Mixed H2/H∞ state-feedback design for microsatellite attitude control

Owing to a great decrease in size and weight, the pointing accuracy of microsatellite is vulnerable to space environmental disturbances and the internal uncertainty of moment-of-inertia variation. Mixed H-2/H-infinity control, giving consideration to both stability robustness and root-mean-square (rms) performance, is particularly attractive for attitude controller design of microsatellites. By using linear matrix inequality method. the numerical solution of mixed H-2/H-infinity state-feedback controller can be efficiently solved. The performance differences between mixed H-2/H-infinity controller and its two extremes-pure H-2 controller and pure H-infinity controller-are discussed in detail, Mixed H-2/H-infinity controller shows the remarkable capability of achieving a balanced compromise between H-2 and H-infinity performances. (C) 2002 Published by Elsevier Science Ltd.