Event-driven intermittent control

An intermittent controller with fixed sampling interval is recast as an event-driven controller. The key aspect of intermittent control that makes this possible is the use of basis functions, or, equivalently, a generalised hold, to generate the intersample open-loop control signal. The controller incorporates both feedforward events in response to known signals and feedback events in response to detected disturbances. The latter feature makes use of an extended basis-function generator to generate open-loop predictions of states to be compared with measured or observed states. Intermittent control is based on an underlying continuous-time controller; it is emphasised that the design of this continuous-time controller is important, particularly in the presence of input disturbances. Illustrative simulation examples are given.     

The system-matched hold and the intermittent control separation principle

An intermittent controller is a form of hybrid controller which adds a generalised sample and hold mechanism to an underlying continuous-time feedback control system. The sampling may be non-uniform or event driven. One particular form of the hold, termed the system-matched hold (SMH) mimics the behaviour of the closed-loop feedback control signal during the intermittent intervals. It is shown in this article that this choice of hold leads to an intermittent separation principle. In particular, this simple analytical result ensures that when using the SMH, the separation properties of the underlying state-estimate feedback control system carry over to the intermittent control system. This separation principle for the SMH has the important consequence that, unlike the zero-order hold case, the stability of the closed-loop system in the fixed sampling case is not dependent on sample interval. It is therefore suggested that the SMH should replace the conventional zero-order hold in circumstances where the sample interval is unknown, time-varying or determined by events.     

Constrained intermittent model predictive control

The generalised hold formulation of intermittent control is re-examined and shown to have some useful theoretical and practical properties. It is shown that this provides a foundation for constrained model predictive control in an intermittent context. The method is illustrated using an example and verified with experimental results.     

Event-driven intermittent control for vehicle platooning over vehicular ad-hoc networks

This article is concerned with the problem of vehicle platooning control over vehicular ad-hoc networks (VANETs). Compared with the existing platooning control strategies, an event-driven intermittent control method is developed to reduce control costs and extend the operating life of controllers while ensuring the desired platooning performance. By establishing suitable boundary functions and Lyapunov function, the control input is determined according to the relationship among the trajectories of these functions. Thereafter, sufficient conditions for platooning control performance analysis are derived by a set of linear matrix inequalities. Wherein, the vehicle platooning based on intermittent control is obtained to maintain the desired inter-vehicle distance and a uniform speed in the platoon. Furthermore, a simple optimization algorithm is constructed to calculate the smallest upper bound on tracking errors. Finally, several simulations based on different topologies are provided to verify the validity of the proposed method.     

Consensus of multi-agent systems via intermittent event-triggered control

This paper addresses the consensus issue for multi-agent systems with fixed directed interaction topology, and each agent is supposed to have nonlinear dynamics. By introducing the event-triggered mechanism into intermittent control, suitable consensus protocols are provided, which can save communication resources and reduce the number of control updates. Based on the Lyapunov functional method and stability analysis for switching systems, both centralised and decentralised event-triggered strategies for consensus are proposed. Furthermore, the proof of Zeno behaviour being excluded is given. Finally, some numerical examples are shown to demonstrate the effectiveness of the theoretical results.     

时滞神经网络双周期间歇控制滞后同步

提出了一个时滞神经网络周期间歇控制滞后同步策略,其间歇控制周期为两个不同的周期。利用Lyapunov稳定性理论,证明了时滞神经网络在此控制策略下能够实现同步,并获得了同步解全局指数稳定的充分条件。给出了一个仿真实例验证了控制方案的有效性。     

时延复杂网络的自适应周期间歇同步控制

研究同时具有耦合时延和节点时延复杂网络的自适应周期间歇同步控制问题.运用 Lyapunov 稳定性理论,自适应控制、牵制控制和间歇控制方法,给出保证该时延复杂网络全局指数同步、且保守性更小的判定准则,并给出相应的自适应和牵制自适应间歇同步控制器设计,该控制策略对节点间的耦合强度和网络的拓扑结构等具有较强的鲁棒性.最后以时延非线性动力系统为节点对复杂网络进行数值仿真,验证了结论的正确性和有效性.     

Exponential stabilisation of memristive neural networks under intermittent output feedback control

In this paper, the exponential stabilisation problem is studied for a general class of memristive time-varying delayed neural networks under periodically intermittent output feedback control. First, the periodically intermittent output feedback control rule is designed for the exponential stabilisation of the memristive time-varying delayed neural networks. Then, we derive stabilisation criteria so that the memristive time-varying delayed neural networks are exponentially stable. By the mathematical induction method and constructing suitable Lyapunov–Krasovskii functionals, some easy-to-check criteria are obtained to ensure the exponential stabilisation of memristive time-varying delayed neural networks. Finally, two numerical simulation examples are given to illustrate the validity of the obtained results.     

Exponential synchronization of Cohen-Grossberg neural networks via periodically intermittent control

In this paper, a class of Cohen-Grossberg neural networks with time-varying delays are studied by designing a periodically intermittent controller. Some novel and effective exponential synchronization criteria are derived by applying some analysis techniques. These results generalize a few previous known results and remove some restrictions on control width and time-delays. Finally, a chaotic Cohen-Grossberg neural network is represented to show the effectiveness and feasibility of our results.     

Containment control for second-order nonlinear multi-agent systems with intermittent communications

This article investigates the containment control problem for a class of second-order multi-agent systems with inherent nonlinear dynamics, under the common assumption that each agent can only obtain the relative information of its neighbours intermittently. A kind of distributed protocol based only on the relative local intermittent measurements of neighbouring agents is designed for containment control under fixed directed topology. In the absence of delays, based on the Lyapunov function technology and the intermittent control method, some sufficient conditions are presented to guarantee the intermittent containment control of second-order nonlinear multi-agent systems. In the presence of delays, some containment conditions are also obtained for a second-order multi-agent systems with inherent delayed nonlinear dynamics and intermittent communications. Moreover, the similar results are obtained for second-order nonlinear multi-agent systems under switching directed topology. Finally, simulation examples are given to illustrate the correctness and effectiveness of the theoretical analysis.     

Exponential synchronization of inertial neural network with mixed delays via intermittent pinning control

This article considers the problem of exponential synchronization of inertial neural networks (INNs) with mixed delays via a novel hybrid control scheme consisting of pinning and periodic intermittent control. Both the discrete delay and distributed delay are taken into account in the network model. Through the proper variable substitution, the original system is transferred into a simply formed differential equation. Meantime, some new sufficient conditions are derived by the Lyapunov stability theory for the exponential synchronization of INNs. Eventually, numerical simulations are given to present the effectiveness of the theoretical method.     

基于间歇控制的不确定主从Lur’e系统的指数同步

研究了不确定主从Lur’e系统的问歇控制同步问题．运用Lyapunov稳定性理论和S-过程,首先推导出保证标称主从Lur’e系统指数同步的一个充分条件．在此基础上进一步得到了具有范数有界不确定性主从Lur’e系统鲁棒指数同步的结果．这些同步判据以矩阵不等式的形式给出．另外我们还提出了一种最小化性能指标的优化策略．最后,通过两个数值例子验证了结果的有效性．     

混沌系统的间歇控制及其在保密通信中的应用*

基于连续控制方法的混沌保密通信方案很容易被跟踪或者复制,大大限制了混沌在保密通信中的应用.采用不连续的周期间歇控制方法研究了混沌系统的同步和在保密通信中的应用问题;证明了在适当的控制条件下两个耦合的混沌系统达到精确同步,并给出一组设置控制周期和控制宽度的充分条件,数值模拟验证了理论结果的有效性.该不连续的控制方法可应用到混沌保密通信中,增加通信的保密性能.     

Adaptive aperiodically intermittent control for pinning synchronization of directed dynamical networks

In this paper, we investigate the pinning synchronization of directed complex network with time‐varying delay under the adaptive aperiodically intermittent control. First, the model of a directed complex network is established, the interaction graph of which is not required to contain a directed spanning tree, and for which an adaptive aperiodically intermittent feedback controller is well designed. In addition, based on the Lyapunov function method and linear matrix inequality technique, several asymptotical synchronization criteria are derived via an aperiodically intermittent strategy, which is superior to the periodical scheme. Moreover, the adaptive strategy providing the exponential convergence rate and the pinning algorithm demonstrating how to select pinned nodes are presented. Finally, numerical examples are provided to illustrate the effectiveness of the derived theoretical results.     

半主动控制接地式动力吸振器参数优化及性能比较

将半主动开关型控制策略应用到接地式动力吸振器中,并进行性能分析和参数优化.首先,利用平均法求得两种半主动接地式动力吸振器的近似解析解,并与相应数值解对比,验证了解析解的正确性与高精度.然后,对两种半主动控制接地式动力吸振器进行参数优化,获得系统最优控制结果和对应最优参数,确定了半主动控制最优控制策略,对影响优化结果的三个关键参数进行了特性分析.最后,和另外两种传统吸振器对比,用随机激励进一步验证了半主动开关位移-速度控制策略(On-off DBG)最为有效.     

Exponential synchronization of chaotic systems with stochastic noise via periodically intermittent control

The problem of second‐moment exponential synchronization is discussed for chaotic systems. Different from some existing results, a unified drive‐response system is formulated, which involves stochastic noise and the time‐varying delay. Meanwhile, the feedback controller is presented by the periodically intermittent control. By exploiting the Lyapunov stability theory, the improved reciprocally convex inequality and the Itô formula, several new sufficient conditions are obtained to make two systems synchronized. In addition, the controller is determined by the control period and the control width. Finally, simulation results illustrate that the designed controller achieves the desired performance.     

Synchronization of complex networks with coupling delays via adaptive pinning intermittent control

The problem of exponential synchronization for a class of general complex dynamical networks with nonlinear coupling delays by adaptive pinning periodically intermittent control is considered in this paper. We use the methods of the adaptive control, pinning control and periodically intermittent control. Based on the piecewise Lyapunov stability theory, some less conservative criteria are derived for the global exponential synchronization of the complex dynamical networks with coupling delays. And several corresponding adaptive pinning feedback synchronization controllers are designed. These controllers have strong robustness against the coupling strength and topological structure of the network. Using the delayed nonlinear system as the nodes of the networks, a numerical example of the complex dynamical networks with nonlinear coupling delays is given to demonstrate the effectiveness of the control strategy.     

Pinning synchronization of complex delayed dynamical networks via generalized intermittent adaptive control strategy

In this paper, the problem of pinning synchronization for delayed complex directed networks via generalized intermittent adaptive control strategy is considered. First, a dynamical mode of delayed network is investigated. Second, a generalized intermittent adaptive control strategy which unified the traditional periodic intermittent control and the aperiodic case is introduced. Additionally, by constructing a piecewise Lyapunov auxiliary function and making use of piecewise analysis technique, some effective and novel criteria to ensure the global synchronization of delayed complex networks based on the designed control protocols are obtained. Finally, an example with numerical simulations is provided to demonstrate the validness of the theoretical results proposed scheme.     

Semiglobal finite‐time synchronization of complex networks with stochastic disturbance via intermittent control

This paper focuses on the problem of semiglobal finite‐time synchronization of stochastic complex networks via an intermittent control strategy. By establishing a finite‐time criterion condition and a novel finite‐time ‐operator differential inequality, combined with convex techniques, some sufficient conditions are obtained to ensure finite‐time synchronization for stochastic complex networks with time delays. An effective controller is given to guarantee inner finite‐time synchronization, especially for a nondelayed dynamic system. This paper provides a simple controller. Finally, a numerical simulation is given to demonstrate the effectiveness of our results.