Decentralised adaptive control of a class of interconnected non-linear systems with unknown time delays and dead-zone inputs

Abstract

This study presents a decentralised adaptive tracking control approach for uncertain large-scale non-linear systems with time-delayed interconnections and unknown non-symmetric dead-zone inputs. The interaction terms with unknown time-varying delays unmatched in control inputs are related to all state variables and are compensated by choosing the appropriate Lyapunov-Krasovskii functionals and using the adaptive technique. The local memoryless controller for each subsystem is simply designed using the dynamic surface design technique, without constructing the dead-zone inverse and requiring the information of all dead-zone parameters and bounds of unknown time delays. It is shown that all signals of the controlled closed-loop systems are semi-globally uniformly bounded and each tracking error converges to an adjustable neighbourhood of the origin.