A Monocular Structured Light Vision Method for Pose Determination of Large Non-cooperative Satellites

A space robotic system is expected to perform on-orbit servicing missions to rescue malfunctioned satellites in geostationary orbit (GEO). In final berthing and capture, it is difficult for a space robot to determine the relative pose (attitude and position) of a non-cooperative malfunctioned satellite that is usually huge and without artificial recognition devices. In this paper, a space robot with a monocular structured light vision subsystem is introduced to solve the problem. Firstly, the monocular structured light vision subsystem composed of a single camera and a point light source is designed. Secondly, a partial rectangular shaped framework, which is very common on a non-cooperative malfunctioned satellite, is chosen as the recognition object for non-cooperative pose measurement. Using projection constraints on rectangle and circular points, a rectangle feature reconstruction algorithm is proposed. Thirdly, according to the reconstructed rectangle feature, a least square method of pose determination is presented. Lastly, using a semi-physical vision simulation system, several experiments of typical cases are simulated to verify the pose determination method of large non-cooperative target. The results show the validity and flexibility of the proposed method.