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    25 August 2014, Volume 34 Issue 4 Previous Issue    Next Issue
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    LowthrustMissionWindowSearchBasedonMultiimpulseEnergyEstimation
    JIANG Xiao-Yong, ZHANG Hong-Bo, TANG Guo-Jian
    2014, 34 (4):  1-7.  doi: 10.3780/j.issn.1000.758X.2014.04.001
    Abstract ( 1216 )   PDF (812KB) ( 1153 )   Save
    Amissionwindowsearchapproachwasproposedforthelowthrustmissionbasedonthemultiimpulseenergyestimation.Themultiimpulsetransfer,whichcanbeextendedrapidlyfromtheLambert′sbiimpulsesolutionwithinseveraliterations,wasemployedtoeffectivelysubstituteforalowthrusttrajectorydesign.Throughgridsearchofmultiimpulsetransfers,thefeasibleregionsofthemissionwindowwereobtained.Numericalresultsshowthat:1)theapproachissuitableforbothrendezvousandflybymissions;2)itsconsistencywithlowthrusttransferinenergyconsumptionisbetterthanthebiimpulsestrategy;3)itscomputationaltimeis1~2ordersofmagnitudelowerthanthatofSimsandFlanagan′sapproach.ItsapplicationtoanEarthMarsrendezvousmissionverifieditsvalidity.Thefeasibleregionsweregeneratedwithin8.59s,whichcanbereadilyusedtogenerateoptimallowthrusttrajectories.
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    TrajectoryPlanningAlgorithmforManipulatorsCapturingNoncooperativeObjects
    XU Shuan-Feng, YANG Bao-Hua, ZHANG Du-Zhou, ZHU Zhi-Bin, TANG Qiang, ZHANG Hai-Bo
    2014, 34 (4):  8.  doi: 10.3780/j.issn.1000.758X.2014.04.002
    Abstract ( 1228 )   PDF (785KB) ( 920 )   Save
    Amanipulatortrajectoryplanningalgorithmbasedonafeedbackcoefficientforposition/orientationerrorwasproposed.Areactionnullspace(RNS)methodwasemployedtoachievethecoordinationmotionbetweenthebasespacecraftandthemanipulatorwhichwasutilizedtoexecuteonorbitservicing(OOS).Inordertogivedesiredmanipulatormotionatanaveragejointvelocity,afeedbackcoefficientforposition/orientationerrorwasintroduced,allowingtoassignweightingfactorstothemanipulatormotion.Inordertotestandverifythetrajectoryplanningalgorithmforspacemanipulator,thehardwareintheloop(HIL)groundexperimentsimulatorwasestablished,whereafixedbasedrobotmanipulatorwasadopted.Simulationresultsdemonstratethattheproposedtrajectoryplanningalgorithmcanguaranteethatthemanipulatorendeffectorapproachthenoncooperativeobjectatawellproportionalspeed,andgrasptheobjectwithsatisfyingprecision.Itoffersaguidelinefortrajectoryplanningofspacemanipulatorwhencapturingthenoncooperativeobjects.
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    AnalysisModelingandVerificationofSolarRadiationPressureforNavigationSatellite
    CHEN Qiu-Li, WANG Hai-Hong, CHEN Zhong-Gui
    2014, 34 (4):  16.  doi: 10.3780/j.issn.1000.758X.2014.04.003
    Abstract ( 1452 )   PDF (748KB) ( 1057 )   Save
    Ananalyticalsolarradiationpressure(SRP)modelingmethodfornavigationsatelliteswasproposedtoimprovetheprecisionofpreciseorbitdetermination.ComparedwiththeotherperturbingforcemodelswhichhavemuchlargermagnitudebecauseofSunactivityleadingtochangesoftheSunenergy,satellitesattitudecontrolerror,aswellastheagingofthesatellitesurfacematerial,andasthemajoruncertaintyerrorsourcesaffectingmediumearthorbitsatellites,SRPmodelisthemostdifficulttobeconstructedprecisely.Onthebasisofattitudecontrollawofnavigationsatellite,ananalyticalSRPmodelwasdeveloped,inwhichtheperturbingaccelerationwasexpressedinsatellite′sbodyfixedcoordinatesystem.SimulationresultsofGPSBlockIIRshowthattheSRPmodelworksquitewell.ThecomputationalcostisquiteclosetothatoftheT30andECOMSRPmodel,provingthattheprecisionofSRPmodelmeetstherequirementofprimarySRPstudy.
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    SelectiononImprovedFuzzyCMeansAlgorithmofBeidouTripleFrequencyCombinationObservations
    HE Wei, TAO Ting-Ye, WANG Zhi-Ping
    2014, 34 (4):  24.  doi: 10.3780/j.issn.1000.758X.2014.04.004
    Abstract ( 1683 )   PDF (620KB) ( 1044 )   Save
    ThecombinedobservationsanderrorsofBeidousatellitenavigationsystembasedontribanddoubledifferencewerediscussed.AnincrementaldistancecorrectionbasedfuzzyCMeansalgorithmwasproposedtoovercomethedisadvantageoftheclusteringmethod,whichpreviouslyusedtostudythecombinationobservationsofGPStribanddata.Thecorrectclassificationcanbegotbyadjustingthefactorandclustercenterofthesampledistancefromthecentereffectivelytoobtainareasonabledegreeofmembershipandavoiddeterminingthenumberofclustersofhumanirrationality.Thedistancebasedclusteringvalidityindexcorrectionwascreated,andtheoptimalnumberofclusterscanbeautomaticallyobtainedbyintroducinganincrementalwhenthedatawasincreasedbasedontheoriginaldataset.Thenewdatawereclassifiedbasedontheoriginaldatasetwithoutrecalculation.Thefeasibilityandreliabilitywereprovedbythematrixtransformationmethodandtypicalexamples.
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    NumericalAnalysisontheDeploymentandFoldingProcessofLargescaleSolarSailMembrane
    HUANG Xiao-Qi, WANG Li, LIU Yu-Fei, YANG Chen, CHEN Ying
    2014, 34 (4):  31.  doi: 10.3780/j.issn.1000.758X.2014.04.005
    Abstract ( 1400 )   PDF (767KB) ( 1093 )   Save
    Forthenumericaloptimizationanalysisonthefoldinganddeploymentprocessofthesolarsailmembrane,askewleafoutfoldingpatternwasfirstlyproposedbasedontheleafinandleafoutfoldingpatterns.Fivefoldingmodelswithdifferentfoldingparameterswerebuiltuponthethreefoldingpatterns.ThefiniteelementsoftwareANSYS/LSDYNAwasusedtosimulatethedeploymentofthesefoldingpatterns.Theresultshowsthatsolarsailmembranestressalongthedeploymentprocessisrelatedtothedeploymentspeedandfoldingwidth.Theareaclosetothevertexofsquaresolarsailmembranehasthehigheststress,andshouldbereinforced.Theskewleafoutfoldingpatternisthemostappropriatefoldingpatternforthesolarsailmembrane.
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    RealtimePredictionAlgorithmforHighaccuracyGPSSatelliteClockOffset
    LEI Yu, LI Bian, ZHAO Dan-Ning, HU Yong-Hui
    2014, 34 (4):  38.  doi: 10.3780/j.issn.1000.758X.2014.04.006
    Abstract ( 1235 )   PDF (652KB) ( 804 )   Save
    InordertogetrealtimeGPSclockproductsofhighaccuracy,anewpredictionalgorithmwasproposed,whichincorporatedapolynomialmodelwithafewcyclictermsandleastsquaressupportvectormachines(LSSVM)forclockoffset.Firstly,apolynomialmodeladdingafewcyclictermswasutilizedtofittheclockoffsetseriesaccordingtothephysicalcharacteristicsofsatelliteclockssoastoextractthetrendtermandperiodicterm.Then,thepolynomialfittingresidualsweremodeledbasedontheLSSVM.Finally,thetrendtermandperiodictermwereaddedtotheforecastedresidualresulttoproducethefinalpredictionvaluefortheclockoffset.TheIGSultrarapidobserved(IGUO)productswereemployedastheinitialvaluesofthepredictionstrategy.Thesimulationresultsdemonstratethattheproposedalgorithmcanbeusedtopredictclockoffsetwithhighaccuracyinrealtime,andoutperformstheIGSultrarapidpredicted(IGUP)solutionsatleastonadailybasis.
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    SpectralAnalysisforSubpixelMaterialsBasedonKernelPartialNonnegativeMatrixFactorization
    CUI Jian-Tao, LI Xiao-Run, ZHAO Liao-Ying
    2014, 34 (4):  46.  doi: 10.3780/j.issn.1000.758X.2014.04.007
    Abstract ( 1112 )   PDF (810KB) ( 623 )   Save
    Toimprovetheaccuracyofspectralanalysisforsubpixelmaterialsfurther,anonlinearunmixingalgorithmbasedonthekernelpartialnonnegativematrixfactorization(KPNMF)wasproposed.Firstly,anendmemberextractionalgorithmbasedonthetheoryofconvexgeometrywasusedtogenerateacandidatepixelsetofpureendmembers,andthenthepureendmemberwasdeterminedaccordingtothespatialpurityindicesofthecandidatepixels.Giveninformationofpureendmembers,thekernelmethodwasadoptedtoextendpartialnonnegativematrixfactorization(PNMF).Thecorrespondingobjectivefunctionwasconstructed,andtheiterativesolutionwasalsoderivedtoobtainthesubpixelendmembersandabundancesofalltheendmembers.Theexperimentalresultsdemonstratethattheproposedunmixingalgorithmhasgoodnonlinearunmixingability,andtheunmixingresultsarebetterthanthoseoflinearunmixingalgorithms.
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    SerialMPPTElectricalPowerSystemStabilityforSpaceApplication
    LIN Wen-Li, ZHANG Xiao-Feng, DU Qing, WANG Chao
    2014, 34 (4):  53.  doi: 10.3780/j.issn.1000.758X.2014.04.008
    Abstract ( 1631 )   PDF (578KB) ( 1033 )   Save
    Instabilityphenomenasuchasbusvoltagefluctuations occurinserialmaximumpowerpointtracking(MPPT)electricalpowersystem(EPS).Tostudythestability, systemequivalentcircuitmodelswerebuiltbasedonaserialMPPTunregulatedbusEPStopologyforspaceapplication.ThesmallsignalequivalentanalysismethodandeigenvaluesofstatespaceequationssolvingmethodwereadoptedtoperformstabilityanalysisintheMPPTcontroldomainandthevoltagecontroldomain.Keyconclusionsareobtainedundertheconditionsofconstantsolararray(SA)andarraypowerregulator(APR)characteristics.ThesystemstabilitydependsontheparametersofinductorsandcapacitorsbetweentheSAandAPR.AserialMPPTunregulatedbusEPSmodelisbuiltinMATLAB/SIMULINK,andthesimulationresultsvalidatetheaboveconclusions.
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    MethodforPredictingExtremeTemperatureConditionsofSatelliteControlAntennaswithSolarHeating
    MA Wei-Chao, ZHU Min-Bo, YE Hai-Yang, LIAN Pei-Yuan
    2014, 34 (4):  59.  doi: 10.3780/j.issn.1000.758X.2014.04.009
    Abstract ( 1363 )   PDF (702KB) ( 1074 )   Save
    Consideringtheproblemsoftheelectricalpropertiesareaffectedbythermaldeformationofsatellitecontrolantenna,apredictionmethodfortheextremetemperatureconditionsofsatellitecontrolantennawaspresented.Inthemethod,thesolarradiationwascombinedwiththeparabolicantennapanelequationtocalculatethesolardirectpointtrajectoryofsatellitecontrolantennas,anddeterminedtheantennapositionparameters.Thevariousenvironmentalfactorsofantennaweretakenintoaccountandtheextremeconditionsoftheantennawerepredicted.Comparedwiththesimulationandexperimentalresults,thereliabilityofthedirectsunlightpointtrajectorycalculationmethodandthepredictionmethodsoftheextremetemperatureconditionsareverified.
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    WeakGNSSSignalsAcquisitionAlgorithmUsingTwo-stageFFT
    SU Yue, WANG Jian-Hui
    2014, 34 (4):  66.  doi: 10.3780/j.issn.1000.758X.2014.04.010
    Abstract ( 1158 )   PDF (595KB) ( 991 )   Save
    ToimprovetheimplementationflexibilityofGNSSweaksignalacquisitioninthehighdynamicenvironments,anacquisitionalgorithmincludingtwostagefastFouriertransform(FFT)wasdeveloped.Inthefirststage,theshortcoherentintegrationtimewasemployedtodividetheDopplerfrequencyrangeintoseveralsub-rangescalledcoarseDopplerfrequencybins.Inthesecondstage,thefineDopplerfrequencysearchingwascompletedbasedontheoutputofthefirststageFFT.ThepresentedmethodcanreducethenumberofFFTpointsandtheimplementationcomplexity.Besides,thepipelineprocessingwasusedinthefirststageFFT,whichcouldincreasetheefficiencyofhardwaresource.ThesimulationresultsshowthatthepresentedmethodcanacquireweakGNSSsignalscorrectlyinhighdynamicscenarios.
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    ExperimentofIonizingRadiationInducedArrayChargeCoupledDevicesDarkSignalIncrease
    WANG Zu-Jun, LUO Tong-Ding, YANG Shao-Hua, LIU Min-Bo, SHENG Jiang-Kun
    2014, 34 (4):  72.  doi: 10.3780/j.issn.1000.758X.2014.04.011
    Abstract ( 1432 )   PDF (818KB) ( 1065 )   Save
    ToresearchtheionizingradiationeffectsonChargeCoupledDevices(CCD)inspaceorbitenvironments,theexperimentsofionizingradiationeffectsonarrayCCDswerepresented.TheoutputsignalsversusintegrationtimeweremeasuredwhennolightwasincidentonthearrayCCDs.Thedarksignalslope(KD)andthedarksignalvoltages(VD)versusthetotaldoseswerepresented.Thedegradationsofdarksignalsversusthetotaldosesunderthedifferentbiasconditionswerecompared.Themechanismsofdarksignaldegradationinducedbyionizingradiationweredemonstrated.Theannealrecoveryofdarksignalwasalsomeasured.Thedarksignalnonuniformity(DSNU)versusintegrationtimeatdifferenttotaldoseswasanalyzed.TheexperimentalresultsshowthatthearrayCCDsareverysensitivetotheionizingdamage,andthedesignofthespaceimagingsystemshouldconsidertheinfluenceinducedbyionizingdamage.Theresultsprovideagoodunderstandingofthedegradations andmechanismsofthedarksignalinthearrayCCDinducedbyionizingdamage.
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    FaultManagementDesignofNHTX-1SATServiceSystem
    CHEN Zhi-Ming, LIU Hai-Ying, YE Wei-Song
    2014, 34 (4):  79.  doi: 10.3780/j.issn.1000.758X.2014.04.012
    Abstract ( 1631 )   PDF (567KB) ( 1162 )   Save
    ThegeneralinformationandthetaskservicesystemdesignofNHTX-1SATwereintroduced.NHTX-1SATisalowpowerconsumptionandhighfunctionintegrationsatellite,andthedataservicesystemistheonlycentraldataprocessingsystemthatintegratessatelliteattitudecontrolandtaskmanagementcapabilities.Basedonthesefeatures,thehardwareandsoftwaresweredesignedforthefailurepreventionmeasuresandtroubleshootingprograms,suchasthepowersafetyinsuranceandsoftwarefaulttolerancetoimprovesystemreliabilityandsafety.
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