Design and implementation of robust symmetric attitude controller for ETS-VIII spacecraft

To meet increasing mission requirements, communication satellites are being equipped with large flexible antenna reflectors and solar paddles. A typical such satellite, the Engineering Test Satellite VIII (ETS-VIII) spacecraft, was launched into geostationary orbit by the Japan Aerospace Exploration Agency (JAXA) in December 2006. The main mission of ETS-VIII is to support next-generation mobile digital communications, and for this purpose it is equipped with two large deployable antenna reflectors and a pair of large solar paddles that rotate around the pitch axis. The authors are planning to perform on-orbit attitude control experiments using ETS-VIII at the end of its mission life, aiming to develop a baseline for future controller design for this class of satellite using advanced control theories. This paper proposes two degrees-of-freedom control based on robust direct velocity and displacement feedback as a candidate controller technology. The spacecraft modeling and controller synthesis methods are discussed, and a controller implementation for an on-orbit control experiment is presented with simulation results.