A multi-cue-based relative navigation algorithm for spacecraft via dual number representation

A vision-based relative navigation algorithm for spacecraft is addressed in this paper. Based on the dual number, a relative coupled dynamic equation is derived which can describe both the rotational motion and the translational motion of the chaser spacecraft relative to the target spacecraft, and the effect of rotation-translation coupling due to the point deviating from the center of the mass of the spacecraft. In the dual algebra, the feature lines and points are described uniformly. A multi-cue-based measurement model is proposed using the 2-D images of the feature lines and points fixed on the target spacecraft, and the iterated extended Kalman filter (IEKF) is applied to estimate the relative state between the points off the center of the mass of the two spacecraft. Numerical simulations are performed to demonstrate that the proposed approach can provide an accurate estimation of the relative position and attitude of points deviating from the center of the mass of the spacecraft.