Three-axis magnetic attitude control algorithms for small satellites in the presence of noise

This paper studies the three-axis attitude stabilization problem for a nadir-pointing spacecraft using only magnetic torquers as actuators. Since magnetic control systems are relatively lightweight, require low power and are inexpensive, they are attractive for small, inexpensive satellites in low Earth orbits. In this paper we present three-axis attitude control algorithms for small satellites using only magnetic torquers in the presence of noise and investigate their performance through simulations. These algorithms combine ideas from averaging and linear quadratic regulation as well as sliding mode design. Computer simulations are included to illustrate the effectiveness of the proposed control laws.