Nonlinear method for multiple-impulse hovering control of spacecraft

Continuous thrust hovering could be difficult to implement, which needs strict control and propulsion systems of spacecraft. For solving the problem, a method of spacecraft multiple-impulse hovering, based on the Clohessy-Wiltshire equations, is proposed in this paper. The hovering method includes the nonlinear predictive method of spacecraft states and the optimization algorithm of impulse. With this method, the active spacecraft can hover approximately at any selected position near the target spacecraft. For considering the effect of linearization and J₂ perturbation, the method improves the hovering accuracy. The numerical simulation shows that the two spacecraft can maintain a stable hovering, and the energy requirements of the active spacecraft are not much more than the one based on the continuous thrust.