行星探测光学导航方法及误差分析

Optical Navigation and Error Analysis for in Planetary Exploration

针对月球及行星探测器下降着陆导航问题,提出一种基于空间位置分布模型的高精度光学导航方法。该方法在环形山检测基础上,根据环形山物像对应关系,构建成像余弦等价数学模型;对探测器空间位置的几何分布予以描述,形成阿贝尔李群空间圆环面,实现参数化光学导航绝对定位;最后以拟合椭圆为典型分析对象,推证了环形山检测误差对光学导航系统定位、定姿精度影响的数学表达式;分析了不同环形山分布构型、不同探测精度对提出方法性能的影响。蒙特卡洛仿真实验结果表明,所提出方法与现有行星探测视觉辅助导航等方法相比,位置精度提高约10%(RMS)。

An optical navigation method based on spatial position distribution model is proposed, aiming at the problem of high-precision optical navigation during descent and landing in lunar and planetary exploration. Based on the crater detection results, the proposed method constructs the imaging cosine equivalent mathematical relation according to the corresponding relation between the object and image of the craters to describe the geometric distribution of the probe’s spatial location, forming an Abelian Lie group space torus and parameterizing the absolute positioning of optical navigation. Finally, taking the fitting ellipse as a typical analysis object, the effects of measurement error in crater detection on the positioning and attitude determination of optical navigation system are explored. The effects of different crater distribution configurations and different detection errors on the performance of the proposed optical navigation algorithm are analyzed. The Monte Carlo simulation results show that the proposed method improves the position accuracy by about 10%(RMS) compared with existing methods such as visual aided navigation for planetary exploration.