The authors present a study of the H-infinity control problem and related topics for descriptor systems, described by a set of nonlinear differential-algebraic equations. They derive necessary and sufficient conditions for the existence of a controller solving the standard nonlinear H-infinity control problem considering both state and output feedback. One such condition for the output feedback control problem to be solvable is obtained in terms of Hamilton-Jacobi inequalities and a weak coupling condition; a parameterization of output feedback controllers solving the problem is also provided. All of these results are then specialized to the linear case. The derivation of state-space formulae for all controllers solving the standard H-infinity control problem for descriptor systems is proposed. Among other important topics covered are balanced realization, reduced-order controller design and mixed H₂/H-infinity control. "H-infinity Control for Nonlinear Descriptor Systems" provides a comprehensive introduction and easy access to advanced topics.

From the reviews:

"The monograph presents a study of the H infinity control problem and related topics for descriptor systems, described by a set of nonlinear differential-algebraic equations. The target group of the monograph is aimed to be academic researchers in control theory, nonlinear systems and control engineering. Necessary and sufficient conditions are derived for the existence of a controller solving the standard nonlinear H infinity control problem considering both state feedback and output feedback." (Ilkka Virtanen, Zentralblatt MATH, Vol. 1113 (15), 2007)