Robust and non-fragile H∞ controller design with fuzzy compensator for hovering helicopter

Hovering helicopters have severe nonlinearity and uncertainties. In this paper, we describe the synthesis of robust and non-fragile H-infinity controllers for linear time varying systems with affine parameter uncertainties, as well as static state feedback controller with polytopic uncertainty. For practical control design, we use fuzzy logic controllers of Mamdani type to compensate the nonlinearity. The sufficient condition of controller existence, the design method of robust and non-fragile H-infinity static state feedback controller with fuzzy compensator, and the region of controllers which satisfies non-fragility are presented. Also, the obtained condition can be rewritten as Parameterized Linear Matrix Inequalities (PLMIs), that is, LMIs whose coefficients are functions of a parameter confined to a compact set.