Decentralized local adaptive robust state observers of large scale interconnected systems with uncertainties

The problem of decentralized adaptive robust state observer design is considered for a class of uncertain large scale dynamical systems with nonlinear interconnection terms. In the paper, it is assumed that the upper bounds of the uncertainties and nonlinear interconnections are unknown. For such a class of uncertain large scale interconnected dynamical systems, a new method is presented whereby a class of completely decentralized local adaptive robust state observers with a rather simple structure is proposed. It is also shown that for each subsystem, by employing the proposed decentralized adaptive robust state observer, the observation error between the local observer state estimate and the true state of the corresponding subsystem can be guaranteed to be uniformly exponentially convergent towards a ball which can be as small as desired, in the presence of uncertainties. Finally, some simulations of a numerical example are provided to demonstrate the validity of the theoretical results.