Disturbance observer based attitude control for flexible spacecraft with input magnitude and rate constraints

In this paper, we investigate the problem of attitude control design for flexible spacecraft with external disturbance, input magnitude and rate constraints. First, a disturbance observer is designed to estimate and compensate for the disturbances including the external disturbance and vibration from the flexible appendages. Then, based on the disturbance observer, a sample state feedback control scheme is proposed for flexible spacecraft subject to input magnitude and rate constrains, using the linear matrix inequality (LMI) and Lyapunov direct method. Finally, the results are illustrated using numerical simulations for control performance verification.