Comparative study of various control methods for attitude control of a LEOsatellite

A nonlinear attitude model of a satellite with thrusters, gravity torquers and a reaction wheel cluster is developed. Then the linearized version of t his satellite attitude model is derived for the attitude hold mode. For com parison purposes, various control methods are considered for attitude contr ol of a satellite. We consider a proportional derivative controller which i s actually used in the remote sensing satellite, KOMPSAT. Then a comparison is made with an H-2 controller, an H-infinity controller, and a mixed H-2/ H(infinity)controller. The analysis and numerical studies show that the pro portional derivative controller's performance is limited in the sense that the pitch angle cannot approach zero. The simulations also show that among three control methods (H-2 control, H-infinity control, and mixed H-2/H-inf inity control) H-2 control has the fastest response time, H-infinity contro l has the slowest and mixed H-2/H-infinity control has an intermediate valu e. On the other hand, H-infinity control used least amount of control effor t while H-2 control required the most. (C) Elsevier, Paris.