Radial Type Satellite Attitude Controller Design using LMI Method and Robustness Analysis

The control theory using LMI method is applied to design an attitude controller of radial type satellite that has strongly coupled channels due to the large product of inertia. It is observed that the cross-over frequency of open-loop with controller is lower than that of open-loop without controller, which is not typical phenomenon in an optimal control design result: it is interpreted that due to a large product of inertia, there is certain limit in increasing agility of satellite by just tuning weighting function. -analysis is performed to verify the stability and performance robustness with the assumption of +/-5% MOI variation. -analysis result shows that the variation of principal MOI degrades the stability and performance robustness more than the variation of POI does.