Self-triggered sampling control for networked control systems with delays and packets dropout

In this paper, a self-triggered sampling (STS) scheme is proposed for a networked control system with delays and packets dropout. Sampling periods are given based on a probability of successful transmission for packets by signal-to-interference-and-noise ratio measured via quality-of-service. The networked control system is described as a switched delta operator system by the STS scheme. Sufficient conditions of stability for the network control system with delays and packets dropout are given with average dwell time in terms of linear matrix inequalities. A numerical example is given to illustrate the effectiveness and potential for the developed techniques.     

STABILITY ANALYSIS OF NETWORKED SYSTEMS WITH PACKET DROPOUT AND TRANSMISSION DELAYS: DISCRETE‐TIME CASE

This paper analyzes the stability of networked control systems (NCSs) with data packet dropout and transmission delays induced by communication channels. Discrete‐time NCSs with data packet dropout and transmission delays are modeled as linear systems with time‐varying delays. Sufficient conditions for the stability of the NCSs are established in terms of linear matrix inequalities (LMIs) by using the Lyapunov function method. The case of NCSs with multiple‐packet transmission is also studied. A numerical example is presented to illustrate our proposed approach.     

Quantitative analysis and synthesis for networked control systems with non‐uniformly distributed packet dropouts and interval time‐varying sampling periods

This paper is concerned with quantitative analysis and synthesis for a networked control system under simultaneous consideration of non‐uniformly distributed packet dropouts, interval time‐varying sampling periods and network‐induced delays. A new packet dropout separation method is proposed to separate packet dropouts from the lump sum of network‐induced delays and packet dropouts. An interval time‐varying sampling period approach, which is more general than a switched sampling period approach, is presented to model the variation of the sampling period. Then a packet dropout decomposition‐based Lyapunov functional is constructed to drive some stability criteria. Based on these stability criteria, a state feedback controller is designed to asymptotically stabilize the networked system in the sense of mean‐square. Numerical examples are given to illustrate the effectiveness of the obtained results. Copyright © 2013 John Wiley & Sons, Ltd.     

具有双通道数据包丢失的Delta算子系统故障检测

研究同时存在双通道数据包丢失和时变时延的Delta算子网络控制系统（NCSs）故障检测问题.假定数据包丢失发生在控制器到执行器、传感器至控制器的数据传输过程中，并且利用两个相互独立的伯努利随机变量描述是否发生丢包.将上述的NCSs建模为网络切换系统，提出任意切换律下故障检测滤波器的设计方法.利用线性矩阵不等式（LMIs）方法、Lyapunov-Krasovskii泛函和平均驻留时间等得出所考虑的网络切换系统具备指数均方稳定性的充分条件.证明了所用的网络切换系统满足H_∞性能，并推导出了滤波器参数的显式表达.数值仿真结果验证了所提方法的有效性.     

Robust exponential stabilization for network-based switched control systems

It has become a common practice to employ networks in control systems for connecting controllers and sensors/actuators on controlled plants and processes. A network-based switched control system, as a special case of networked control systems, is studied. Such a system is represented with network-induced delays and packet dropout as a switched delay system. Sufficient conditions for robust exponential stability are derived for a class of switching signals with average dwell time. A stabilization design for continuous-time, linear switched plant with nonlinear perturbation under a given communication network via a hybrid state feedback controller is proposed. A hybrid controller design is network-dependent and given in terms of linear matrix inequalities.     

On exponential stability of linear networked control systems

This paper addresses exponential stability of linear networked control systems. More specifically, the paper considers a continuous‐time linear plant in feedback with a linear sampled‐data controller with an unknown time varying sampling rate, the possibility of data packet dropout, and an uncertain time varying delay. The main contribution of this paper is the derivation of new sufficient stability conditions for linear networked control systems taking into account all of these factors. The stability conditions are based on a modified Lyapunov–Krasovskii functional. The stability results are also applied to the case where limited information on the delay bounds is available. The case of linear sampled‐data systems is studied as a corollary of the networked control case. Furthermore, the paper also formulates the problem of finding a lower bound on the maximum network‐induced delay that preserves exponential stability as a convex optimization program in terms of linear matrix inequalities. This problem can be solved efficiently from both practical and theoretical points of view. Finally, as a comparison, we show that the stability conditions proposed in this paper compare favorably with the ones available in the open literature for different benchmark problems. Copyright © 2012 John Wiley & Sons, Ltd.     

Stability of linear discrete switched systems with delays based on average dwell time method

This paper deals with the problem of exponential stability for a class of linear discrete switched systems with constant delays.The switched systems consist of stable and unstable subsystems.Based on the average dwell time method, some switching signals will be found to guarantee exponential stability of these systems.The explicit state decay estimation is also given in the form of the solutions of linear matrix inequalities(LMIs).An example relating to networked control systems(NCSs) illustrates the effect...     

时变采样周期网络控制系统的鲁棒容错控制器设计

研究具有时变采样周期网络控制系统的执行器失效的完整性问题．假设系统任意两个连续采样间隔具有上界,利用输入时延法,将时变采样周期网络控制系统等价转化为连续时变时延网络控制系统．在此基础上,基于时延条件,应用Ｌｙａｐｕｎｏｖ稳定性理论和线性矩阵不等式（ＬＭＩｓ）方法证明了鲁棒容错控制律的存在条件,设计了鲁棒容错控制器,并给出了系统完整性条件下的最大允许时延的估计方法．仿真结果验证了所提方法的可行性和有效性．     

Delay‐dependent dissipativity analysis and synthesis of switched delay systems

In this paper, we study the problem of dissipative analysis for a class of switched systems with time‐varying delays. Sufficient conditions for dissipativity are developed for a class of switching signals with average dwell time. These conditions express delay‐dependent exponential stability and are provided in terms of linear matrix inequalities (LMIs). It is shown that the derived results encompass some available results on ??_∞ approach and arbitrary switching case. Numerical examples are given to illustrate the developed results. Copyright © 2010 John Wiley & Sons, Ltd.     

Quantized stabilization of networked control systems with actuator saturation

In this paper, we investigate the problems of stabilization of networked control systems with quantization and actuator saturation via delta operator approach. The definition of the domain of attraction for delta operator systems is introduced to analyze the stochastic stability of the closed‐loop networked control systems. The quantizer is a uniform one with arbitrary quantization regions, and the packet dropout process is modeled as a Bernoulli process. On the basis of the zoom strategy and Lyapunov theory in delta domain, sufficient conditions are given for the closed‐loop delta operator systems to be mean square stable, and the feedback controllers are designed to ensure the stability of networked control systems. A single link direct joint driven manipulator model is presented to show the effectiveness of the main results. Copyright © 2016 John Wiley & Sons, Ltd.     

H∞ Control Synthesis for Lurie Networked Control Systems with Multiple Delays Based on the Non‐Uniform Characteristic

This paper investigates the H _∞ control synthesis problem for Lurie networked control systems (NCSs) with multiple time‐varying delays. With the consideration of both network‐induced delays and data packet dropout, Lurie NCSs discussed in this work can effectively be transformed into Lurie control systems with multiple time‐varying delays. In addition, with the non‐uniform distribution characteristics of network delays, based on the delay probability distribution, the stable controller design, and H _∞ synthesis, approaches are derived in the form of linear matrix inequalities (LMIs). Finally, a set of numerical examples are studied, and the results demonstrate the applicability and effectiveness of the suggested approaches.     

Finite-time boundedness and stabilisation of networked control systems with bounded packet dropout

In this paper, the finite-time boundedness and stabilisation problems of a class of networked control systems (NCSs) with bounded packet dropout are investigated. The main results provided in the paper are sufficient conditions for finite-time boundedness and stability via state feedback. An iterative approach is proposed to model NCSs with bounded packet dropout as jump linear systems (JLSs). Based on Lyapunov stability theory and JLSs theory, the sufficient conditions for finite-time boundedness and stabilisation of the underlying systems are derived via linear matrix inequalities (LMIs) formulation. Moreover, both sensor-to-controller and controller-to-actuator packet dropouts are considered simultaneously. Lastly, an illustrative example is given to demonstrate the effectiveness of the proposed results.     

MIMO网络控制系统的建模与分析

针对网络只存在于传感器节点与控制器节点之间的多输入多输出(MIMO)网络控制系统,研究了系统建模和稳定性问题.设传感器节点和控制器节点均为时间驱动,且它们的采样存在着固定的时间差,网络诱导时延的上界大于一个采样周期,建立了此类网络控制系统的模型.基于Lyapunov函数和线性矩阵不等式(LMIs)方法,给出了闭环系统渐近稳定的充分条件.仿真表明本文的方法是有效的.     

Stability and Stabilization of Networked Control Systems Under Limited Communication Capacity and Variable Sampling

This paper investigates the problem of quantized feedback control for networked control systems (NCSs) with time‐varying delays and time‐varying sampling intervals, wherein the physical plant is a continuous‐time, and the control input is a discrete‐time signal. By using an input delay approach and a sector bound method, the network induced delays, the signal quantization and sampling intervals are presented in one framework in the case of the state and the control input by quantization in a logarithmic form. We exploit a novel Lyapunov functional with discontinuity, taking full advantage of the NCS characteristic information including the bounds of delays, the bounds of sampling intervals and quantization parameters. In addition, it has been shown that the Lyapunov functional is decreased at the jump instants. Furthermore, we use the Leibniz‐Newton formula and free‐weighting matrix method to obtain the stability analysis and stabilization conditions which are dependent on the NCS characteristic information. The proposed stability analysis and stabilizing controller design conditions can be presented in term of linear matrix inequalities, which have less conservativeness and less computational complexity. Four examples demonstrate the effectiveness of the proposed methods.     

具有不确定丢包率和时变采样周期的Delta算子系统故障检测

研究一类由Delta算子描述具有不确定丢包率的时变采样网络控制系统故障检测问题.数据包丢失发生在传感器至控制器、控制器到执行器的数据传输过程中,丢包模型采用两个相互独立的伯努利随机变量表示,假设传感器至控制器通道中的丢包率是不确定的,其均值由常数和不确定值两部分组成.时变采样周期利用有限长切换序列表示可降低保守性.采用Delta域的Lyapunov函数方法,提出所考虑的增广系统渐近稳定且具有${\textstyle H_{\infty     

数据包丢失网络控制系统的保成本控制

针对同时具有不确定短时延及数据包丢失的网络控制系统,引入丢包补偿器补偿丢包对系统的影响,当发生数据包丢失时,控制器采用丢包补偿器产生的预估状态代替系统的真实状态计算控制量。同时考虑不确定短时延的影响,将网络控制系统建模为一类具有参数不确定的离散切换系统．利用线性矩阵不等式(linear matrix inequality,简称LMI)方法给出了系统的保成本控制器和丢包补偿器的协同设计方法,仿真结果表明所提出的方法是有效的。     

网络传输迟延与丢包的补偿及系统稳定性分析

针对网络传输在控制系统中引发的问题，提出在控制器节点采用针对迟延和丢包的补偿估计器．以提高控制系统的性能。当迟延小于一个采样周期且数据包传输率已定时，将包含该补偿估计器的网络控制系统（CEDPNCS），描述为具有两个事件的异步动态系统，并推导出保证系统稳定的时变双线性矩阵不等式．仿真结果表明．所提出的方法能有效提高控制系统的性能．     

Robust H∞ filtering for a class of Markovian jump systems with time‐varying delays based on delta operator approach

In this paper, the robust H_∞ filtering problem for a class of discrete Markovian jump systems with time‐varying delays and linear fractional uncertainties is investigated based on delta operator approach. Based on Lyapunov‐Krasovskii functional in delta domain, new delay‐dependent sufficient conditions for the solvability of this problem are presented in terms of linear matrix inequalities (LMIs). When these LMIs are feasible, an explicit expression of a desired jump H_∞ filter is given. The proposed method can unify some previous related continuous and discrete systems into the delta operator systems framework. Numerical examples are given to illustrate the effectiveness of the developed techniques. © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

网络控制系统随机稳定性研究

研究了具有随机网络诱导时延及数据包丢失的网络控制系统随机稳定性问题. 本文用一个具有两个状态的马尔可夫链来描述数据通过网络传输时随机数据包丢失过程, 利用马尔可夫跳变线性系统理论, 将网络控制系统建模为一个具有两种运行模式的马尔可夫跳变线性系统, 给出了在状态反馈控制下网络控制系统随机稳定的线性矩阵不等式形式的充分条件, 最后用一个仿真示例验证了该方法的有效性.     

Adaptive stabilisation of networked control systems tolerant to unknown actuator failures

In this article, adaptive state feedback stabilising controllers for networked adaptive control systems with unknown actuator failures are developed. The problems of networked control systems (NCSs) such as transmission delays and data-packets dropout, induced by the insertion of data networks in the feedback adaptive control loops are also considered. The novelty of this article consists in the combination of different aspects in NCSs: state tracking control of systems with unknown parameters, unknown actuator failures, network-induced delays and data-packets dropout. Normalised adaptive laws are designed for updating the controller parameters. Sufficient conditions for Lyapunov stability are derived in the case of uncertainty due to actuator failures, delays and data-packets dropout. Simulation results are given to illustrate the effectiveness of our design approach.