关键词: 航天器变轨, 迭代制导, 最优控制, 坐标转换, 开关机点优化, 权重调整

Abstract: Sincethethrustamplitudeofthemainengineonspacecraftisunadjustable，amultipleterminalconstrainbasedoptimalguidancemethodwasproposed，consideringthedeficiencyofsmallcorrectionangleassumptionofconventionaliterativeguidanceunderfiveterminalconstrains.Anoptimalcontrolmodelwasestablishedintheorbitinjectionorbitalcoordinateframe.Transversalityequationswaredirectlysolvedbyiterationtoobtaintheguidanceanglecommand.Theswitchonandoffinstantswerethenoptimizedtoreducetheinfluenceofunsatisfiedterminalconstraints.Besides, thefiveequivalentterminalconstraintsinthegeocentricinertialcoordinateframewerederivedandappropriateweightfactorswereadjustedtoimprovetheprecisionofnumericalsolvingofguidanceequations.Simulationsonstandardconditionsdemonstratethattheproposedguidancemethodhasincreasedtheprecisionofunsatisfiedterminalconstraintsby1595355m，comparedwiththeconventionaliterativeguidance.TheMonteCarlosimulationsshowtheadaptabilityoftheproposedmethodtotheinitialbiasofthespacecraftpositionandvelocity.

Key words: spacecraftorbittransfer, iterativeguidance, optimalcontrol, coordinatetransformation, switchonandoffinstantsoptimization, weightadjustment