中文摘要：

由于状态方程和观测方程的非线性,给自主导航系统的能观性分析带来了挑战。首先分析了条件数在线性系统能观度定义中的合理性;然后,利用李导数求解出非线性系统的能观性矩阵,并基于条件数给出了一种非线性系统的能观性度量方法;将其应用于地月转移轨道,分别研究了地心视线矢量和月心视线矢量两种观测模型下自主导航系统的能观度;进而,利用系统的能观度动态确定信息分配因子,结合扩展卡尔曼滤波建立信息融合自主导航算法。仿真结果表明,本文提出的能观性度量方法能够反映不同观测模型下系统能观性的变化情况,基于能观度的信息融合自主导航算法的轨道参数估计结果完全满足地月转移轨道段的精度要求。

英文摘要：

The observability analysis of the autonomous navigation system is complicated due to nonlinearities of state equation and measurement equation.Firstly,the rationality of the condition number in the definition of observability degree of linear system is analyzed.Then,the observability matrix of a nonlinear system is deduced by utilizing the Lie derivative,and a measure method of observability for nonlinear system is derived based on the condition number.The method is applied to the autonomous navigation system of Earth-Moon transfer orbit.The observability under two measurement models,the line-of-sight vectors to the Earth and the Moon,are investigated in detail.Furthermore,the observability degree is used to determine the information-sharing factors dynamically,and combined with the extended Kalman filter to establish an information fusion autonomous navigation algorithm.Simulation results demonstrate the validity of the method of observability analysis.Numerical results show that the estimation accuracy of the orbit parameters meets the requirements for the Earth-Moon transfer orbit.