Robust Attitude Control for a Rigid Body Spacecraft

Just as with other electronics and terrestrial technologies, satellites have become increasingly compact and more capable. A class of satellites called cubesats, or more specifically nanosatellites, have arisen as an emerging prominent standard for small satellites, in particular in low-Earth orbit (LEO). With projections of increased data downlink requirements as well as higher frequency up to even infrared and optical bands, the need for very precise and robust pointing control becomes paramount [1]. In the past few years, cubesats have become increasingly more capable and can accumulate vast amounts of data and thus must leverage higher frequencies to downlink the data at a sufficient rate [2]. In order to achieve pointing at higher frequencies, accurate control that can account for even minor disturbances must be employed. In this paper, we compare a robust feedback linearization controller (RFLC) method to provide stabilization as compared to a PID and a non robust FLC. Additionally, we assess performance of the RFLC using a second-order linear actuator model and saturation block to better emulate a realistic system.