具有时变输入时滞的不确定T-S模糊系统的鲁棒稳定性

本文主要针对不确定的输入变时滞 T-S 模糊系统设计模糊控制器使系统鲁棒稳定. 首先基于 Lyapunov-Krasovskii 泛函方法, 通过引入更多的松弛变量矩阵, 以 LMI 形式给出使此模糊系统稳定的充分条件. 在设计模糊控制器时并不要求满足时变输入时滞的导数小于1的限制条件. 最后给出数值仿真例证本文提出的结果的有效性且保守性更小.     

A Switched System Approach to Robust Stabilization of Networked Control Systems with Multiple Packet Transmission

This paper considers robust stabilization of networked control systems (NCSs) with the problem of multiple packet transmission. Two parts of uncertainties are considered in this paper: norm‐bounded parameter uncertainties in the plant, and norm‐bounded parameter uncertainties in the controller. For sensor nodes and actuator nodes communicating through a limited communication channel, we are particularly interested in the case that only one packet containing part of the state information can be transmitted through a toking‐bus every time. Stability of the NCSs with multiple packet transmitted in a periodic manner is closely related to that of periodically switched systems. For NCSs with and without uncertainties in the plant and the controller, stabilizing state feedback controllers are constructed in terms of linear matrix inequalities (LMIs). Numerical examples are given to illustrate the feasibility and effectiveness of the proposed approach.     

一种改进的具有非理想网络状况的网络控制系统分析与综合方法

提出一种改进的具有非理想网络状况, 如时变网络时延和丢包等的网络控制系统分析与综合方法. 在引入具有最新信号选择功能的逻辑零阶保持器和已有的网络系统模型基础上, 采用Lyapunov-Krasovskii泛函方法, 通过引入自由矩阵消除交叉项和利用函数的凸性进行等价变换, 得到保守性较小的效果. 实例表明上述方法的有效性.     

不确定时滞模糊系统的鲁棒H∞网络控制

A robust H_∞networked control method for Takagi-Sugeno (T-S) fuzzy systems with uncertainty and time delay is presented.A state feedback controller is designed via the networked control system (NCS) theory.Sufficient condition for robust stability with H_∞performance is obtained.Network-induced delay in network transmission and packet dropout are analyzed. Simulation result shows the validity of this control scheme.     

一类不确定时延网络控制系统的稳定性分析

针对网络控制系统中时延不确定因素,将时延的不确定性转换为系统状态方程系数矩阵的不确定性,基于LMI和Lyapunov理论,研究了一类具有时延的网络控制系统的稳定性问题,并运用Lyapunov方法和线性矩阵不等式对不确定时延系统进行了稳定性分析。并以Riccati不等式和线性矩阵不等式的形式给出了系统稳定的充分条件,使得在不确定时延情况下,系统达到理想稳定性。最后,通过Matlab工具箱对数值结果进行仿真,在时延相关情况下,求得系统达到闭环稳定时最大允许的时延,表明了设计方法的有效性。     

变采样周期网络化系统鲁棒容错控制

针对网络控制系统中存在的时变采样周期与时延,通过矩阵Jordan 变换与分解, 将采样周期和时延的不确定性转变为系统结构参数的不确定性,建立了离散时间凸多面体不 确定系统模型。在此基础上,首先设计观测器,保证系统状态和故障估计收敛于实际值。接 着,根据估计的故障,设计了主动动态输出反馈鲁棒容错控制器,给出了执行器发生故障时, 系统能保持渐近稳定的充分条件。将控制器设计问题转化为以线性矩阵不等式形式为约束条 件的凸优化问题,进而得出了最优H∞鲁棒容错控制器参数的具体表达式。数值仿真验证了提 出的设计方法的有效性。     

基于模糊卡尔曼滤波器的网络控制系统状态估计

针对基于T S模糊模型的网络控制系统提出了一种卡尔曼滤波器的设计方法．先运用卡尔曼滤波理论给每个子系统设计出子滤波器，然后通过这些子滤波器的模糊融合得出全局滤波器．本文证明此全局滤波器可实现无偏状态估计，并给出了其稳定的条件．最后用仿真实例验证了所提出的卡尔曼滤波器的有效性．     

网络控制系统中基于时延辨识的模糊控制器研究

针对网络控制问题，建立包含变网络时延及网络传输丢包等的统一模型．提出基于允许误差阈值及最大时延等多重准则的网络调度算法．在被控对象模型已知的情况下，本文采用模糊控制器作为Smith控制的内模控制部分，同时将Smith预估环节与被控对象放在一处，减少了冗余信息的传输，补偿了网络时延．仿真结果说明该调度算法及控制方案对于模型精确已知的一类网络控制对象能取得较好的控制效果．     

一类带有时延的非线性网络控制系统可靠模糊控制

研究了带有状态时延及执行器故障的非线性网络控制系统的可靠模糊控制问题. 利用输入时延方法, 将带有网络诱导时延和数据包丢失的非线性网络控制系统等价的转化为具有时变时延的Takagi-Sugeno(T-S)模糊系统. 时延对象的状态信息, 采用时滞分解方法, 得以充分的考虑. 并利用锥补线性化迭代算法, 将非凸的稳定性条件转化成可行的线性矩阵不等式(LMI)的形式. 文中将更紧的界处理方法(相互凸组合技术)与不相关增广矩阵项引入到Lyapunov函数的处理当中, 获得保守性更小的稳定性条件. 数值算例验证了该方法的有效性.     

基于网络控制的球杆系统模糊控制器设计

针对网络化控制系统中存在的网络延时的不确定性,提出了如何根据系统的控制性能要求处理网络传输过程中网络延时的时变特性.通过对网络环境的分析,把网络延时进行分段序列化,使时变的网络延时转换成一个固定延时序列.在球杆系统本地化控制中加入固定延时,获取不同延时情况下球杆系统的最佳控制参数.在网络控制中,通过捕获的网络延时查找最...     

广义线性系统的分散控制

从混合型输出反馈控制的角度讨论了广义线性系统的分散控制问题，给出了一个广义性系统在混合型分散输出反馈下存在脉冲固定模的充分条件，提出卫通过实现分散正常化消除脉冲固定模的有效算法。     

基于动态调度的网络控制系统设计方法

针对网络控制系统中存在多回路共享网络资源的问题,本文提出一种基于反馈和预测机理的动态调度策略,根据当前的网络状态在线调整控制系统的采样周期,以适应当前网络中信息流的变化,达到改善网络运行性能的目的．采用动态调度策略的网络控制系统为不确定变采样周期系统,经过等效变换,将系统等效为一类具有参数不确定性的离散系统．基于建立的模型,给出系统的鲁棒控制器参数化设计方法,并通过仿真实例验证了所提方法的有效性．     

Static Output Feedback Control for Interval Type‐2 T‐S Fuzzy Systems Based on Fuzzy Lyapunov Functions

This study aims to design an interval type‐2 (IT2) fuzzy static output feedback controller to stabilize the IT2 Takagi‐Sugeno (T‐S) fuzzy system. Conservative results may be obtained when a common quadratic Lyapunov function is utilized to investigate the stability of T‐S fuzzy systems. A fuzzy Lyapunov function is employed in this study to analyze the stability of the IT2 fuzzy closed‐loop system formed by the IT2 T‐S fuzzy model and the IT2 fuzzy static output feedback controller. Stability conditions in the form of linear matrix inequalities are derived. Several slack matrices are introduced to further reduce the conservativeness of stability analysis. The membership‐function shape‐dependent analysis approach is also employed to relax the stability results. The numerical examples illustrate the effectiveness of the proposed conditions.     

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.     

网络控制系统的网络安全研究

基于网络控制系统(networkedcontrolsystem,NCS)的基本概念,分析了NCS网络安全体系结构和动态需求,讨论了确保NCS网络安全的各种安全机制,提出了自律分散NCS安全体系策略,指出了如何设计具有自律可控性和自律可协调性的NCS安全体系的思想方法,并给出了相应的模型结构。     

Takagi-Sugeno Fuzzy Regulator Design for Nonlinear and Unstable Systems Using Negative Absolute Eigenvalue Approach

This paper introduces a Takagi-Sugeno(T-S)fuzzy regulator design using the negative absolute eigenvalue(NAE)approach for a class of nonlinear and unstable systems.The open-loop system is initially embodied by the traditional T-S fuzzy model and then,all closed-loop subsystems are combined using the proposed Max-Min operator in place of traditional weighted average operator from the controller side to lessen the coupling virtually and simplify the proposed regulator design.For each virtually decoupled closed-loop subsystem,the composite regulators(i.e.,primary and secondary regulators)are designed by the NAE approach based on the enhanced eigenvalue analysis.The Lyapunov function is utilized to guarantee the asymptotic stability of the overall T-S fuzzy control system.The most popular and widely used nonlinear and unstable systems like the electromagnetic levitation system(EMLS)and the inverted cart pendulum(ICP)are simulated for the wide range of the initial conditions and the enormous variation in the disturbance.The transient and steady-state performance of the considered systems using the proposed design are analyzed in terms of the decay rate,settling time and integral errors as IAE,ISE,ITAE,and ITSE to validate the effectiveness of the proposed approach compared to the most popular and traditional parallel distributed compensation(PDC)approach.     

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．     

Controller Design for Networked Control System with Uncertain Parameters

This paper deals with the problem of controller design for NCSs （networked control systems） with uncertain parameters and network induced time-delays. In the case of long time delay constraint and data package loss, the closed-loop model of a class of NCSs is presented for controlled objects with uncertain parameters. Based on Lyapunov stability theory combined with LMIs （linear matrix inequalities） techniques, the design method of state feedback controller for NCSs with asymptotic stability is given in the form of LMIs. Numerical example and simulation suggest that the results are effective and are an improvement over previous ones.     

基于LMI的网络化控制系统的时滞相关研究

针对在网络化控制系统中不可避免的网络诱导时延会降低系统性能以及影响系统的稳定性问题,提出了一种基于线性矩阵不等式的时滞相关优化方法。构建了在网络诱导时延情形下网络化控制系统的数学模型,继而分析设计了基于LMI的时滞相关控制器。仿真实验中采用了Matlab的LMI工具箱,并结合了一定的迭代策略,结果表明,该方法具有一定的优越性。     

非线性大系统的分散自适应模糊控制*

本文针对非线性大系统，利用模糊系统的逼近能力，提出了一种分散自适应模糊控制器设计的系统方法。控制结构中采用分散模糊系统去自适应补偿过程不确定性，同时用模糊控制器的输出代替常规变结构控制律中的符号函数。利用李亚普诺夫理论，证明了控制算法是全局稳定的，跟踪误差可收敛到零的一个领域内。