时延丢包网络控制系统的分析与控制

针对网络控制系统中同时存在时延和丢包问题,基于零阶保持器的工作机制,将同时受时延和丢包影响的网络控制系统建模为输入带有时延的控制系统,根据李雅普诺夫稳定性理论和时滞系统理论得出控制系统的时滞相关稳定性条件,进一步基于锥补线性化的方法给出控制器的设计方法,有效解决了网络控制系统中同时存在时延和丢包的控制问题。仿真算例表明所提方法的有效性。     

具有快变时延和丢包的网络控制系统镇定

对一类网络控制系统,研究了变时延和数据丢包对闭环系统稳定性的影响.基于Lyapunov-Krasovskii方法,给出了闭环系统的稳定条件,该条件不依赖于时延变化率的上界.通过求解一个适当的线性矩阵不等式(LMI)得到控制增益矩阵,求解时不需要对矩阵的结构进行限制,也不必使用重复迭代.最后,给出了一个数值例子以说明方法的有效性.     

具有长时延和丢包的网络控制系统稳定性分析

针对同时出现长网络诱导时延和丢包的网络控制系统,研究了带不确定性的网络控制系统的稳定性问题。基于一定的数据包丢失率,系统被建模成带结构事件率约束的异步动态系统。利用李亚普诺夫方法和线性矩阵不等式相关知识,结合异步动态系统的稳定性理论,推出了使不确定网络控制系统指数稳定的充分条件,并给出了保证系统指数稳定的数据传输成功率满足范围;最后利用MATLAB仿真的数值例子验证了此方法的有效性和可行性。     

存在数据丢包的网络控制系统的控制

将存在数据丢包的网络控制系统描述为跳跃系统。基于一个李雅普诺夫泛函,只需满足4个线性矩阵不等式,便可通过带状态观测的状态反馈控制使闭环系统达到稳定。由于得到的条件不是严格的线性矩阵不等式条件,将不具有严格线性矩阵不等式条件的非凸可行解问题转化为具有严格线性不等式的非线性最小化问题,得到了求解状态反馈控制器增益和状态观测器增益的算法。数值仿真结果验证了该算法的有效性。在所设计的状态反馈控制器的校正作用下,闭环系统的响应是渐近稳定的。     

时延网络控制系统的模型预测控制

针对有输入约束的不确定时延网络控制系统,提出鲁棒模型预测控制方法;其中,将不确定时延建模为范数有界的输入矩阵的不确定性．给出了鲁棒性能指标的上界和系统渐近稳定的充分条件,通过在线求解LMI凸优化问题得到状态反馈控制律．仿真例子验证了该方法的有效性．     

时延网络控制系统的稳定性

针对网络控制系统中存在的不确定时延 ,首先讨论了系统的建模问题 .系统中传感器采用时间驱动 ,执行器与控制器采用事件驱动 ,传感器的数据采用单包传输 .假设传输时延小于采样周期 ,网络控制系统可以建模为一类具有不确定性的线性离散时延系统 .利用Lyapunov方法 ,给出了闭环系统渐近稳定的充分条件 ,基于相应的线性矩阵不等式可行解 ,可以求解状态反馈控制律 .最后 ,用仿真例子验证了该方法的有效性     

一类丢包时延网络控制系统的鲁棒H∞滤波

用随机马尔可夫跳变系统描述一类具有丢包时延的网络控制系统．为这类网络控制系统设计马尔可夫跳变滤波器,保证了滤波误差系统均方意义下随机渐近稳定,且噪声信号对估计误差的影响低于指定H∞ 性能水平,滤波器参数可通过求解线性矩阵不等式得到．最后通过仿真实例验证了所得结论的正确性和滤波器设计方法的有效性．     

具有随机丢包的网络控制系统的镇定

研究具有随机丢包的网络控制系统(NCS)的镇定问题.同时考虑传感器节点到控制器节点(S/C)和控制器节点到执行器节点(C/A)的随机丢包,并分别对这两种丢包现象建模.基于Lyapunov稳定性理论,得到闭环系统全局均方渐近稳定的充分条件.进一步利用线性矩阵不等式(LMI)方法,得到状态反馈控制律的增益矩阵.数值仿真算例验证了所得结果的有效性.     

不确定时延网络控制系统的优化控制实现

针对不确定时延使网络控制系统性能下降的问题,基于Lyapunov函数和线性矩阵不等式,得出不确定性时延线性离散系统的闭环系统是渐近稳定且满足H性能指标的充分条件,将其应用在基于Internet的扳手劲竞赛控制系统的控制器设计中,实践证明所提算法能够提高网络控制系统在不确定时延影响下的动态性能。     

不确定时延网络控制系统的保性能控制

在工程实际网络控制系统中,不仅要求系统能够保持稳定,还要系统具有一定的性能指标,采用状态反馈控制是一种非常有效的控制方式。针对一类线性不确定时延网络控制系统,研究了在有记忆状态反馈控制器下的保性能控制问题。利用Lyapunov函数和线性矩阵不等式的方法,给出了网络控制系统保性能控制律存在的条件和相应的状态反馈控制器的设计方法。最后,通过Matlab数值仿真算例验证了该方法的有效性和正确性。     

时滞系统方法的网络控制系统的研究

针对普遍存在的采样器和零阶保持器异步这一现象,研究了该类网络控制系统的状态反馈控制问题。首先,以事件驱动的零阶保持器的更新时刻为时间标识,并考虑到网络的诱导时延和数据丢包,建立网络控制系统的采样闭环模型,并转化为状态中连缀着两个时滞变量的时滞系统。然后,利用相应的时滞系统方法,对闭环网络控制系统进行了稳定性分析和控制器综合。最后,通过仿真实例验证了所得结果的正确性。     

Robust stabilization for a class of nonlinear networked control systems

The problem of robust stabilization for a class of uncertain networked control systems （NCSs） with nonlinearities satisfying a given sector condition is investigated in this paper. By introducing a new model of NCSs with parameter uncertainty, network-induced delay, nonlinearity and data packet dropout in the transmission, a strict linear matrix inequality （LMI） criterion is proposed for robust stabilization of the uncertain nonlinear NCSs based on the Lyapunov stability theory. The maximum allowable transfer interval （MATI） can be derived by solving the feasibility problem of the corresponding LMI. Some numerical examples are provided to demonstrate the applicability of the proposed algorithm.     

Stability analysis of networked control systems with time-varying sampling periods

In this paper, we present an interval model of networked control systems with time-varying sampling periods and time-varying network-induced delays and discuss the problem of stability of networked control systems using Lyapunov stability theory. A sufficient stability condition is obtained by solving a set of linear matrix inequalities. In the end, the illustrative example demonstrates the correctness and effectiveness of the proposed approach.     

Stochastic stability of networked control systems with network-induced delay and data dropout

This paper deals with the stochastic stability of networked control systems with the presence of network- induced delay and transmitted data dropout. Based on the Lyapunov approach, sufficient conditions for the mean-square stability of the networked control system are derived subject that the sequence of transmission interval is driven by an identically independently distributed sequence and by a finite state Markov chain, respectively. Stabilization controllers are constructed in terms of linear matrix inequalities correspondingly. An example is provided to illustrate our results.     

Output tracking control for networked control systems with time delay and packet dropout

This article studies the problems of H _∞ output tracking performance analysis and controller design for networked control systems (NCSs) with time delay and packet dropout. By using linear matrix inequality (LMI)-based method, H _∞ output tracking performance analysis and controller design are presented for NCSs with constant sampling period. For NCSs with time-varying sampling period, a multi-objective optimisation methodology in terms of LMIs is used to deal with H _∞ output tracking performance analysis and controller design. The designed controllers can guarantee asymptotic tracking of prescribed reference outputs while rejecting disturbances. The simulation results illustrate the effectiveness of the proposed H _∞ output tracking controller design.     

Predictive observer‐based control for networked control systems with network‐induced delay and packet dropout

This paper addresses the stability analysis and synthesis problems for a class of networked control systems (NCSs) under effects of both network‐induced delay and packet dropout. The motivation comes from the increasing NCS applications where the full state vector is not available. To handle the concerned problems, two predictive observer‐based controllers are constructed. The first one is a memoryless controller with the predictive observer collocated with the plant. The second one, with the predictive observer colocated with the controller, uses the last effective plant information as well as the knowledge of the plant dynamics. The stability conditions of NCSs are derived via both network‐condition‐dependent Lyapunov function and common quadric Lyapunov function. The corresponding controller design problems are also solved based upon the obtained stability conditions. Simulation and experimental results are given to demonstrate the effectiveness of the proposed approaches. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

A new delay system approach to network-based control

This paper presents a new delay system approach to network-based control. This approach is based on a new time-delay model proposed recently, which contains multiple successive delay components in the state. Firstly, new results on stability and H_∞ performance are proposed for systems with two successive delay components, by exploiting a new Lyapunov-Krasovskii functional and by making use of novel techniques for time-delay systems. An illustrative example is provided to show the advantage of these results. The second part of this paper utilizes the new model to investigate the problem of network-based control, which has emerged as a topic of significant interest in the control community. A sampled-data networked control system with simultaneous consideration of network induced delays, data packet dropouts and measurement quantization is modeled as a nonlinear time-delay system with two successive delay components in the state and, the problem of network-based H_∞ control is solved accordingly. Illustrative examples are provided to show the advantage and applicability of the developed results for network-based controller design.     

时变时滞NCS控制器的改进设计

建立时滞差分不等式,得到网络化控制系统(NCS)的指数稳定判据,基于该判据设计NCS状态反馈控制器。该设计以线性矩阵不等式(LMI)形式给出,不包含任何自由矩阵,通过Matlab中的LMI工具箱进行求解。数值仿真结果表明,该设计具有计算量小、求解方便、保守性弱的特点。