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The issue of cluster synchronization and disturbance rejection of multi‐weighted complex dynamical networks subject to nonlinearities and external disturbances are studied in this article. In particular, a hybrid‐triggering control scheme is implemented to mitigate the burden of the network transmission according to the prespecified triggering condition, under which each node will transmit its signal independently to the controller. To be more specific, a Bernoulli distributed stochastic variable is introduced to describe the switching law of the communication scheme. Also, the disturbance rejection performance is carried out with the aid of an improved equivalent input disturbance estimator approach. The sufficient criterion in the form of linear matrix inequalities is derived by constructing a suitable Lyapunov–Krasovskii functional and employing stochastic theory. Based on these settings, the feedback gain matrices and the trigger parameters affirming the desired cluster synchronization performance of the considered networks are established. Eventually, two illustrative examples including Lur'e networks with simulations are presented, which evidently proves the effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

Summary: This paper proposes a novel distributed stochastic routing strategy using mobile sink based on double Q‐learning algorithm to improve the network performance in wireless sensor network with uncertain communication links. Furthermore, in order to extend network lifetime, a modified leach‐based clustering technique is proposed. To balance the energy dissipation between nodes, the selected cluster head nodes are then rotated based on the newly suggested threshold energy value. The simulation results demonstrate that the proposed algorithms outperform the QWRP, QLMS, ESRP and HACDC in terms of network lifetime by 18.33%, 35.1%, 39.7% and 44.7%, respectively. Moreover, the proposed algorithms considerably enhances the learning rate and hence reduces the data collection latency. [ABSTRACT FROM AUTHOR]

With the assistance of reliable control technique, the nonfragile tracking problem has been proposed in this paper for a class of switched systems with external disturbances under the aegis of modified repetitive controller. Notably, the designed repetitive controller is used to improve the tracking performance of the addressed switched systems. Preciously, the influence of external disturbances are estimated through the improved equivalent‐input‐disturbance strategy, wherein the effect caused by the external disturbances to the output channel are reduced by the aid of modified repetitive control strategy. The fundamental intention of this control synthesis is that the output of the system precisely tracks the reference signal even in the presence of external disturbances and gain fluctuations. For that cause, Lyapunov stability technique in conjunction with average dwell time approach is implemented to obtain adequate conditions in the shape of linear matrix inequalities which insists the exponential stability for the addressed system. Ultimately, the efficiency and supremacy of the proposed control schemes are justified via two numerical examples, wherein it is exposed to view that the developed control strategy is capable of good tracking performance and also estimates the external disturbances efficiently. [ABSTRACT FROM AUTHOR]

A Hopfield neural network system with discrete (or variable delays) is considered in this paper. The standard assumption of Lipschitz continuity of the activation functions is dropped partially. Having in mind that this condition is needed not only for the uniqueness of solutions but also for the stability of the system, the present work improves the existing ones in the literature. The other feature here, which is in fact the main one, is the treatment of time‐dependent activation functions. The time‐independent case has been discussed by one of the authors in Tatar (2020). Unfortunately, it is not applicable to the present situation. Indeed, when applied, it will require a uniform boundedness condition. To overcome this difficulty, we provide here a new argument in addition to the introduction of some functionals. [ABSTRACT FROM AUTHOR]

The present study examines the state tracking problem of periodic piecewise polynomial systems subject to multiple disturbances and actuator faults. Specifically, the fundamental period is partitioned into several subintervals and the piecewise matrix polynomial functions can be put together to approximate the dynamics over each period, which are characterized by Bernstein polynomials. Moreover, the system dynamics contains both matched and mismatched disturbances, wherein the matched disturbance is unknown and resulted from some exogenous system, and mismatched case is norm‐bounded. The control law is configured by integrating the output of the disturbance observer with state‐feedback reliable control law. Particularly, a disturbance observer is designed to estimate the disturbance caused by an exogenous system. Besides, by considering time‐varying polynomial Lyapunov function and making use of Bernstein polynomial approach, a set of sufficient conditions is derived which are expressed in terms of linear matrix inequalities. Further, by virtue of MATLAB software the desired controller and observer gain matrices can be computed. In conclusion, the potential and significance of the theoretical findings are confirmed by presenting a numerical example with simulation results. [ABSTRACT FROM AUTHOR]

Summary: The bipartite tracking control problem for a class of multi‐agent system under the influence of faults is addressed in this article by using the memory‐feedback control approach. In particular, an undirected structurally balanced signed network graph is used to express the cooperative and antagonistic communication between neighboring agents. In order to reach the desired bipartite tracking performance as well as to estimate the unified unknown input of the leader and the fault signal, a novel intermediate estimator is proposed. Using appropriate Lyapunov–Krasovskii functional the required constraints that ensure the bipartite tracking performance of the considered multi‐agent system are developed in terms of linear matrix inequalities. The required memory‐feedback controller and intermediate estimator gain parameters are obtained by solving the set of linear matrix inequality constraints. At last, simulation examples are given to exhibit the efficacy of the developed theoretical results. [ABSTRACT FROM AUTHOR]

Summary: This study focuses on the guaranteed cost control problem for interval type‐2 stochastic fuzzy coupled neural networks (NNs) elicited by the observer framework with Markov switching topology, external disturbances, and quantization effect. In particular, the guaranteed cost controller is developed with an upper bound of the guaranteed cost function and also ensures stability of the addressed networks. Also, the integration of lower and upper membership functions are incorporated to relax the stability condition of the networks. Notably, the randomness phenomena are incorporated by the agency of stochastic variables that satisfies the Bernoulli distribution characteristics. Specifically, the state feedback controller considered with quantization effect is designed through undirected communication graph subject to Markov switching topology. In consequence with Lyapunov–Krasovskii‐functional and algebraic graph theory, sufficient conditions are established to assure the stochastic stabilization of the NNs with some specified cost value. Explicitly, the optimal upper bound of the guaranteed cost function and the controller gain fluctuations of the state and the observer are effectuated through the developed conditions. Finally, the reduced conservatism and efficiency of the proposed analytical design are demonstrated through a numerical example. [ABSTRACT FROM AUTHOR]

Summary: An event‐triggered nonfragile distributed H∞ control problem is considered in this article for a class of uncertain nonlinear networked control systems over sensor networks with random communication packet dropouts and redundant channels. Redundant channel transmission is utilized to model the communication measurement and to improve the reliability and quality of the communication data transmission services. In addition, measurement size reduction technique is applied to reduce the energy consumption. An event based transmission scheme is employed to reduce the network burden and energy consumption during the data communication from the sensor to the estimator. With known conditional probability distribution, the random packet losses are modeled as a Bernoulli distributed white sequences. A new set of sufficient conditions is established by using average dwell time approach to obtain the desired observer‐based distributed nonfragile controller with the H∞ performance requirements. Specifically, the explicit form of an observer‐based feedback parameters can be obtained by solving a set of linear matrix inequalities. Finally, to demonstrate the effectiveness of the proposed observer‐based feedback approach, a numerical example is exploited. [ABSTRACT FROM AUTHOR]

Abstract: The problem of reliable sampled‐data control design for uncertain singular fuzzy system with randomly occurring delay and nonlinear actuator failures is studied in this paper. The fault model is composed of two parts in which, linear part stands for the gain missing of actuators that vary with the true control input linearly, while the nonlinear part indicates some bounded nonlinear variation. Moreover, the time delay which encountering in the proposed controller is assumed to be randomly varying and satisfies Bernoulli distributed probabilities. By constructing a proper time‐dependent Lyapunov functional, some novel sufficient conditions are derived in terms of linear matrix inequalities (LMIs) for the existence of robustly stochastically stabilizing reliable sampled‐data controllers. Two simulation examples are given to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper is concerned with the observer-based output tracking problem for a class of linear switched stochastic systems with time delay and disturbance by using repetitive control approach. More precisely, a two-dimensional hybrid model is incorporated to obtain and optimize the repetitive controller. In particular, the repetitive controller is used to improve the tracking performance through its continuous learning actions. In addition, an equivalent-input-disturbance estimator is incorporated into the repetitive control design approach to reduce the effect of the external disturbances. The main aim of the control design is to track the periodic reference signal with the measured output of the system under consideration even in the presence of an unknown bounded disturbance. By constructing a suitable Lyapunov-Krasovskii functional and using average dwell time approach and Jensen inequality, sufficient conditions are obtained in terms of linear matrix inequalities to guarantee the mean-square exponential stability of the considered system. Eventually, a numerical example is provided to demonstrate the effectiveness of the developed method. [ABSTRACT FROM AUTHOR]

In this paper, the problem of H ∞ filtering for impulsive networked control systems with random packet dropouts and randomly occurring nonlinearities is investigated. By utilizing an impulsive model, the network-induced imperfections including packet dropout and delay are described by the Bernoulli distributed sequence. The delay in the model is assumed to be time varying. Moreover, nonlinearity in the model is assumed to satisfy sector-like nonlinearities. The H ∞ filter is designed by using the linear matrix inequality (LMI) approach and convex optimization technique. The filter gain matrices for the nonlinear networked control systems can be achieved by solving LMIs, which can be easily facilitated by using some standard numerical packages. Finally, a numerical example is presented to demonstrate the effectiveness and applicability of the proposed results. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]