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In this paper, the disturbance rejection adaptive fault-tolerant constrained consensus problem of multi-agent with actuator failures is investigated. At first, an auxiliary variable based observer is designed to estimate the disturbance. Then, based on the estimated disturbance, an adaptive law is provided for partial failures. In order to avoid the zero initial condition in the traditional $H_{\infty }$ control approach, a novel performance function is constructed with the considered initial condition. After this, a disturbance rejection adaptive fault-tolerant constrained consensus algorithm is given with the performance requirement. Finally, a simulation example is provided to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper aims to design an asynchronous adaptive fault-tolerant controller for the networked stochastic unmanned surface vehicles (NSUSVs) subject to multiple types of actuator faults and external disturbance. The partial fault and bias fault of the actuator are taken into consideration simultaneously. By estimating online the unknown bias fault of the actuator and the external disturbances, the proposed adaptive fault-tolerant controller can automatically compensate for these impacts produced by actuator faults and external perturbation while preserving the uniformly ultimate boundedness of the solutions. Both the faulty actuator and the designed controller are asynchronous with the NSUSVs. Moreover, a mode-dependent adaptive event-triggered mechanism (AETM) is introduced in order to facilitate network resources utilization. Finally, the effectiveness and correctness of the proposed design scheme are verified by a numerical example. [ABSTRACT FROM AUTHOR]

This article investigates an asynchronous adaptive fault-tolerant control problem for Markov jump systems (MJSs) with actuator failures and absolutely unknown nonlinear disturbances. The hidden Markov model (HMM) is used to describe the asynchronization phenomenon between the controller and the modes of the original system. Moreover, by using the designed adaptive law, the values of actuator partial failures and the bounds of the unknown nonlinear disturbances can be estimated, respectively. Furthermore, the HMM-based asynchronous adaptive fault-tolerant controller is provided to ensure that the closed-loop system is asymptotically stable despite of unknown nonlinear disturbances. Finally, numerical examples are given to show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Summary: In this paper, mixed passive / H∞ hybrid controllers are designed for a delayed Markovian jump system with actuator constraints and alarm signal. The actuator constraints include the unknown actuator bias failure and the actuator partial failure, and the controllers are switched by using alarm signals. First, a sufficient condition for mixed passive / H∞ performance of the closed‐loop system is constructed, and robust controllers and fault‐tolerant controllers are designed, respectively. Then, mixed passive / H∞ observers are presented to ensure that the actuator bias failure is well estimated. Next, an alarm system is proposed by designing multiple thresholds to avoid false alarm, and this system is used to invoke suitable controllers and determine whether to remove the estimated value of actuator bias failure. Finally, two numerical examples are given to illustrate the effectiveness of the method. [ABSTRACT FROM AUTHOR]

In this study, the synchronisation problem of bilateral teleoperation systems with time‐delay and actuator faults is considered. First, the error dynamic system with actuator faults is modelled as a time‐delay system with disturbance, and a fuzzy disturbance observer (FDO) is designed to estimate the unknown non‐linear disturbance. Moreover, an FDO‐based robust controller is provided for the master robot and a reliable controller is designed for the slave robot, respectively. Next, a sufficient condition is given to ensure the tracking error; the disturbance observation error and the parameter error are uniformly ultimate bounded. Finally, a numerical example is shown to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of exponential synchronization of discrete-time neural networks with mixed time delays, actuator saturation and failures. Meanwhile, the unreliable communication links are considered between the neural networks, and such unreliable links are modeled as stochastic missing data satisfying Bernoulli distributions. In order to show the relationships between actuator constraints, unreliable communication link and mixed delay neural networks, by using Lyapunov functional approach, a missing data probability dependent exponential synchronization criterion is given. Then, based on such criterion, a reliable controller is designed to ensure that the neural networks are exponentially synchronized in the mean square. Finally, a numerical example is provided to illustrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

In this paper, the problem of reliable bumpless transfer control for switched systems with actuator faults is investigated. A switching law and a class of reliable controllers via output feedback are constructed such that the bumpless transfer performance and H∞\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$H_\infty $$\end{document} reliable property of the closed-loop systems are guaranteed. The switching process is divided into two stages, that is, dwell time and state-dependent switching stages. In the dwell time stage, a low bound of the time of the activated subsystem is introduced to restrict the frequent switching and suppress the system bumps. This guarantees the bumpless transfer performance of systems. In the second stage, only the measurable controller states are used to generate the switching signals, which upgrades the feasibility in the frame of output feedback. Finally, to ensure the H∞\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$H_\infty $$\end{document} reliable property, the proposed controllers are time-varying, which work in the different switching stages. A simulation example is given to demonstrate the effectiveness of the proposed control scheme. [ABSTRACT FROM AUTHOR]