Design and verification of a Robust formation keeping controller

Formation keeping is a key technology of distributed satellite system. In order to deal with the satellite formation keeping problem including perturbations, normalized linear equations of satellite relative motion including J2J2 perturbation are derived. Then a sliding mode variable structure control with matching uncertainty and disturbance is introduced, the method using a reaching law to design VSC controller directly for the discrete time system. Then control law for formation keeping of satellite formation in LEO with small eccentricity reference orbit is designed, so the modeling error and disturbance is included. A simulation environment with layer control architecture and nonlinear dynamics including perturbations are developed to verify the control algorithms. Simulations for various system parameters are conducted for both circular reference orbit and eccentric reference orbit. Simulation results established the robustness and performance of the controller.