Theattitudecontrolsystemdesignanditscontroleffectareaffectedconsiderablybythemass-propertyparametersofthespacecraft.Inthemissionofon-orbitservicing,asfuelisexpended,orthepayloadsareaddedorremoved,thecenterofmasswillbechangedincertainaxe;consequently,somethrusters’directionsaredeviatedfromthecenterofmass(CM)incertainplane.TheCMofassembledspacecraftestimationandthrusterdirectioncontrolarestudied.Firstly,theattitudedynamicsoftheassembledspacecraftisestablishedbasedontheNewton-Eulermethod.Secondly,theestimationcanbeidentifiedbytheleastrecursivesquaresalgorithm.Then,aschemetocontrolthethrusters’directionsisproposed.Byusingthegimbalinstalledattheendoftheboom,theangleofthethrusteriscontrolledbydrivingthegimbal;therefore,thrusterscanbedirectedtotheCMagain.Finally,numericalsimulationsareusedtoverifythisscheme.Resultsofthenumericalsimulationsclearlyshowthatthiscontrolschemeisrationalandfeasible.
