Autonomous Station Keeping Using Closed-Loop Feedback With H Infinity and GPS LQG/LTR Controller

Station keeping operations of satellites are primarily planned and executed from the ground control centers. With future trends towards operating satellites as part of a larger constellation, both in geostationary orbit (collocation) and lower Earth orbits, the availability of autonomous station keeping will become more critical. This proposal envisions the design of one such innovative autonomous stationkeeping system that will implement the concept of a closed loop Feedback Control using navigational information from both celestial measurements (CM) using Earth-Sun-Polaris angular measurements, as well as GPS measurements. A GPS LQG/LTR Controller will be designed for State Feedback, while a CM PID Controller and H-Infinity Robust Controller will be used for Output Feedback. This design is expected to provide complete autonomy, and will be applicable to both geosynchronous orbits, as well as low Earth orbits. The Phase I research results will be a feasibility study of the proposed design that could eventually be implemented into a usable on-board station keeping system. This proposal is in response to DOD SBIR, 1996, and will be a 6 month offer.