Decentralized global disturbance attenuation for a class of large-scale uncertain nonlinear systems

This paper studies the problem of global robust disturbance attenuation via decentralized state feedback for a class of large-scale nonlinear systems with parameter and interconnection uncertainties. The parameter uncertainty is from a compact set and the uncertain interconnections are bounded by higher-order polynomials of state variables. The problem that we address is to design a robust decentralized controller such that the closed-loop large-scale nonlinear system is input-to-state stable and the L-2 gain from the disturbance input to the controlled output is below a prescribed value for all admissible uncertain parameters and interconnections. A Lyapunov-based recursive design approach is developed to construct the decentralized controller explicitly. As a special case, the problem of almost disturbance decoupling via decentralized state feedback is also solved.