姿态测量系统MEMS陀螺仪外文文献

AerospaceScienceandTechnology26(2013)10–15ContentslistsavailableatSciVerseScienceDirectAerospaceScienceandTechnology∗SchoolofAstronautics,BeijingUniversityofAeronauticsandAstronautics,Beijing100191,PRChinaarticleinfoabstractArticlehistory:Received30January2011Receivedinrevisedform26August2011Accepted13February2012Availableonline17February2012Keywords:GPSCarrierphaseAttitudedeterminationSpinningsatellitesThispaperproposesanewsubsystemofattitudedeterminationforspin-stabilizedsatellites,whichmakesuseofinformationfromsingleantennaGPSreceiverandaMEMSgyro.Theincrementalcarrierphasestateequationandmeasuremodelforspinningsatellite’sattitudemotionarederived.ThesubsystemsensesattitudebydemodulationofperiodicoscillationsoftheGPScarrierphasecausedbysatellite’sspinningmotionwiththeaidofaMEMSgyro.Numericalexamplesforspin-stabilizedsatelliteswithandwithoutnutationmotionarecarriedouttovalidatethealgorithm.Fivekeyparameterswhichaffecttheattitudesensingaccuracyareanalyzedatlast.©2012ElsevierMassonSAS.Allrightsreserved.1.IntroductionSpinstabilizationisasimplewaytokeepaspacecrafts’atti-tude,anditisalsooneofthefewwaysthatisapplicableforlowcostsatellites.Attitudedeterminationforspin-stabilizedsatellitesisoftenbasedonacombinationofmagnet,Sun,andEarthsensors[7,3].AttitudedeterminationsubsystembasedonsingleantennaGPSreceiverandMEMSgyroisveryattractive,becausethecostforsuchasubsystemisverylowandGPSreceiverisalmostastandarddeviceinlowcostsatellites.ThestandardGPS-basedsatelliteattitudesensingmethodusesmultiplespatiallydistributedGPSantennas.Thereceiver(s)re-ceivesthesignalsfromGPSsatellitesandmeasuresthecarrierphasedifferencesbetweenantennas.Givenenoughofthesemea-surements,thefull3-axisattitudeofthevehiclecanbedeter-mined.Ingeneral,threeantennasarerequiredforfullattitudeestimation.Buttheinherentbaselinemotionofspinningsatellitepermitsfullattitudeestimationwithasinglebaseline.Axelrad[1]andTortora[6]showedthatspin-stabilizedsatellite’sattitudecanbedeterminedbyonlytwoantennas.Psiaki[4]presentedanewtypeofsensorthatconsistsofasingleGPSantennamountedoff-axisonaturntable.Byusingthissensor,three-dimensionattitudeinformationcanbesensedinreal-timebydemodulationofperiodicoscillationsoftheGPScarrierphasecausedbyaturntable’srotation.Buildingsuchanattitudesensingsystemrequiresaspecializeddemodulationphase-lockedloopandahighspeedturntable.InSoltz’s[5]paper,amulti-pass*Tel.:[phone];fax:[phone].E-mailaddress:[e-mail]isdeveloped,whichcandemodulatetheGPScarrierphaseforconstantrotationspin-stabilizedspace-craftswithoff-axismountedGPSantennaandINSdata.Theleastestimationintervalofthealgorithmislimitedto30secbecausemulti-passpolynomialfittingisused.Inthispaper,atime-basedsingledifferentialcarrierphasemea-surementequationisderivedsothattherawcarrierphasemea-surementdatafromGPSreceiversandtheoutputfromaMEMSgyrocanbeuseddirectly.AnSR-UKFfilterisdesignedtodemod-ulateGPScarrierphase.Anattitudedeterminationmethodbasedoncarrierphasedemodulationisproposed.Theperformanceoftheproposedattitudedeterminationsubsystemisanalyzed.2.MeasurementmodelFig.1showsthemodifiedschematicdepictionoftheattitudedeterminationsystemasproposedinRef.[4].Apatch-typeantennaismountedontheedgeofaspin-stabilizedsatellite.Itsphasecen-terismountedoff-axiswithitsfieldofviewalignedwiththerotationaxis,sothatittranslatesaroundacircleasthesatelliterotates.Thecircularmotionoftheantenna’sphasecentercausesareceivedGPSsignal’scarrierphasetohaveasinusoidalcompo-nentasthedistancefromtheantennatotheGPSsatellitevarieswiththerotationofthesatellite.ThiscomponentismixedwiththeoriginalGPSsignal.Theamplitudeandthephaseofthecom-ponent,whichcanbededucedwiththeinformationfromaMEMSgyroandGPSpositioning,arefunctionsoftheLOS(lineofsight)vectorwhichisfromtheGPSreceiver’santennatoaGPSsatellite’santenna.ThedescriptionoftheLOSvectorisbasedonamovingcoordinate-system,wherexbybzbisamovingcoordinate-system1270-9638/$–seefrontmatter©2012ElsevierMassonSAS.Allrightsreserved.doi:10.1016/j.ast.2012.02.009C.Pei/AerospaceScienceandTechnology26(2013)10–1511Fig.1.MeasurementgeometryforattitudesensingbasedonaGPSantennamountedonaspin-stabilizedsatellite.whichisneitherinertialnorbodyfixed,zbaxisisalignedwiththespin-stabilizedsatellite’sbody-fixedaxis,theMEMSgyroisas-sembledonzb,xbaxisisalignedwiththeprojectionofthelineoftheLOSvectoronthexb–ybplane,andybisdeterminedbytheright-handrule.Thexbybzbcoordinate-systemisdefinedsothatnoturntableorrotaryencoderisrequired,andaMEMSgyro’srateoutputcanbeusedtoresolvetherotationalphaseswithrespecttotheGPSre-ceiver’sLOSvectorsinshortintervals.Highspeedrotationisnotrequiredeither.ThehighestspeedofrotationislimitedbythebandwidthoftheGPSreceiver’sPLLandtheMEMSgyro’sdynamicrange.Thepatchantenna’slocationinthexbybzbcoordinate-systemisdefinedbytherotatingangleψaandtheradialoffsetra.Ifthereisnonutation,thespin-stabilizedsatellitewillrotateataspeedωa