Observer-Based Event-Triggered Fault Tolerant MPC for Networked IT-2 T-S Fuzzy Systems

In this paper, a model predictive control scheme is developed for networked interval type-2 (IT-2) Takagi-Sugeno (T-S) fuzzy systems. To prevent the excessive use of bandwidth, the controller is designed in an event-trigger manner. However, the event conditions often require the transmission of all system states, imposing a substantial demand on network bandwidth; on the other hand, they are subject to network delay and packet loss. For this reason, in the existing approaches, event-triggered mechanisms primarily deployed in close proximity to the plant, or observer-based structures are used to enhance flexibility for implementing the controller. However, a common limitation in all these solutions is the assumption of network links being ideal, or at the very least, not accounting for all network-related limitations. The occurrence of faults is also an inevitable factor that has been overlooked in most related methods. To resolve this issue, a more comprehensive framework for event-triggered controllers is proposed in this paper in which an adaptive fuzzy observer is embedded, and the effects due to delay and packet loss are included in this observer. In addition, by developing an adaptive fault estimator and the introduction of a compensator term into the observer and controller formulations, a fault-tolerant performance of the event-triggered mechanism along with the controller is provided. These features enable the possibility of implementing the event-triggered mechanism next to the controller and at any desired distance from the plant, which resolves a serious concern in this area. Another important challenge considered in this work is ensuring the optimal performance of the controller in the entire prediction horizon. Also, the stochastic stability of the closed-loop system is proved such that defined H2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{H}}_{2}$$\end{document} and H infinity\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{H}}_{\infty }$$\end{document} performance indices are satisfied. Finally, the proposed control approach is evaluated using numerical and practical examples.