H/sub /spl infin// control of differential algebraic equation systems: the linearizing change of variables approach revisited

In this paper control of high index or even nonregular linear differential-algebraic-equation systems subject to H/sub /spl infin// performance constraints is considered. In a previous paper (Rehm and Allgower, 2000) this problem was addressed by a linearizing change of variables approach under a certain assumption on the structure of the algebraic equations within the system description. This restriction is overcome in the paper at hand. By means of a modified linearizing change of variables approach to the H/sub /spl infin// control problem, the synthesis conditions (given as linear matrix inequalities (LMIs)) not only become structurally simpler, but, in contrast to Rehm and Allgower, 2000, also include the case without algebraic constraints.