SATELLITE FORMATION-KEEPING ABOUT LIBRATION POINTS IN THE PRESENCE OF SYSTEM UNCERTAINTIES

This paper studies a control law to stabilize the orbital motion in the vicinity of an unstable equilibrium points and periodic orbits in the circular-restricted three body problem. Utilizing the eigenstructure of the system, the fuel efficient formation flying controller via linear quadratic regulator (LQR) is developed. Then the chattering attenuation sliding mode controller (CASMC) is designed and analyzed for the in-plane motion of the circular circular-restricted three-body problem. Simulation studies are conducted for the Sun-Earth L-2 point and a halo orbit around it. The total velocity change required to reach the halo orbit as well as to maintain the halo orbit is calculated. Simulation results show that the chattering attenuation sliding mode controller has good performance and robustness in the presence of unmodeled nonlinearity along the halo orbit with relatively small fuel consumption.