Decentralized output feedback control for large-scale systems with time delays

The problem of decentralized output feedback control for large-scale systems with time delays is investigated. Firstly, a class of interconnected time-delay systems are considered in the form of the triangular structure. The corresponding observer is designed and the gains can be obtained via linear matrix inequality (LNU) approach. Then, the observer based decentralized feedback controllers are presented, which can render the closed-loop systems asymptotically stable. Furthermore, the design technique is extended to cope with the stabilization problem for a large class of interconnected systems with uncertain dynamics. The state and the delayed state of unmodeled systems are included in each subsystem. Employing the developed design method, a decentralized output feedback controller is proposed. With the help of changing supply function idea, it is shown that the resulting closed-loop system is asymptotically stable. The controller and observer designed are both independent of the time delays, which will render our main results more suitable for practical applications.