Decentralized Adaptive Robust Control of Uncertain Large Scale Systems Including Time-Varying State Delays in the Nonlinear Interconnections

The problem of decentralized adaptive robust stabilization is considered for a class of uncertain large scale time–delay systems with nonlinear interconnection terms. It is assumed that the upper bounds of the uncertainties and the interconnection terms are unknown, and that the time–varying delays are any nonnegative continuous and bounded functions, and do not require that their derivatives have to be less than one. In particular, it is only required that the nonlinear interconnection terms, which can also include time–varying delays, are bounded in any nonnegative nonlinear functions which are not required to be known for the system designer. For such a class of uncertain large scale time–delay nonlinear systems, a new method is presented whereby a class of decentralized local adaptive robust state feedback controllers with a rather simpler structure is proposed. It is also shown that the solutions of uncertain large scale time–delay interconnected systems can be guaranteed to be uniformly exponentially convergent towards a ball which can be as small as desired. Copyright c ©2011 IFAC