Autonomous relative attitude estimation of asteroid exploration

In this paper, autonomous relative attitude estimation between satellite and asteroid is implemented to realize the missions of asteroid flyby and companion flight. In order to achieve this aim, the relative motion equation between the satellite and the target celestial body is derived in the line-of-sight coordinate system. The features of the algorithm include-the dynamics of the relative motion is investgated in a different reference coordinate system instead of commenly used local orbit coordinate system; the discrete extended kalman filter is proposed combined with a continuous extended kalman filter and attitude nonlinear model to estimate attitude orientation. The simulation show that the EKF filter design based on line-of-sight coordinate system can obtain good filtering performance by adjusting the parameters, and achieve autonomous relative orientation attitude estimation.