Observer-PI scheme for the stabilization and control of high order delayed systems with one or two unstable poles

This paper considers the problem of stabilization and control of linear time invariant high order systems with one or two unstable real poles, n real stable poles plus time-delay. In order to ensure a stable behavior of the closed loop system, necessary and sufficient conditions for the existence of an observer based controller together with a PI compensator are shown explicitly. Numerical simulation on academic examples are provided to illustrate the effectiveness of the proposed control strategy