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    25 December 2013, Volume 33 Issue 6 Previous Issue    Next Issue
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    ResearchonCompoundControlforSolarSailSpacecraftAttitudeManeuvering
    ZHAI Kun, ZHANG Jin, WANG Tian-Shu
    2013, 33 (6):  1-8.  doi: 10.3780/j.issn.1000-758X.2013.06.001
    Abstract ( 1715 )   PDF (406KB) ( 1566 )   Save
    Theinputshapingmethodscan′teliminateflexiblevibrationsduringtheattitudemaneuvering.Theresidualflexiblevibrationwillchangethestructureparametersofthelargeflexiblesolarsailspacecraftandinfluencethecontrolprecisionofattitudemaneuvering.Therefore,thecompoundcontrolmethodwasproposedtoeliminatetheflexiblevibrationduringtheattitudemaneuvering,basedonthecombinationoftwokindsofcontrolways.Thecouplingdynamicmodelsofsolarsailattitudemotionsandflexiblevibrationswereestablishedbythemethodoftakingthesailmembranesqualityequivalenttobooms.Consideringofreducingtheexternalforcesofvibrationmodes,twokindsofcompoundcontrolstrategieswereobtainedbythesimplifieddynamicmodels.Accordingtothesimulationresults,themaneuveringtimeofthesecondcompoundcontrolmethodisfewerthanthatoftheinputshapingmethod.Thesecondcompoundcontrolmethodcanreduceflexiblevibrationsto5%duringtheattitudemaneuveringprocessandmaketheprecisionofthemaneuveringanglebetterthan0.003°.Becauseofjustusingthoseexistedcontrolways,thealgorithmsofthecompoundcontrolmethodaresimpleandsuitabletothepracticalapplications.
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    RemoteSensingImageChangeDetectionBasedonWaveletandKernelIndependentComponentAnalysis
    WU Yi-Quan, CAO Zhao-Qing
    2013, 33 (6):  9-16.  doi: 10.3780/j.issn.1000-758X.2013.06.002
    Abstract ( 1181 )   PDF (654KB) ( 1041 )   Save
    Inordertofurtherimprovetheaccuracyofchangedetectionofremotesensingimagesbasedonindependentcomponentanalysis(ICA)andtosolvetheuncertaintyproblemofsequenceofimagecomponentsseparatedbyICA,achangedetectionmethodbasedonwavelettransformandkernelindependentcomponentanalysis(KICA)wasproposed.Firstly,theremotesensingimagesweredecomposedbywavelettransform,andpartitionedvectorscomposedofhigh-frequencycomponentsandlow-frequencycomponentswereobtained.Thenthepartitionedvectorsweremappedintoahigh-dimensionalfeaturespacebythekernelfunction,andthemutuallyindependentvectorswereseparatedbyICAinthisspace.Finally,accordingtothedifferencesbetweenthehigh-frequencycomponentsoftheseparatedvectors,thechangecomponentwasdistinguishedautomatically.Experimentalresultsoftheproposedmethodandotherthreechangedetectionmethodsproposedrecentlybasedontheprincipalcomponentanalysis(PCA),ICA,KICAweregiven.Andsomeanalysisandquantitativecomparisonsweredone.Alargenumberofexperimentalresultsshowthattheproposedmethodcanseparatechangeinformationofremotesensingimageswithhigheraccuracy,andtheintelligentchangedetectionisrealized.
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    Earth-to-MarsTransferOrbitOptimizationBasedonMeshRefinement
    GU Liang-Xian, ZHAO Ji-Song
    2013, 33 (6):  17-25.  doi: 10.3780/j.issn.1000-758X.2013.06.003
    Abstract ( 1274 )   PDF (469KB) ( 1048 )   Save
    Ageneralnonsmoothtrajectoryoptimizationapproachwaspresented.Themeshrefinementprocedurebasedondatacompressondyadicgridswasimprovedtoincreasetheefficiency,usabilityandflexibility,andwasthencombinedwiththelocalcollocationmethodwhichtookadvantageofscaling,sparsityanddifferentnumericaldifferentiationofnonlinearprogramming(NLP).NumericalsimulationonEarth-to-Marstransferorbitoptimizationdemonstratesthattheapproachcapturesnonsmoothregionsexactlywithdensitymeshandhasthepotentialofon-boardoptimization.Furthermore,theapproachcapturesnon-smoothregionsofstateseventhoughthemeshisrefinedaccordingtothecontrolvariables.ForEarth-to-Marstransferorbitoptimization,itisbettertodefinethethrustanglein[0,360°)thanthatin[-180°,180°).
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    SensorlessControlStrategyforSGCMGHighSpeedRotor
    LU Ming, TIAN Li-Mei, LI Lian-Xiang, ZHAI Bai-Chen, HU Yue-Wei
    2013, 33 (6):  26-32.  doi: 10.3780/j.issn.1000-758X.2013.06.004
    Abstract ( 1572 )   PDF (407KB) ( 1077 )   Save
    Sensorlesscontrolstrategyforrotorsystemofthesinglegimbalcontrolmomentgyro(SGCMG)couldreducecomplexityandpromotereliabilityofthewholeset.Themethodsbasedonthebackelectromotiveforce(EMF)detectionofthehalfbridgedrivebrushlessDCmotor(BLDC)andthedisturbanceeliminatingmethodswithoutlowpassfilterwereproposed,whichcouldachieveshighdetectionprecision.Forthestartupprocess,afoursegmentstrategywasproposedincludingorientationsegment,I/fstartupsegment,speedestimationstartupsegmentandswitchsegment,whichrealizedareliablestartupprocess.Simulationsandexperimentsprovetheeffectivenessoftheproposedmethod.ReliableandaccuratesensorlesssystemforSGCMGhighspeedrotorisrealized.
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    Vision-BasedRelativeNavigationforRendezvousandDockingofSpacecraft
    LIU Yong, XU Peng, XU Shi-Jie
    2013, 33 (6):  33-40.  doi: 10.3780/j.issn.1000-758X.2013.06.005
    Abstract ( 1266 )   PDF (469KB) ( 1073 )   Save
    Forthefinalphaseofspacecraftautonomousrendezvousanddocking,thevisionrelativenavigationmethodbasedontheinformationofthespecificreferencelightsourceswaspresented.Undertheassumptionofsmallattitudeangle,therelativenavigationmodelswerededuced.Theclosed-formsolutionforrelativeattitudeandpositionparametersbasedonthevisionnavigationmodelswasderived.ThereducedorderUnscentedKalmanFiltering(UKF)algorithmwasdesignedtoestimatetheinformationofrelativeattitudeangleandrelativeattitudeanglevelocity.Simulationresultsshowthattheproposedapproachprovidesaconvenientwayforobtainingtheinformationofrelativepositionandrelativeattitude,andthereducedorderUKFcanimprovetheaccuracyoftherelativeattitudedetermination.
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    CombinedControlforQuickManeuverofElasticSatellite
    RAO Wei-Dong, XU Li-Jia
    2013, 33 (6):  41-48.  doi: 10.3780/j.issn.1000-758X.2013.06.006
    Abstract ( 1385 )   PDF (471KB) ( 802 )   Save
    Acombinedcontrolmethodwhichconsistsoffeedbackcontrolandfeedforwardcontrolwaspresented.Thefeedbackloopeliminatesrigidbody′sattitudeerroraroundtargetattitude,whilefeedforwardcontrolpreventsfromelasticvibration.Forfeedbackloop,thetraditionalPDcontrolwasadopted.Forfeedforwardcontrol,thesuboptimalsinusoidalcontrolwasadopted.Suboptimalsinusoidalcontrolconsistsofseriesofsinusoidsexcitinglittlevibrationofelasticmodesfromlowordertohighorder.Numericalsimulationwascarriedouttoverifythemethod.Theresultsshowthat,byusingthecombinedcontrol,themaneuvertaskcanbefulfilledeffectivelyinthepresenceofdynamicaluncertaintiesanddisturbance.
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    NewMethodforAttitudeDeterminationofSpinSatelliteBasedon  ContinuousStarMapObservation
    NING Xiao-Lin, BAI Xin-Bei, JIANG Li-Wei
    2013, 33 (6):  49-57.  doi: 10.3780/j.issn.1000-758X.2013.06.007
    Abstract ( 1569 )   PDF (516KB) ( 839 )   Save
    Traditionalmethodsforspinsatelliteattitudedeterminationusuallyutilizeearthsensorandsunsensorasthemeasurementinstruments.Thegeneratedsystemerrorsandinstallationerrorandsoonwillleadtolargespinattitudeerrors.Consideringthisproblem,anewmethodusingcontinuousstarmapacquiredbyastarsensortoestimatethespinattitudeparametersofthesatellitewasproposed.Inthismethod,thespinaxisandtheangularvelocityofthesatellitewereusedasstatevariables,andthepixelcoordinatesofstarsobtainedthroughstarmapmatchingbetweenadjacenttimewereusedasmeasurements.ThespinattitudeparametersofthesatellitewereestimatedbyunscentedKalmanfilter.Simulationresultsshowthatwiththestarsensoraccuracyof3″,theestimationaccuracyofthespinaxisislessthan0.3448″andtheestimationaccuracyofspinangularvelocityisof10-4(°)/smagnitude.
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    ARateControlSchemeforCCSDS-IDCBasedonPriorityandR-DModel
    LI Ze-Hui, XIE Xiao-Fang, LIU Yong
    2013, 33 (6):  58-66.  doi: 10.3780/j.issn.1000-758X.2013.06.008
    Abstract ( 1400 )   PDF (895KB) ( 743 )   Save
    Targetareasaremuchmoreconcernedthanotherpartsoftheimagesinmanyremote-sensingapplications.Itisanidealwaytoperformdifferentcompressionratio  todecreasedatavolumeinanimage.AmodifiedbitrateallocationschemewasproposedtoextendthecapacityoftheConsultativeCommitteeforSpaceDataCompressionStandard(CCSDS-IDC)  forthemilitarypurpose.Anewsegmentregroupingandrankingschemewasusedtoallocatethebytesaccordingtoprioritiesofthesegments,theratioofhigh-prioritysegmentsandtheratedistortionmodel.Theresultsshowthatboththelocalpeaksignaltonoiseratioandthevisualeffectofthereconstructedimageareimprovedbythescheme.
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    LEOSpacecraftMagnetismPropulsionandItsCapabilityEstimation
    XIAO Xin-Xin, LI Wen-Hao, ZHANG Heng, LIU Kai-Lei
    2013, 33 (6):  67-73.  doi: 10.3780/j.issn.1000-758X.2013.06.009
    Abstract ( 1255 )   PDF (427KB) ( 1262 )   Save
    Accordingtothecharacteristicsofthemagneticfielddistributionintheearthspace,thepropulsiontechnologywithoutpropellantconsumptionwasproposedtomaintainorchangetheLEOspacecraftaltitude.Themagneticthrustdynamicswasmodeledbasedonthefundamentalmagnetics,themagnetismpropulsionprinciplewithcontinuousthrustbutnopropellantconsumptionwasclarified,andthetrackingcontrolstrategyofgeomagneticlineofforcefordecouplingthemagneticmomentwasproposed.Theflightenvelopeofmagnetismpropulsionandtypicalcalculationsfortheorbitaltitudemaintenanceorchangeswascarriedout.Theresultsshowthatthemagneticmomentofthespacecraftcanbeusedtomaintainorchangethespacecraftaltitudefrom600kmto1000kminlowearthorbit(LEO)whenitisupto106Am2.Furthermore,thetechnicalfeasibilityofobtaininghighmagneticmomentisbrieflyanalyzed.
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    ModelAnalysisofPLLSwingScanningControlSystem
    TANG En-Sheng, YUAN Jin-Peng
    2013, 33 (6):  74-80.  doi: 10.3780/j.issn.1000-758X.2013.06.010
    Abstract ( 1376 )   PDF (412KB) ( 1117 )   Save
    Thephaselockedloop(PLL)swingscanningcontrolmethodisextensivelyappliedforaerospaceopticsscanningremotesensor,whichcanberealizedwithsimpleandreliablecontrolcircuit.However,thecontrolsystemmodeliscomplicatedforphasedetectornon-linearityandswitcheffectofspringslices,anditisdifficulttoanalysisanddesignforthiscontrolsystem.Thevariousnonlinearcharactersin PLL swingscanningcontrolsystemwereanalyzed,andalinearizedmodelwasobtainedbyapplyingsmall-signalanalyticmethod,whichwasconvenientforanalysisanddesign.Basedontheproposedmodel,thecontrollerdesignrulewasalsodiscussed,andanexperimentwascarriedouttoconfirmtheanalysisconclusion.
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