Asynchronous Phenomena Research Articles

Dynamic‐memory event‐based asynchronous security control for positive singular semi‐Markov jumping CPSs against multiple cyber‐attacks

AbstractThis paper mainly studies the design of asynchronous controllers for positive singular semi‐Markov jump systems with performance under the dynamic‐memory event‐triggered. The positive singular semi‐Markov jump system model is established for the first time. And the dynamic‐memory event‐triggered transmission protocol is used to reduce network transmission pressure. Then, a unified cyber‐attack framework that includes DoS attacks and spoofing attacks is established. A simple hidden Markovian model (HMM) model is used to describe the asynchronous phenomena between the controller and the system. Considering the situation where all data cannot be accurately obtained in reality, a simple HMM is set as a partially unknown conditional probability matrix. Based on stochastic Lyapunov functional, the stochastically admissible conditions for the closed‐loop systems are obtained. Finally, a numerical example is given to verify the effectiveness of the proposed method.

Security dissipative control for interval type‐2 fuzzy hidden Markovian jump systems under event‐triggered scheme

AbstractThis article presents a new design approach for resilient fault‐tolerant event‐triggered (ET) based security control of Markovian jump nonlinear systems (MJNSs) in the presence of nonperiodic denial‐of‐service (DoS) attacks. The approach is developed based on interval type‐2 (IT‐2) fuzzy models of the plant. The state error produced by data packet loss is turned into a parameter in the proposed ET condition during nonperiodic DoS attacks. The uncertain triggering variable is considered in the resilient fault‐tolerant ET condition for the MJNSs. In contrast to the usual strategy, the fault‐tolerant ET strategy is designed to send the required data packets to the controller during nonperiodic DoS attacks, which significantly contributes to the minimization of performance loss. Dissipative, passive, and ‐control schemes are all covered in a unifying framework by using a generalized performance index. Plant and controller modes are considered under mismatched membership functions to regulate asynchronous phenomena. Sufficient conditions depending on the membership functions that guarantee the stability of the closed‐loop system are derived. Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed approach.

Guaranteed cost extended dissipative stabilization of switched IT2 fuzzy systems via intermittent control and its applications

This paper deals with the guaranteed cost extended dissipative stabilization problem of switched IT-2 fuzzy systems (SFSs) via intermittent control. Firstly, we propose a new class of system performance coefficients, taking both the extended dissipative performance and quadratic cost function performance into account. Then, by using a switched-path-dependent fuzzy Lyapunov functions (SFLFs) approach, the membership-function-shape-dependent (MFSD) existence conditions of a set of intermittent controllers are established. Furthermore, we apply the designed intermittent control scheme to three practical control problems: 1) A controller/actuator-failure-triggered intermittent controller is designed, and the guaranteed cost extended dissipative performance of SFSs is ensured in the presence of controller/actuator failures; 2) A switching-triggered intermittent controller is designed, and the guaranteed cost extended dissipative performance of SFSs is ensured in the presence of transmission delay of switching signal, and the asynchronous phenomena is eliminated; 3) A hybrid-triggered intermittent controller is designed, and the guaranteed cost extended dissipative performance of SFSs is ensured while the control resources are saved. Finally, the effectiveness of the results are demonstrated through a robot arm model.

Hidden Markov Model-Based Control for Cooperative Output Regulation of Heterogeneous Multi-Agent Systems under Switching Network Topology

This paper investigates the problem of stochastically cooperative output regulation of heterogeneous multi-agent systems (MASs) subject to hidden Markov jumps using observer-based distributed control. In order to address a more realistic situation than prior studies, this paper focuses on the following issues: (1) asynchronous phenomena in the system mode’s transmission to the controller; (2) the impact of system mode switching on network topology; and (3) the emergence of coupled terms between the mode-dependent Lyapunov matrix and the control gain in control design conditions. Specifically, to reduce the complexity arising from the asynchronous controller-side mode, the leader–state observer is developed so that the solution pair of regulator equations can be integrated into the observer. Furthermore, a linear decoupling method is proposed to handle the emergence of the aforementioned coupled terms; this provides sufficient LMI conditions to achieve stochastically cooperative output regulation for heterogeneous MASs. Finally, the validity of the proposed method is shown through two illustrative examples.

Dual asynchronous control for T‐S fuzzy semi‐Markov jump systems: A finite‐time design

AbstractThis paper addresses the control problem of Takagi–Sugeno fuzzy semi‐Markov jump systems (TFSMJSs) under the finite‐time analysis and synthesis framework. Due to the commonly used networked communication structure, the semi‐Markovian jumping modes and fuzzy premise variables cannot always perfectly match for system and controller among the whole system operation. More precisely, both asynchronous phenomena in fuzzy membership and jumping mode are taken into account, and then, mode‐dependent finite‐time controllers are developed with these features. By utilizing stochastic analysis and Lyapunov–Krasovskii stability theory, sufficient criteria are first established for the closed‐loop system in the context of mean‐square sense. Furthermore, feedback controller gains are captured by the matrix technique and parallel distributed compensation (PDC)‐related arguments. Eventually, a simulation example of an unmanned marine vehicle (UMV) is utilized to demonstrate the validity of the developed results.

Composite event‐triggered H∞ control for nonlinear switched singular systems with a mode‐dependent triggering strategy

SummaryThis paper considers the event‐triggered control problem of nonlinear switched singular systems (NSSSs) with incremental quadratic constraints (IQCs) via a mode‐dependent hybrid triggering strategy. First, impulsive control is introduced to reduce the effect of impulse caused by switching, and the closed‐loop system is modeled as an impulsive NSSS. Then, a novel mode‐dependent hybrid event‐triggering strategy (ETS) consisting of disturbance‐influenced ETS and Lyapunov‐function‐dependent ETS is constructed to avoid Zeno behavior and asynchronous phenomena. Based on this ETS and admissible edge‐dependent average dwell time (AED‐ADT) method, some new sufficient conditions in terms of linear matrix inequalities (LMIs) are derived to ensure that the closed‐loop system is regular, impulse‐free, has a unique solution, and is globally uniformly asymptotically stable (GUAS) with a weighted performance. Further, Zeno behavior is excluded by calculating the minimum lower bound of inter‐event time. Finally, a numerical example and a practical application are proposed to demonstrate the validity of the results.

Transient behaviors of the pulsating dissipative solitons in a net normal-dispersion fiber laser

As one of the universal phenomena in diverse fields, pulsating solitons exhibit charming and complex transient behaviors. Herein, based on the dispersive Fourier transform technique, three typical types of dissipative soliton pulsations are unveiled in a net normal-dispersion mode-locked fiber laser. According to their different oscillation modes, they are divided into single-period soliton pulsation, double-period soliton pulsation and asynchronous soliton pulsation. In particular, for the double-period soliton pulsation, the pulse shape repeats itself after two pulsations. Moreover, for asynchronous soliton pulsation, the dual-soliton evolve at different rates during the pulsation process, leading to the appearance of asynchronous phenomena. The findings will provide new insights into the complex mechanisms of soliton pulsation in fiber lasers and nonlinear dissipative systems.

Memristive FHN spiking neuron model and brain-inspired threshold logic computing

The FitzHugh-Nagumo (FHN) spiking model has rich dynamics behaviors and can imitate the firing process of a neuron. The memristor is a nonvolatile and resistance tunable device, which gradually becomes a potential candidate for performing dynamic behaviors and implementing neuromorphic computation in the nervous system. In this paper, the memristive FitzHugh-Nagumo (MFHN) spiking model is presented. Firstly, we introduce a memristor to the FHN spiking model to build the MFHN spiking model and analyze the phase plane trajectory of the MFHN model. Secondly, we couple two MFHN models with a memristor and experimentally simulate the dynamic behaviors of two coupled neurons. The synchronous and asynchronous phenomena of two coupled neurons are discussed. Thirdly, the feasibility of the MFHN spiking model is demonstrated by the realization of binary logical operations and the implementation of binary adders. The comparison between the MFHN binary adder and the FHN binary adder is conducted. The simulation results illustrate that the proposed model efficiently performs rich, dynamic behaviors and higher firing frequency. The coupled MFHN models show the effectiveness of a memristor acting as an electric coupling synapse. The threshold logic computation can be completed efficiently by the MFHN spiking model. The MFHN binary adders reproduce the computing functions and behaviors of the biological neuron.

Interval Type-2 Fuzzy Control for HMM-Based Multiagent Systems via Dynamic Event-Triggered Scheme

This article discusses the interval type-2 (IT2) Takagi–Sugeno (T-S) fuzzy asynchronous controller design problem for nonlinear multiagent systems via a dynamic event-triggered scheme in the discrete-time context. To formulate the asynchronous phenomena between the system modes and the anticipant controller modes, the hidden Markov model is proposed. The primary attention is focused on the explicit design of the dynamic event-triggered strategy that can be dynamically adjusted in line with system information, which mitigates the communication burden efficiently. On this occasion, the information renewal of the controller is aperiodic. Furthermore, the nonlinear characteristics are effectually disposed through utilizing a unique IT2 T-S fuzzy model, which is with mismatched membership functions (MFs). As a result, the resulting closed-loop fuzzy multiagent systems are accompanied by mismatched MFs and asynchronous modes, whereafter, via solving the convex optimization problem, the desired controller gains are acquired. Eventually, the validity and practicability of the developed control scheme are illustrated by two examples.

Transient Response and Firing Behaviors of Memristive Neuron Circuit.

The signal transmission mechanism of the Resistor-Capacitor (RC) circuit is similar to the intracellular and extracellular signal propagating mechanism of the neuron. Thus, the RC circuit can be utilized as the circuit model of the neuron cell membrane. However, resistors are electronic components with the fixed-resistance and have no memory properties. A memristor is a promising neuro-morphological electronic device with nonvolatile, switching, and nonlinear characteristics. First of all, we consider replacing the resistor in the RC neuron circuit with a memristor, which is named the Memristor-Capacitor (MC) circuit, then the MC neuron model is constructed. We compare the charging and discharging processes between the RC and MC neuron circuits. Secondly, two models are compared under the different external stimuli. Finally, the synchronous and asynchronous activities of the RC and MC neuron circuits are performed. Extensive experimental results suggest that the charging and discharging speed of the MC neuron circuit is faster than that of the RC neuron circuit. Given sufficient time and proper external stimuli, the RC and MC neuron circuits can produce the action potentials. The synchronous and asynchronous phenomena in the two neuron circuits reproduce nonlinear dynamic behaviors of the biological neurons.

Input‐to‐state stability for discrete‐time time‐varying impulsive switched delayed systems with asynchronous phenomena

AbstractThis paper studies the input‐to‐state stability (ISS) for a class of discrete‐time time‐varying impulsive switched delayed systems, in which the asynchronous phenomena are considered. Asynchronous phenomena here include two implications: asynchronous impulses and switches and asynchronous switching. The former means that the events, that is, impulses and switches, are not necessary to occur simultaneously, while the latter indicates that the actual switching modes and related controllers or specified modes do not coincide. Applying the mode‐dependent concept to impulses and switches, both the improved Krasovskii‐type and Razumikhin‐type ISS criteria are provided. The time differences of Lyapunov functionals or functions here are sign‐changing and time‐varying, releasing from the traditional assumption that always requires negative definiteness. Meanwhile, in this paper, ISS or non‐ISS subsystems and stabilizing or destabilizing impulses are taken into account. Finally, three numerical examples are given to illustrate the effectiveness of the proposed results.

Asynchronous filtering for Markov jump systems within finite time: A general event-triggered communication

In this paper, an event-based asynchronous H∞ filter design method for Markov jump systems over a finite-time interval is proposed. First, the hidden Markov model with a known conditional probability matrix is introduced to describe the asynchronous phenomena due to the failure of precisely obtaining the system mode information. Accordingly, an asynchronous event-triggered transmission strategy with a general threshold is presented to availably save the communication costs. Then, via using the mode-dependent Lyapunov function, a full-order filter regulated by the event-triggered strategy is established to track the system outputs. Based on Finsler’s lemma, sufficient conditions with less conservatism are deduced such that the resulting system is stochastically finite-time bounded while satisfying prescribed H∞ performance. Finally, a simulation example is implemented to illustrate the effectiveness of the theoretical results.

Energy-to-Peak State Estimation for Switched Neutral-Type Neural Networks With Sector Condition via Sampled-Data Information.

In this article, the energy-to-peak state estimation problem is investigated for a class of switched neutral neural networks subject to the external perturbations with bounded energy. Both the values of the measurement outputs and switching signal of the subsystems are only available for the controllers at the discrete sampling instants. Unlike the results for nonswitched neural networks, the coexistence of the switching and sampling actions directly causes the asynchronous phenomena between the indexes of subsystems and their corresponding controllers. To address this situation, the piecewise time-dependent Lyapunov-Krasovskii functional and slow switching mechanism are introduced. Under the developed theorem conditions, we prove that the designed state estimator exponentially tracks the true value of the neural state with the accessible sampled-data information. Also, the influence of the exogenous perturbations on the peak value of the estimation error is constrained at a prescribed level. Finally, a neutral cellular neural network with switching parameters is employed to substantiate the effectiveness and applicability of the theoretical results.

Asynchronous l 2 – l ∞ filtering of discrete-time impulsive switched systems with admissible edge-dependent average dwell time switching signal

In this paper, the asynchronous filtering problem is directed at a kind of discrete-time impulsive switched systems, where ‘asynchronous’ implies that there is a delay when switching occurs between filter modes and system modes. A novel Lyapunov function has been constructed. The inventiveness lies in discontinuity of Lyapunov-like function at both the switching time and the instant when the system modes and filter modes are matched. An improved inequality portraying the relationship among Lyapunov-like function, impulse, asynchronous phenomena and disturbance is built to pledge the performance. On the basis of directed graph, the novel Lyapunov function, the improved inequality and admissible edge-dependent average dwell time technology, some criteria suitable for proving the globally uniformly exponential stability of filtering error system are proposed with performance index, and the relevant filter can also be designed. Finally, three numerical examples show the availability of the obtained conclusions.

Dissipativity-based asynchronous control for discrete-time singular Markov jump systems with multiplicative noises

The singular systems, which could widely describe more general systems and present traits of physical features, are discussed in this study. Taking the fact that noises always exist in the state and output measurement of one singular system into consideration, which may cause some errors and decrease system performance, this article devotes itself to the dissipative control for discrete-time singular Markov jump systems (SMJSs) with multiplicative noises. To deal with the asynchronous phenomena between the system modes and the controller modes, a set of Markov chains are constructed. To make sure the closed-loop singular system is dissipative, a set of sufficient conditions are derived based on the linear matrix inequalities, and then the asynchronous controller is designed to ensure that SMJSs are stochastically admissible and strictly dissipative. Finally, a simulation example is carried out to verify the correctness of the derived theorem. The designed asynchronous controller improves the robustness of the controller and overcomes the asynchronous phenomenon. This control method can be applied in the fields of robot control system.

H∞ control design for discrete-time switched fuzzy systems

This paper investigates the H∞ control design and asynchronous stabilization problems for a class of discrete-time switched Takagi and Sugeno (T–S) fuzzy systems. The studied fuzzy systems have two level functions, namely, crisp switching functions and local fuzzy weighting functions, which inherently contain the features of switched hybrid systems and T–S fuzzy systems. In addition, the considered switching instants have asynchronous phenomena between the system switching modes and the controller switching modes. Based on the theory of the switching Lyapunov stability and average-dwell time method, both the matched H∞ state feedback controllers and the unmatched state feedback controllers are designed. Moreover, the global uniformly asymptotically stability (GUAS) conditions are proposed and formulated in the form of linear matrix inequalities (LMIs). An illustrated numerical example is provided to show the effectiveness of the obtained theoretical results.

The Exponential Stability and Asynchronous Stabilization of a Class of Switched Nonlinear System Via the T–S Fuzzy Model

In this paper, we investigate the problem of exponential stability and asynchronous stabilization for a class of switched nonlinear systems. The Takagi and Sugeno (T-S) fuzzy model is employed to approximate the subnonlinear dynamic systems. With two-level functions, namely, crisp switching functions and local fuzzy weighting functions, we introduce continuous-time switched fuzzy systems, which inherently contain the features of the switched hybrid systems and T-S fuzzy systems. By the use of delicately constructed piecewise Lyapunov-like functions (PLFs) and minimum dwell time method, we obtain the exponential stability of the switched fuzzy systems, which allows us to have stable and unstable nonlinear subsystems. In practice, for the control problem, it inevitably takes some time to identify the system modes and apply the matched controller, the asynchronous phenomena between the system modes switching and the controllers switching generally exists. Based on the result of stability, the fuzzy state feedback controller under asynchronous switching is proposed for switched fuzzy systems. In addition, the lower bound of minimum dwell time can be obtained using convex optimization such that the switched fuzzy system can be exponentially stabilized if its minimum dwell time is larger than the bound. The stability results and control laws of the switched fuzzy systems are formulated in the form of linear matrix inequalities that are numerically feasible. Finally, two illustrated numerical examples are presented to show the effectiveness of the obtained theoretical results.

Exponential Stability and Asynchronous Stabilization of Switched Systems With Stable and Unstable Subsystems

AbstractThis paper deals with the exponential stability and asynchronous stabilization of continuous‐time switched systems. By delicately constructed piecewise Lyapunov‐like functions and the minimum dwell time switching method, exponential stability of the switched systems with stable or unstable subsystems is obtained. Based on the result of the stability, the problem of controller design of the switched systems under asynchronous switching is also solved, and the delay that causes asynchronous phenomena can be unbounded. The stability results and control laws of the switched systems are formulated in the form of linear matrix inequalities that are numerically feasible. Finally, two illustrative numerical examples are presented to show the effectiveness of the obtained theoretical results.

Research on Start-up Time of the Supply Chain Emergency Plan Based on Online Method

This paper researches the optimal start-up time of emergency plan adopting online method. In view of this problem, it establishes respectively mathematical models of the single enterprise and the simple supply chain enterprises. And then competitive ratio is introduced to illustrate the effectiveness of start-up strategies. When the whole supply chain enterprises are considered as the research objective, the time asynchronous phenomena when launching the preplan appear between the single enterprise and the whole supply chain. Aimed at this phenomenon, it puts forward coordination mechanism, realizes the optimal response of the whole supply chain for emergencies, and controls the loss emergencies causes to the minimum. The research result has theoretical guidance and practical application value.

Grouping Synchronization in a Pulse-Coupled Network of Chaotic Spiking Oscillators

This paper studies a pulse-coupled network consisting of simple chaotic spiking oscillators (CSOs). If a unit oscillator and its neighbor(s) have (almost) the same parameter values, they exhibit in-phase synchronization of chaos. As the parameter values differ, they exhibit asynchronous phenomena. Based on such behavior, some synchronous groups appear partially in the network. Typical phenomena are verified in the laboratory via a simple test circuit. These phenomena can be evaluated numerically by using an effective mapping procedure. We then apply the proposed network to image segmentation. Using a lattice pulse-coupled network via grouping synchronous phenomena, the input image data can be segmented into some sub-regions.