The research of on-orbit parameters estimation for on-orbit-servicing spacecraft relative to out-of-control spacecraft

An on-orbit parameters estimation algorithm is presented to acquire the real time parameters of out-of-control target spacecraft for the on-orbit-servicing spacecraft by using a monocular image sequence. Considering the straight outline feature of the uncooperative target as observed object and using the dual quaternion to describe the relative transition and attitude motion, the paper establishes the camera observed model and target motion model. With these models and take the parameters of target, including transition, attitude, inertia ratio, as the state variables, the system state equation and observed equation which are suitable for the IEKF are deduced. The state information updates iteratively in one filter period is the advantage of IEKF, which can be used to reduce the error of the observed equation linearization and ensue the stability of the whole estimation algorithm. Finally, a simulation is carried out and the results indicate that the algorithm can be used on-orbit to estimate the real time parameters of out-of-control target spacecraft.