Fusion of Absolute Vision-based Localization and Visual Odometry for Spacecraft Pinpoint Landing

In this paper, we present the vision-based absolute navigation (VIBAN) system that enables the global localization ability (also called ”pinpoint landing”) of the lander. The system integrates the absolute visual localisation (AVL) approach Landstel with visual odometry (VO), a relative visual motion estimation approach. The combination of the two vision-based sensors has several advantages. Firstly, a higher accuracy and a better robustness in localization ability is obtained, as in a GPS-INS fusion system. Secondly, the AVL system can exploit the points tracked by visual odometry in order to robustify the system itself. Finally, these tracked points are also used according to a fault detection approach to verify and check the correctness of the AVL algorithm. Extensive simulations illustrate the proposed approach.