Pose and motion estimation of unknown tumbling spacecraft using stereoscopic vision

This paper develops a method to estimate the relative pose, motion, and center of mass of an unknown tumbling target using stereoscopic vision. First, the positions and velocities of detected feature points on the spacecraft are tracked and estimated by the measurements of optical flow and photogrammetry. Random observation noises are included in the process. Second, the angular velocity and attitude of the target are estimated by the least square method and q-method, respectively. Finally, the position and velocity of the center of mass of the spacecraft are recovered based on the relative kinematics of the target by successive images over a predefined observation period. Numerical simulations are conducted to demonstrate the effectiveness and precision of the proposed method.