Control of large scale interconnected systems with input and state delays using decentralized adaptive state observers

Abstract

This paper investigates the problem of decentralized model reference adaptive control (MRAC) for a class of large scale interconnected systems with both state and input delays. The upper bounds of the interconnection terms are considered to be unknown. Time varying delays in the nonlinear interconnection terms are bounded and nonnegative continuous functions and their derivatives are not necessarily less than one. For exact prediction, a decentralized adaptive state observer is designed and a nested predictor based approach is established to predict the future states of the input delay compensation. It is shown that the solutions of uncertain large‐scale time‐delay interconnected systems converge uniformly exponentially to a desired small ball. The effectiveness of the proposed approaches is illustrated by two examples.

A Characterization of approximate decentralized fixed modes of time‐delay systems

“…Many control systems, especially large-scale control systems, include time-delays due to, e.g., the transport phenomena, online data processing, required time to acquire information needed for decision making, to create and execute control decisions (see, e.g., [15][16][17]). With the development of computational tools, the subject of decentralized control of time-delay systems has seen a growing interest in the last decade (e.g., [18][19][20][21]). Considering decentralized systems with multiple time-delays, ADFMs are only briefly addressed for retarded time-delay systems in Momeni et al [3] where the results are the expansion of the results obtained in Davison and Aghdam [2] to the retarded time-delay systems.…”

Adaptive dynamic programming‐based decentralized event‐triggered control of large‐scale nonlinear systems

“…In general, interconnections coupled by subsystems pose big challenges to design the control approaches for large‐scale systems because they often have negative effect on system performance and may even lead to system instability [1‐3]. Therefore, more and more attention has been paid on how to design effectively optimal controllers to achieve good performance for interconnected large‐scale systems [4,5].…”

“…In general, interconnections coupled by subsystems pose big challenges to design the control approaches for large-scale systems because they often have negative effect on system performance and may even lead to system instability [1-3]. Therefore, more and more attention has been paid on how to design effectively optimal controllers to achieve good performance for interconnected large-scale systems [4,5].Different control strategies have been developed to address interconnected large-scale systems, which are broadly categorized into centralized control, distributed control and decentralized control. The classical centralized control requires information of all subsystems and control integrity is dominated by the centralized controller, so it is impractical for the lack of errors tolerance and growing dimension of large-scale systems [6].…”

Observer‐based decentralized robust H∞ output tracking control with preview action for uncertain and disturbed nonlinear interconnected systems

“…This has resulted in the development of various concepts and methodologies such as decentralized control theory, linear matrix inequality, and robust H ∞ optimization methods and techniques. The advantages and performance of these methods have been validated in actual interconnected control systems, including communication networks, chemical reactors, power systems, and ecosystems (see previous works [1–3] and the references therein). Generally, an interconnected system is composed of several local subsystems with evident interconnections.…”