基于信息理论的INS／Vision相对导航系统可观测度分析

基于导弹编队协同作战的应用背景，提出了一种基于INS／Vision的相对导航方法。推导了领弹与从弹间的相对惯导方程，给出了使用视觉导航设备测量领弹与从弹间相对视线矢量的原理。用扩展卡尔曼滤波融合相对惯导信息和相对视线矢量信息，估计相对位置、相对速度和相对姿态。用信息理论分析相对导航系统可观测度，给出随机变量的熵和共有信息的定义，将共有信息作为系统可观测度的衡量标准，分析了INS／Vision相对导航系统状态的可观测度，由此确定位置估计精度最高时领弹与从弹间的相对位置关系。仿真研究验证了相对导航方法的有效性和可观测度分析结果的正确性。

Observability Analysis of Relative Navigation System Based on INS/Vision via Information-Theoretic Approach

An approach of relative navigation based on INS/Vision was presented based on the application of cooperative formation missiles in this paper. The relative inertial equation between leader missile and follower missile was derived and the measurement principal of line of sight was provided. The extended Kalman filtering was applied to fuse relative inertial information with line of sight to estimate the relative position, velocity and attitude. The information-theoretic approach was utilized to analyze observability of relative navigation system. The definition of entropy and mutual information for random variables were provided. Furthermore, the mutual information was used as the criterion of observability. Therefore, the relative position between leader missile and follower missile could be determined when the highest accuracy was obtained. The simulation results proved the effectiveness of relative navigation appraoch and the rightness of observability analysis.