Robust adaptive fuzzy semi-decentralized control for a class of large-scale nonlinear systems using input-output linearization concept

Stable direct and indirect adaptive fuzzy controllers based on input-output linearization concept are presented for a class of interconnected nonlinear systems with unknown nonlinear subsystems and interconnections. The interconnected nonlinear systems are represented not only in the canonical forms as in Yousef et al. (Int. J. Robust Nonlinear Control 2006; 16: 687-708) but also in the general forms. Hybrid adaptive fuzzy robust tracking control schemes that are based on a combination of an H∞ tracking theory and fuzzy control design are eveloped. In the proposed control schemes, all the states and signals are bounded and an H∞ tracking control performance is guaranteed without imposing any constraints or assumptions about the interconnections. Extensive simulation on the tracking of a two-link rigid robot manipulator and a numerical example verify the effectiveness of the proposed algorithms.