Observer-based positive real control of uncertain linear systems

This paper is concerned with the positive control problem for a class of li near systems with norm-bounded uncertainties. We address the problem of des igning observer-based dynamic output-feedback controllers that robustly sta bilize the uncertain system and achieve the extended strict positive realne ss for a given closed-loop transfer function. By casting the problem at han d into a class of strict positive real control problems with scaling parame ters, an uncertainty-independent solution is then established and expressed in linear matrix inequalities format. (C) 1999 Elsevier Science Ltd. All r ights reserved.