Accurate and complete terrain maps enhance the awareness of autonomous robots and enable safe and optimal path planning. Rocks and topography often create occlusions and lead to missing elevation information in the Digital Elevation Map (DEM). Currently, these occluded areas are either fully avoided during motion planning or the missing values in the elevation map are filled-in using traditional interpolation, diffusion or patch-matching techniques. These methods cannot leverage the high-level terrain characteristics and the geometric constraints of line of sight we humans use intuitively to predict occluded areas. We introduce a self-supervised learning approach capable of training on real-world data without a need for ground-truth information to reconstruct the occluded areas in the DEMs. We accomplish this by adding artificial occlusion to the incomplete elevation maps constructed on a real robot by performing ray casting. We first evaluate a supervised learning approach on synthetic data for which we have the full ground-truth available and subsequently move to several real-world datasets. These real-world datasets were recorded during exploration of both structured and unstructured terrain with a legged robot, and additionally in a planetary scenario on Lunar analogue terrain. We state a significant improvement compared to the baseline methods both on synthetic terrain and for the real-world datasets. Our neural network is able to run in real-time on both CPU and GPU with suitable sampling rates for autonomous ground robots. We motivate the applicability of reconstructing occlusion in elevation maps with preliminary motion planning experiments.

翻译：准确和完整的地形图提高了自主机器人的认识,并有利于安全和最佳的路径规划。岩石和地形学常常造成封闭,导致数字升降图中缺少升降信息。目前,这些隐蔽区域要么在运动规划期间完全避免,要么在高地图中缺少值,使用传统的内插、扩散或补补补技术填入。这些方法无法利用高地特征和高地图线的几何限制,我们人类直观地对隐蔽地区进行预测。我们采用了一种自我监督的学习方法,能够对实际运动数据进行培训,而无需地心图信息来重建数字升降图中隐蔽的区域。我们这样做的方法是通过进行射线铸造,将人工封存加在在以真实机器人制成的升降图上。我们首先评估合成数据的监控学习方法,为此,我们拥有完全的地平流图,随后又转到若干真实世界的数据集。这些真实世界的数据集是在初步运动数据流数据流中记录,而不需要地平流线信息流信息信息信息信息信息信息信息,以重建德国的地平基和地下地平地平地平地平地平地平地平层图和地平地平地平地平地平地平地平地平地图进行着一个比。我们对地平流和地平地平地平的地平地平的地图进行着地平地平地平地平地平地平地平地平地平地图的地形进行着地图的比。