Pose Measurement of a GEO Satellite Based on Natural Features

In order to perform the on-orbit servicing mission, the robotic system is firstly required to approach and dock with the target autonomously, for which the measurement of relative pose is the key. It is a challenging task since the existing GEO satellites are generally non-cooperative, i.e. no artificial mark is mounted to aid the measurement. In this paper, a method based on natural features is proposed to estimate the pose of a GEO satellite in the phase of R-bar final approach. The adapter ring and the bottom edges of the satellite are chosen as the recognized object. By the circular feature, the relative position can be resolved while two solutions of the orientation are obtained. The vanishing points formed by the bottom edges are applied to solve the orientation-duality problem so that the on board camera requires no specific motions. The corresponding algorithm for image processing and pose estimation is presented. Computer simulations verify the proposed method.