Relative determination for non-cooperative spacecraft based on binocular vision system

Relative position and attitude determination is the prerequisites for failure spacecraft capture and removal. In this work, the binocular vision determination strategy based on image matching is developed for non-cooperative spacecraft final approach and capture, and the ground-based vision system is also established to demonstrate the effectiveness of the relative determination method. The rectangle Vertexes of the solar panel are selected as the feature point for three-dimensional reconstruction. The feature point extraction is performed as follows: At first, with a consideration of the starry background, image filtering method is proposed to suppress starry background interference; secondly, a comprehensive feature point matching method is proposed to improve the matching accuracy; finally, with the feature point extraction method based on geometry index threshold and ROI detection, the feature point of solar panel can be identified. After that, establish a target coordinate system based on the rectangular configuration; on the basis, the relative pose and position determination algorithm in ultra-close distance is developed. In order to verify the feasibility of this method, the ground-based experimental system of binocular vision is established. In the experimental system, a 3-DOF translation platform with two CCD cameras is used to simulate the tracking spacecraft, and 3-axes rotational platform is used to simulate the malfunction satellite. Two CCD cameras simultaneously measuring the low-drift motion target; IPC obtain the relative position and attitude information through calculation. The measurement accuracy can be analyzed by comparison of reference value and measurement value. Analysis results proved the effectiveness of the feature point extraction method, and the binocular vision determination method with high real time capability and accuracy is demonstrated.