NONLINEAR CONTROL OF ROTATING MULTI-TETHERED FORMATIONS IN HALO ORBITS

In this paper, we consider the nonlinear orbit tracking control of rotating multi-tethered satellite formations in Halo orbits. A dynamical formulation is first applied for a rotating multi-tethered formation arranged in a hub-spoke configuration. Then, a new nonlinear optimal tracking control method is proposed for the stabilization of the parent satellite to follow the predefined trajectory. Numerical simulations illustrating the effectiveness of the nonlinear controller are presented. The results show that the actual trajectory of the parent satellite tracks the nominal Halo orbit with good accuracy under the influence of initial injection errors and the perturbations of subsatellites. In addition, the control acceleration and the total fuel cost of the control can be quite reasonable. Furthermore, a number of the relevant parameters that affect the control costs are varied in order to demonstrate the robustness of the nonlinear controller.