Robust stability for two kinds of uncertain fractional-order systems with structured and unstructured uncertainties

Robust stability for two types of uncertain fractional-order systems of order α ∊ (0, 1) is dealt with in this paper. For the polytope-type uncertainty case, a less conservative sufficient condition of robust stability is given; for the norm-bounded uncertainty case, a sufficient and necessary condition of robust stability is presented. Both of these conditions can be checked by solving linear matrix inequalities.