Design of decentrailized block backstepping controllers for perturbed large-scale systems to achieve asymptotic stability

A design methodology of decentralized adaptive block backstepping controller is proposed in this paper for a class of large-scale systems with interconnections to solve regulation problems. The perturbation estimation mechanism is employed in the proposed control scheme so that the derivatives of virtual input functions do not need to be computed directly, and the upper bounds of perturbation estimation errors are not required to be known in advance. The proposed robust controller with adaptive mechanisms embedded is designed in accordance with the last block by using Lyapunov stability theorem, so that the upper bounds of interconnections as well as perturbations are not required to be known either. Furthermore, the dynamic equations of each subsystem do not need to strictly satisfy the block strict feedback form, and the resultant controlled system can achieve asymptotic stability. A numerical example is given for demonstrating the feasibility of the proposed control scheme.