Positive real control problem for uncertain linear time-invariant systems

This paper focuses on positive real control of linear time-invariant systems which are subjected to norm-bounded uncertainties in the state equation. We address the problem of designing a linear dynamic output feedback controller that robustly stabilizes the uncertain system and achieves the extended strict positive realness property for a given closed-loop transfer function. It is shown that a solution to the above problem can be obtained by solving a scaled strict positive real control problem for which no parameter uncertainty occurs.