Attitude Estimation of Space Non-Cooperative Target Based on Conformal Geometric Algebra

Abstract

The identification and estimation of space non-cooperative targets are prerequisites for space rendezvous and docking, and in-orbit capture missions. In this paper, a method for six-degree-of-freedom attitude estimation of spatial noncooperative target based on conformal geometric algebra(CGA) framework was be proposed. Firstly, we use a construction method of straight lines in CGA to fit straight lines to the points on the outer contour of the single-frame point cloud of the noncooperative target. Secondly, we fit the points on the straight line to a circle by spherical inversion in CGA. Finally, the transformation relationship between the point cloud sequences is solved by constructing a minimization distance objective function to obtain real-time six-degree-of-freedom attitude information of the noncooperative target. Both numerical simulation experiments and semi-physical experiments demonstrate the effectiveness of our proposed method, with the estimation error of the attitude angle less than 1.8° and the translation error less than 0.1m.