Inertia parameter and attitude estimation of space noncooperative tumbling target based on a two-step method

Abstract

This paper presents a new two-step method to estimate the ratios of the moment of inertia, the direction of the angular momentum in inertial frame, the attitude and angular velocity of the space noncooperative tumbling target, based on the measured relative attitude from the servicing spacecraft. At the beginning, the target's body frame should be determined based on its geometrical shapes. In the first step, by utilizing the conservation of angular momentum and kinematic equations, the ratios of inertia matrix in the body frame is first obtained using least square method and singular value decomposition, then the principal axis of inertia and the ratios between each principal moment is determined though coordinate transformation. In the second step, an Extended Kalman Filter (EKF) is proposed to estimate the direction of the angular momentum, attitude and angular velocity in the body-fixed coordinate frame which is rebuilded based on the direction of the principal axes from the first step. Numerical simulation results are finally presented to demonstrate the effectiveness of the proposed two-step estimation method.