Optimal Autonomous Orbit Control of Remote Sensing Spacecraft

Kurzfassung

This paper analyses the problem of the autonomous control of a satellite in Low Earth Orbit (LEO) using an optimum controller. The type of controller considered is a standard Linear Quadratic Regulator (LQR). As the problem can also be treated as a two-satellites-formation control in which there is no cancellation of the common perturbative forces, its formulation is similar to that used in formation flying control problems. The driving orbit control requirement is to keep the satellite orbit within a maximum absolute distance of 250 m (r.m.s.) from a sun-synchronous, phased and frozen reference orbit. The control action is realized by means of in-plane and out of-plane thrusts whose cost is minimized by the optimal solution of the control problem. The PRISMA dual satellite mission flight software development and test environment is used as a first test-bed to validate the control algorithms. The PRISMA flight software and test environment allows a very realistic validation of the proposed control techniques. The TerraSAR-X mission scenario is use as a second test-bed for the validation of the control algorithm as it is a very representative example of LEO satellite for Earth observation with high demanding orbit control accuracy requirements.