Observer-Based Adaptive Event-Triggered Control for Nonlinear Networked Systems Under Multiple Cyber Attacks

This article is focused on the problem of adaptive event-triggered (AET)-based security controller construction for nonlinear networked control systems (NCSs) under multiple network attacks, which are represented by interval type-2 (IT-2) fuzzy models. Firstly, in an attempt to mitigate the communication load, an enhanced adaptive event-triggered mechanism (AETM) is utilized for determining the signals' transmission order, which is capable of adjusting the threshold dynamically with the signals probabilistically subjected to occurring malicious attacks. In addition, the observer is constructed under unfathomable premise variables, and then the controller with imperfect matching membership functions (MFs) is created based on the estimated states, which is homogenous polynomially parameterdependent. Moreover, the observer-based controller is obtained for the asymptotic stability with an H∞ performance index via the Lyapunov stability theory. Then, sufficient conditions for the appropriate observer and controller gain matrices are given based on the linear matrix inequality method. Subsequently, the reliability of the proposed observer-based security fuzzy control design approach is demonstrated by two numerical simulation examples.