【摘要】 在月球极区着陆探测任务中，基于陨坑视觉导航估计着陆器位姿可以实现高精度着陆定位。为解决陨坑视觉导航中位姿估计误差传递机理不明确、工程实用化参数缺失等关键问题，开展了陨坑视觉导航的位姿估计误差建模研究。通过提出一种基于加权最小二乘法的位姿误差模型，以估计多种因素影响下的位姿误差。首先，结合陨坑视觉导航位姿估计原理，完成位姿误差溯源分析与基础建模。其次，以重投影误差最小化为目标，构建位姿误差模型。最后，采用加权最小二乘法，完成位姿误差的定量估计。基于月球极区数字高程模型（Digital Elevation Model, DEM）和数字正射影像（Digital Orthophoto Map, DOM）数据，模拟月球着陆器的陨坑视觉导航，开展基于蒙特卡洛仿真的位姿误差估计实验，研究不同误差源和特征参数对位姿误差的影响。实验结果表明，当像素检测误差为5 pixel、陨坑数量为15时，平移误差估计值小于95 m。本文误差模型可实现多因素影响下位姿误差的定量估计，提出的工程参数方案满足月球极区着陆百米级导航精度要求，为陨坑导航方案设计提供了理论基础。更多还原

【Abstract】 High-precision positioning is required for lunar polar landing, and crater-based visual navigation can be used to estimate the lander pose. However, this approach is limited by an insufficiently characterized mechanism for pose estimation error propagation and by the lack of practical engineering parameters. To address these issues, pose error modeling for crater visual navigation is investigated. A pose error model based on weighted least squares is proposed to quantify pose errors under the combined effects of multiple factors. First, traceability analysis and baseline modeling of pose errors are performed according to the pose estimation principle of crater visual navigation. Second, a pose error model is formulated by minimizing the reprojection error. Finally, weighted least squares is applied to obtain quantitative pose error estimates. Using DEM and DOM data from the lunar polar region, crater visual navigation for a lunar lander is simulated, and Monte Carlo-based experiments are conducted to evaluate the effects of different error sources and feature parameters on pose accuracy. When the pixel detection error is 5 pixels and 15 craters are used, the estimated translation error is below 95 m. The developed model enables quantitative pose error estimation under multiple contributing factors, and the proposed engineering parameter scheme satisfies the 100 m-level navigation accuracy requirement for lunar polar landing. This work provides a theoretical basis for the design of crater-based navigation schemes.更多还原