In this paper we consider the H<FONT FACE=Symbol>¥</FONT> control problem for systems with algebraic constraints in the states. The discrete and continuous time cases are considered. Necessary and sufficient LMI conditions are presented for state feedback control problems, and only sufficient LMI conditions for output feedback. The results are also extended to cope with systems having algebraic constraints and politopic uncertainties.
Descriptor System; LMI; H<FONT FACE=Symbol>¥</FONT> control
