Decentralized disturbance attenuation for large-scale nonlinear systems with delayed state interconnections

The problem of decentralized disturbance attenuation is considered for a new class of large-scale nonlinear systems with delayed state interconnections. This class of large-scale time-delay systems broadens most existing classes of large-scale time-delay systems in that the uncertain interconnections are bounded by general nonlinear functions instead of linear or polynomial-type functions. It is shown that by decentralized memoryless state feedback control, the closed-loop system achieves internal global asymptotical stability in the sense of Lyapunov and external stability in the sense of L/sub 2/ gain. Nonlinear Lyapunov-Krasovskii functionals are constructed which renders the linear and polynomial-type growth conditions on the interconnections as special cases.