple-inputmultiple-output(MIMO)flightdynamicsmodelisparameterizedasastate-dependentcoefficientform.Andbasedonthat,aMIMOPFCalgorithminstatespacedomainforaplantofarbitraryordersisdeducedinthispaper.Theinternaluncertaintiesandexternaldisturbancesarelumpedasatotaldisturbance,whichisestimatedandcancelledtimelytofurtherenhancetherobustness.Thecontinuouscontrolcommandsynthesisedbyabovecontroller-rejectortandemisfinallymodulatedbypulsewidthpulsefrequencymodulator(PWPF)toon-offsignalstomeetRCSrequirement.Therobustnessandfeasibilityoftheproposeddesignarevalidatedbyaseriesofperformancecomparisonsimulationswithsomeprominentmethodsinthepresenceofsignificantperturbationsanddisturbances,aswellasmeasurementnoise.

简介：Anadaptivefuzzyslidingmodecontrol(AFSMC)approachisproposedforaroboticairship.First,themathematicalmodelofanairshipisderivedintheformofanonlinearcontrolsystem.Second,anAFSMCapproachisproposedtodesigntheattitudecontrolsystemofairship,andtheglobalstabilityoftheclosed-loopsystemisprovedbyusingtheLyapunovstabilitytheorem.Finally,simulationresultsverifytheeffectivenessandrobustnessoftheproposedcontrolapproachinthepresenceofmodeluncertaintiesandexternaldisturbances.

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