一种深空自主导航系统可观测性分析方法

针对非线性系统的可观测性,本文结合微分几何相关理论通过李导数求解系统的可观测矩阵,利用条件数给出了一种衡量系统可观测度的分析方法;将其应用于基于太阳视线矢量的深空自主导航系统的可观测性分析,研究了不同轨道参数对系统可观测性能的影响;为进一步验证导航系统可观测度与状态估计精度之间的关系,结合非线性扩展卡尔曼滤波建立导航算法,对不同可观测度条件下的自主导航系统分别进行仿真分析.从仿真结果可以看出,本文提出的可观测性分析方法是可行的。

An observability analysis method of deep space autonomous navigation system

For the observability of nonlinear system, the observability matrix was derived using the Lie differentiation combining with the correlation theory of differential geometry, and an analytic method to measure the observability degree of nonlinear system was given. Then the method was applied in the observability analysis of deep space autonomous navigation system based on the Sun line-of-sight vector. The variations of observability degree for different orbital elements were investigated. Furthermore, in order to verify the relation between the observability degree and the estimation accuracy of the navigation system, the navigation process under different observability degrees was performed based on the extended Kalman filter. The method of the observability analysis proposed in this paper was demonstrated to be feasible from simulation results.