Design of functional interval observers for nonlinear fractional-order interconnected systems

Abstract

ABSTRACTIn this paper, we address problem of distributed functional interval observers for a class of nonlinear fractional-order interconnected systems with bounded uncertainties. The system under consideration is formed by N () interconnected subsystems. We first design N stand-alone distributed functional interval observers for the system. The designed interval observer for each subsystem is based on the local outputs, known bounds of the local uncertainty and additional outputs from other subsystems but without the need to exchange the state estimates among the observers. Then, conditions for the existence of such distributed functional interval observers are derived and an effective algorithm for computing unknown observer matrices is provided. Finally, two numerical examples and simulation results are given to illustrate the effectiveness of the proposed design method.