一类Lipschitz 非线性切换系统基于观测器的 H∞ 输出跟踪控制

针对一类Lipschitz非线性切换系统,研究基于观测器的H∞输出跟踪控制问题.借助微分中值定理,将Lipschitz非线性切换系统转化为线性参数切换系统.当状态变量不可测或不易测时,利用多Lyapunov函数方法,同时设计观测器、基于观测器的跟踪控制器和滞后切换信号,使得系统满足H∞输出跟踪性能.最后通过仿真例子表明了设计方法的有效性.     

切换LPV系统的抗攻击无扰切换控制

本文针对遭受切换冲击和网络数据注入攻击影响的切换线性变参(LPV)系统,给出保护网络信息安全传输的抗攻击机制,提出一种无扰切换控制方法.首先,设计一种新颖的基于编码/解码器的抗攻击机制,可抵御恶意注入攻击信号对系统反馈通信的干扰.基于此,建立切换LPV系统的抗攻击动态输出反馈闭环控制模型.考虑到模式之间的无扰过渡问题,给出与动态输出反馈控制设计互为补充的,满足无扰切换设计需求和H∞性能指标的控制增益可行条件.在本文提出的控制律下,进一步获取了能保证切换LPV系统指数稳定性的充分条件.最后,通过数值仿真验证所提出抗攻击无扰切换控制方法的有效性.     

具有一步随机通讯时延的网络化切换系统H∞滤波

针对数据包在网络中传输的一步随机时延情形,研究任意切换律作用下的离散切换系统的H∞滤波问题.时延数据包包含系统的测量输出信号和切换信号,其时延由一个满足Bernoulli分布的随机变量来描述.选用切换Lyapunov函数,设计全阶和降阶的切换滤波器使得滤波误差系统在均方意义下指数稳定且具有扰动衰减度γ.滤波器的参数通过...     

基于LM Is 的不确定线性切换系统H ∞鲁棒控制

基于线性矩阵不等式(LMI)和H∞控制理论,研究一类不确定线性切换系统在任意切换策略下的H∞鲁棒控制问题.系统矩阵和输入矩阵都含有时变不确定性.首先利用矩阵Schur补引理构造LMI,得到该系统在H∞意义下渐近稳定的充分条件;然后给出了在状态反馈下和输出反馈下的H∞鲁棒稳定性的充分条件;最后用数值例子验证了文中结果的正确性.     

一类时滞切换奇异系统的指数H∞滤波器研究

研究了一类时滞切换奇异系统的指数H∞滤波问题.为了提高控制系统的稳定性,解决系统的指数H∞滤波的难点问题,提出利用平均驻留时间方法,首先给出了使得滤波误差系统在切换信号下具有指数可容许性并且具有相应的H∞性能指标的条件,然后以一组线性矩阵不等式的形式给出了期望滤波器存在的充分条件,并给出了相应的滤波器参数求解.所设计的指数H∞滤波器不但保证系统参数不确定时闭环系统指数稳定,而且满足所期望的H∞性能指标.最后用数值仿真实例来说明设计方法的有效性和可行性.     

切换广义系统的H∞输出反馈控制

针对一类切换广义系统,提出了一种更加简单易解的H∞输出反馈控制方法.基于投影引理和Finsler's引理结合线性矩阵不等式技术,给出保证闭环系统在输出反馈控制下是容许的并具有期望的H∞性能水平的严格线性矩阵不等式条件.所提出的充分条件不要求对系统模型进行坐标变换,也不需要对Lyapunov矩阵和其逆矩阵进行分解.给出的结果可经例子进行验证并可以推广到单一的广义系统和正常的切换系统.     

具有随机协议网络化系统的H_∞滤波

本文研究了一类具有随机介质访问协议网络化系统的H∞滤波问题.将传感器和滤波器的通信过程描述为一个马尔可夫链,进而将滤波误差系统建模成一个马尔可夫跳变系统.然后,运用李雅普诺夫方法和线性矩阵不等式技术,给出了滤波误差系统随机稳定且具有给定H∞性能的一个充分条件,并基于该条件给出了H∞滤波器的设计方法.最后的数值算例验证了本文方法的有效性.     

Research of cooperative transmission technology based on H ∞ filter energy prediction

研究了一种适用于分布式移动无线传感器网络数据传输基于能量预测的协作通信技术.针对无线传感器网络,协作数据传输技术难以有效解决无线网络动态拓扑结构、带宽和能量受限等问题,建立了一种基于H∞滤波器相邻节点剩余能量预测的分布式中继选择机制,并在此基础上建立数据协作传输技术.该技术充分利用无线信道的广播特性,首先根据H∞滤波器预测节点剩余能量,然后根据剩余能量值选择最大者作为协作节点,最后根据无线信道质量在放大重传和解码重传机制之间进行自适应调整.数学分析表明,H∞滤波器可以准确地预测节点的剩余能量,同时该协作传输技术能够显著提高无线传感器网络的资源利用率和系统吞吐率,有效延长网络寿命.     

具有状态时滞的离散时间切换系统的H∞ 滤波器设计: 依赖状态的切换方法

讨论一类时滞离散时间切换系统的H∞滤波器的设计问题.首先,当所有子系统都稳定时,基于切换Lyapunov函数和Finsler引理,得到了滤波误差系统渐近稳定且具有指定的H∞性能指标的充分条件,即使切换系统的每个子系统均不稳定,通过利用多Lyapunov函数方法和依赖状态的切换技术仍能保证切换系统稳定;然后,设计了H∞滤波器,并得到滤波误差系统满足指定的H∞性能指标的充分条件;最后,通过数值算例验证了所提出方法的有效性.     

具有控制约束的网络控制系统的鲁棒H_∞控制

针对具有控制约束的网络控制系统(Networked Control Systems,NCS)的特点,建立了具有外部扰动的网络控制系统模型,对其H∞性能加以分析和研究,并验证所取得的理论成果.假设具有控制约束的网络控制系统的H∞控制器与执行器均为事件驱动,传感器为时间驱动,且网络诱导时延小于传感器的采样周期,然后将此类网络控制系统的广义被控对象建模为一类线性离散系统,运用Lyapunov函数和线性矩阵不等式(LMI),导出闭环系统渐近稳定且满足给定H∞性能指标的充分条件,并给出了控制器的具体求法.得到了系统的H∞控制器存在条件及具体方法,通过设计该控制器,使具有外部扰动的网络控制系统的性能有很大的改善,通过Matlab仿真证明该控制器行之有效.     

Target tracking based on the extended H-infinity filter in wireless sensor networks

In this paper, we propose a new target tracking approach for wireless sensor networks (WSNs) by using the extended H-infinity filter. First, the extended H-infinity filter for nonlinear discrete-time systems is deduced through the Krein space analysis scheme. Then, the proposed extended H-infinity filtering algorithm is applied to target tracking in wireless sensor networks. Finally, experiments are conducted through a small wireless sensor network test-bed. Both experimental and simulation results illustrate that the extended H-infinity filtering algorithm is more accurate to track a moving target in wireless sensor networks than using the extended Kalman filter in the case of having no knowledge of the statistics of the environment and the target to be tracked.     

Multirate parallel distributed compensation of a cluster in wireless sensor and actor networks

The stabilisation problem for one of the clusters with bounded multiple random time delays and packet dropouts in wireless sensor and actor networks is investigated in this paper. A new multirate switching model is constructed to describe the feature of this single input multiple output linear system. According to the difficulty of controller design under multi-constraints in multirate switching model, this model can be converted to a Takagi–Sugeno fuzzy model. By designing a multirate parallel distributed compensation, a sufficient condition is established to ensure this closed-loop fuzzy control system to be globally exponentially stable. The solution of the multirate parallel distributed compensation gains can be obtained by solving an auxiliary convex optimisation problem. Finally, two numerical examples are given to show, compared with solving switching controller, multirate parallel distributed compensation can be obtained easily. Furthermore, it has stronger robust stability than arbitrary switching controller and single-rate parallel distributed compensation under the same conditions.     

Adaptive tracking H-infinity control for switched nonlinear systems with unknown control gain sign

This paper addresses the adaptive tracking control scheme for switched nonlinear systems with unknown control gain sign. The approach relaxes the hypothesis that the upper bound of function control gain is known constant and the bounds of external disturbance and approximation errors of neural networks are known. RBF neural networks (NNs) are used to approximate unknown functions and an H-infinity controller is introduced to enhance robustness. The adaptive updating laws and the admissible switching signals have been derived from switched multiple Lyapunov function method. It’s proved that the resulting closed loop system is asymptotically Lyapunov stable such that the output tracking error performance and H-infinity disturbance attenuation level are well obtained. Finally, a simulation example of Forced Duffing systems is given to illustrate the effectiveness of the proposed control scheme and improve significantly the transient performance.     

基于LMI的鲁棒容错控制及其在卫星姿态控制中的应用

研究了一种线性不确定系统的鲁棒容错控制问题.针对执行机构和敏感器故障,运用线性矩阵不等式(LMI)方法,提出一种对执行机构和传感器失效具有完整性,且满足给定控制指标的输出反馈H∞鲁棒容错控制设计方法.将该方法应用于卫星姿态控制系统的容错控制并进行了数学仿真,仿真结果验证了方法的有效性.     

一类时滞广义非线性系统H_∞可靠跟踪控制

讨论一类Lipschitz时滞非线性广义系统的H∞可靠跟踪控制问题.分别给出了执行器失效和传感器失效两种模型下可靠控制器存在的充分条件,使得闭环系统正则无脉冲并且指数稳定,同时系统输出跟踪预先给定的可测参考模型的输出,且满足H∞性能指标,并利用线性矩阵不等式技巧给出了可靠控制器的设计方法.最后给出了一个数值例子,说明了本文所给出方法的有效性.     

An interference-aware multichannel media access control protocol for wireless sensor networks

Scalable Parallel Systems (SPS) have offered a challenging model of computing and poses fascinating optimizations in sensor networks. With the development of sensor hardware technology, a certain sensor node is equipped with a radio transceiver that can be tuned to work on multiple channels. In this paper, we develop a novel interference-aware multichannel media access control (IMMAC) protocol for wireless sensor networks, which takes advantage of multichannel availability. Firstly, each node is assigned with a quiescent channel to reduce hidden terminal beforehand, and then it makes channel adjustment according to dynamic traffic. Secondly, a scalable multichannel media access control protocol is designed to make a tradeoff between channel switching overhead and fairness, and it effectively supports for node unicast and broadcast based on the receiver-directed channel switching. We have implemented simulation to evaluate the performance of IMMAC by comparing with other relevant protocols. The results show that our protocol exhibits more prominent ability, which utilizes multichannel to make parallel transmission and reduce hidden terminal problems effectively in resource-constrained wireless sensor networks.     

H2/H∞保性能控制理论在静止无功发生器控制中的应用

利用H₂/H_∞保性能控制理论和直接反馈线性化, 给出了单机无穷大系统中, 具有参数摄动的静止无功发生器(STATCOM)的非线性控制模型. 使用MATLAB软件得出H₂/H_∞保性能控制律, 表示为线性矩阵不等式(LMI).在扰动及参数摄动的条件下进行了仿真. 结果表明这种控制方法同时具有鲁棒性和最优性能, 降低了单纯H_∞控制方法的保守性, 提高了电力系统的稳定性, 并满足电压精度的要求.     

Observer-based robust H-infinity control for uncertain switched systems

The problem of observer-based robust H-infinity control is addressed for a class of linear discrete-time switched systems with time-varying norm-bounded uncertainties by using switched Lyapunov function method. None of the individual subsystems is assumed to be robustly H-infinity solvable. A novel switched Lypunov function matrix with diagonal-block form is devised to overcome the difficulties in designing switching laws. For robust H-infinity stability analysis, two linear-matrix-inequality-based sufficient conditions are derived by only using the smallest region function strategy if some parameters are preselected. Then, the robust H-infinity control synthesis is studied using a switching state feedback and an observer-based switching dynamical output feedback. All the switching laws are simultaneously constructively designed. Finally, a simulation example is given to illustrate the validity of the results.     

一类变时滞饱和不确定系统鲁棒H∞滤波器设计

研究一类不确定时变时滞饱和系统的H∞滤波器设计问题.该类系统状态方程中含有时变时滞和有界不确定项,输出方程中含有饱和项,系统的噪声信号功率有界但统计特性未知.本文给出一种线性滤波器结构,提出一种新的设计方法.该方法主要应用Lyapunov-Krasovskii稳定性理论和线性矩阵不等式,来分析和设计滤波器;它能使得时变时滞项,饱和项以及不确定项在设计中得到有效处理,且所设计的滤波器能满足H∞性能指标,滤波器参数通过求解一种线性矩阵不等式来确定.例子的分析与仿真验证了本文方法的有效性.     

新型无线传感器网络节点供电方案

工业现场对振动信号等快变量进行采集时,需要对无线传感器网络节点进行在线供电.通过分析开关噪声对无线传感器网络节点通信质量的影响,并结合传感器网络的工作特点,给出无线传感器网络供电方案的设计要求.针对开关噪声的宽频谱特点,提出适用于无线传感器网络的供电方案,实验表明:该供电方案可有效消除电源噪声.