双目视觉导航信息的可观测性分析

本文针对飞行器相对导航中双目视觉测量系统的可观测性问题进行了研究。推导了系统估计的Fisher信息矩阵，提出利用Fisher信息矩阵的秩分析来判断双目视觉导航信息观测性的方法，研究了特征点个数及分布与Fisher信息矩阵秩及相应系统可观测性的关系，得出至少2个特征点能满足双目视觉测量系统完全可观测的结论。结合测量方程的不同，分析比较了在相同特征点个数情况下单目视觉与双目视觉测量系统可观测性的优劣，最后，通过单幅图片位置和姿态确定数值仿真，验证了基于Fisher信息矩阵的双目视觉系统可观测性分析结论的正确性。

Observability Analysis of Binocular Vision Navigation Information

The observability problem of binocular vision measurement system in spacecraft relative navigation is studied in this paper. The Fisher information matrix of system estimation is derived and the method for observability analysis based on the rank analysis of Fisher information matrix is proposed. The interrelationships among   the number and distribution of characteristic points, the rank of Fisher information matrix, and the system observability are studied. The conclusion is that at least 2 characteristic points are needed to insure the fully observation. At last, the observabilities of both monocular vision and binocular vision measurement system are compared according to differences of measurement equations under the same number of characteristic points. Simulation results of position and attitude determination for single picture confirm the conclusion obtained from the rank analysis of the Fisher information matrix.