Formulation of space debris nutation motion by quaternions and estimation of attitude motion using Kalman filter

In recent decades, the increased space debris around Earth's orbit has become a severe problem due to the increased risk of collisions with spacecraft. Therefore, the development of technology to remove this debris is one of the most urgent issues. This study takes up a real-time method of estimating the decommissioned spacecraft's periodic attitude motion using video taken from the chaser spacecraft. In terms of high estimation accuracy and low calculation load, the proposed method visually tracks the feature points of the target spacecraft, and the attitude motion of the spacecraft is estimated by Extended Kalman Filter using the quaternion as the state vairable, in which both the posture direction and angular speed are instantly specified, and the singular point is accessible. The proposed method has the assumption that the target is in the nutation motion or the geometry is known. This article reports numerical simulation examples in which the proposed method estimates the nutation motion.