This paper introduces a new method for the attitude control of a flexible satellite. A Koreasat is selected as a flexible satellite. A structural model is obtained by use of MSC/NASTRAN and quoted from a reference. "Frequency-weighted LQG with model error sensitivity suppression" is proposed as a new control method for flexible structures. This method has characteristics which frequency-weighted LQG and model error sensitivity suppression have. The performance of frequency-weighted LQG with model error sensitivity suppression is compared with that of LQG, LQG/LTR, model error sensitivity suppression, and frequency-weighted LQG.
The order of a structural model is generally too high to design a controller by use of modern control design techniques. Thus model reduction methods are studied in this paper such as balanced realization method, Schur method, optimal Hankel norm method, singular perturbation method, and modal truncation method.
