Relative Pose Determination of Uncooperative Spacecraft Based on Circle Feature

Abstract

This paper investigates the problem of spacecraft relative navigation with respect to an unknown target during the close-proximity operations in the on-orbit service system. The serving spacecraft is equipped with a Time-of-Flight (ToF) camera for object recognition and feature detection. A fast and robust relative navigation strategy for acquisition is presented without any extra information about the target by using the natural circle features. The architecture of the proposed relative navigation strategy consists of three ingredients. First, a point cloud segmentation method based on the auxiliary gray image is developed for fast extraction of the circle feature point cloud of the target. Secondly, a new parameter fitting method of circle features is proposed including circle feature calculation by two different geometric models and results’ fusion. Finally, a specific definition of the coordinate frame system is introduced to solve the relative pose with respect to the uncooperative target. In order to validate the efficiency of the segmentation, an experimental test is conducted based on real-time image data acquired by the ToF camera. The total time consumption is saved by 94%. In addition, numerical simulations are carried out to evaluate the proposed navigation algorithm. It shows good robustness under the different levels of noises.

The general method of the tanker car mouth pose measurement

“…The algorithm deduces the pose conversion relationship between the ellipse in the image and the circle in the camera coordinate system, but the final result will produce ambiguity and does not solve the problem of ambiguity. Liu et al (2021aLiu et al ( , 2021b added the time of flight camera to the calculation of spacecraft relative navigation problems relative to unknown targets. The circle depth information of the circle is constrained, and the relative pose of the object relative to the uncooperative object is solved, which effectively solves the problem of wrong pose solution in the calculation process.…”

“…Then, the center of the circle is reconstructed using the binocular stereovision triangulation technique. Liu et al (2021aLiu et al ( , 2021b propose a spatial circle pose measurement method based on binocular inverse projection transformation. According to the configuration characteristics of the lunar sampling manipulator, the normal constraint of circular target is established.…”

Relative Pose Estimation of Non-Cooperative Space Targets Using a TOF Camera

“…In space, sunlight changes greatly and target surfaces are always covered with special material without texture; thus, visual cameras cannot work well in these conditions, but active sensors [18] are robust in these conditions. Compared with LiDAR, TOF cameras have attracted widespread attention due to the advantages of compact structure and low power consumption [19] in the field of the pose estimation of non-cooperative targets. Moreover, the area array detectors of TOF cameras provide the range image [20] and 3D point cloud of the target surface in one frame without motioninduced distortion instead of scanning.…”