Autonomous acquisition and maintenance of a satellite constellation using LQG/LTR optimal controller with GPS measurements

The subject of this paper is the autonomous orbit acquisition and maintenance for a satellite constellation. The digital LQG/LTR Optimal Controller using GPS measurements are used for implementing the autonomous onboard real-time closed-loop feedback orbit control for the acquisition and maintenance of a satellite constellation. The input to this autonomous orbit control is the GPS information data (3 or 4 code pseudo ranges) and the output of this system is the optimal LQG/LTR control law for closed-loop feedback. This paper shows that this control system is completely controllable and completely observable and the closed-loop feedback system is a asymptotically stable, The Loop Transfer Recovery technique for the discrete-time system is used to enhance the performance and stability robustness of this digital control system. The measurement and control simulations of the discrete-time system show that the control system design is feasible and the system performance satisfies the design requirements. Various simulation results provided in this paper indicate that this digital GPS optimal output feedback control system can be applied to autonomous orbit acquisition and maintenance control for satellite constellations.