一类动态互联复杂系统的稳定性分析

通过引入动态图及动态邻接矩阵相关理论,对具有动态互联信息结构约束的复杂系统进行描述和建模,并引入Ｌｏｔｋａ Ｖｏｌｔｅｒｒａ方程作为该系统的动态互联信息结构模型．根据李雅普诺夫方法,对系统的动态互联模型进行了详细分析,研究了非负定限内联结平衡的设定及其渐近稳定条件,进而研究了整个系统的稳定条件．最后得到了该类动态互联复杂系统联结稳定及整个系统稳定的相关结论．

     

一类互联电力系统的鲁棒联结稳定性分析

研究一类互联电力系统在不确定结构扰动下的鲁棒联结稳定问题．基于系统中互联矩阵的不确定性给出了鲁棒联结稳定的定义,利用向量Lyapunov函数方法及范数、特征值的性质推导了此类系统鲁棒联结稳定的两个充分条件．对系统在不确定结构扰动下联结稳定的鲁棒程度进行分析,得到了不确定参数的鲁棒界．两区域互联电力系统的仿真实例说明了所推导条件的有效性．     

单调控制系统的简化定理与多重稳定性

多重稳定性是许多分子生物模型重要的动力学行为,它在分析细胞分裂和生长现象中起到关键性的作用.为了了解细胞内的复杂的调节网络的动力学行为,将其数学模型进行单调分解为若干个单调控制系统的互联.对具有惟一定义的稳定状态响应的单调控制系统,引入了具有保持局部稳定性质的简化系统,根据简化系统的平衡点与原来单调控制系统的平衡点之间存在的一一对应的映射关系,可推知单调控制系统的平衡点的位置及其稳定性.进而通过确定单调控制系统的平衡点的位置及平衡点的稳定性.来确定整个互联单调控制系统的平衡点的位置及平衡点的稳定性.由于简化系统降低了原来生物系统模型的雏数,这为分析复杂生物系统的稳定性提供了一种可行的途径.     

动态系统的一致同余安全

研究动态系统的安全问题．针对动态系统运行时间配置的可变特性，引入了动态系统的进程代数模型和复杂动态系统概念，定义了动态系统的一致安全性质和一致同余安全性质．基于观察同余等价，构造了一类一致同余安全模型．本文证明，动态系统的安全性质是一致安全性质，而对于复杂动态系统，其安全性质是一致同余安全性质．     

带有界扰动的一类大型互联非线性系统的鲁棒分散控制

研究带有界扰动的一类大型互联非线性系统的鲁棒分散控制问题, 该系统的第i个子系统的标称模型具有相对阶r_i及指数稳定的零动态, 且每个子系统的互联项满足匹配条件. 通过子系统状态的线性变换得到鲁棒分散状态反馈控制器, 当该控制律作用于系统时, 系统的状态能够收敛到原点的一个小邻域内, 并给出仿真算例说明该结论的可行性和有效性.     

一种多agent的并行认知模型及应用

agent认知模型是多agent系统研究的基础。该文抓住多agent系统的社会行为特性,构建了动态的多agent系统模型。它可以动态地调整系统agent的个数,增强系统的求解问题的能力,整个系统随着问题求解的增多更加稳定。并且在构建动态多agent系统的基础上给出了多agent系统并行认知模型及其相关概念,并把该模型应用于问题求解。     

一类切换模糊时滞组合系统的分散镇定

提出了切换模糊时滞组合系统模型,并研究了状态和互联项具有时滞情况下的分散镇定问题.当每个互联子系统中的每个切换子系统具有有限个备选的状态反馈控制器,且单一控制器均不能保证系统稳定的情况下,利用多Lyapunov函数方法给出了时滞相关的矩阵不等式条件和分散切换律设计方法,使系统在所提出的分散切换律和分散控制器下渐近稳定.仿真结果表明了所提出方法的有效性.     

基于误差反馈的组合式人工神经网络的发电生产过程辨识

本文主要研究人工神经网络在辨识实际工业系 统中的应用．由于辨识的对象是一个动态系统,所以着重对人工神经网络在辨识工业生产过 程的动态特性作了分析．本文以发电生产过程为背景,针对不同负荷下发电生产工况的特点 ,提出了用子神经网络分别辨识不同负荷下的发电生产过程．在考虑系统稳定的前提下,本 文提出引入误差反馈来训练人工神经网络辨识模型的方法．     

基于T-S模糊模型的复杂系统的灵敏度分析

针对输入具有互联的系统的灵敏度分析常常会产生不正确结果的问题，提出一种获取这种复杂系统灵敏度信息的方法．这种方法首先需要建立系统的基于自适应神经模糊推理系统的T-S模糊模型以及各个输入的T-S模糊模型;然后从这些模糊模型抽取出灵敏度信息．同时讨论了这种输入具有互联的系统的模糊建模方法,仿真实例验证了所提出的抽取灵敏度信患方法的正确性.     

递归复合型模糊神经网络结构研究

针对一类能够有效引入过程先验知识的复合型模糊神经网络，研究了其动态结构． 通过对复合型模糊神经网络的函数网络的第二层引入动态递归环节，使其具有动态映射能力 ，实现了对动态系统的良好响应．本文采用了动态非线性模型对其进行仿真研究，结果 表明，对于处理动态非线性系统，此动态复合模糊神经网络较之静态网络在收敛速度、预测 精度和网络规模等方面都有较大的改善．     

互联大系统动态输出反馈多重叠鲁棒分散关联镇定

针对一类具有网型拓扑结构的互联大系统,提出一种动态输出反馈多重叠鲁棒分散关联镇定方法.该方法将系统状态空间加以扩展,在扩展空间中将其分解为按循环逆序排列的一系列两两子系统对,并为每个子系统对分别设计使其关联稳定的鲁棒分散动态输出反馈控制器,将这些多重叠设计的控制器再收缩回原空间,实现控制律的协调.将该方法应用到一个四区域网型电力系统控制设计中,仿真结果验证了所提出方法的可行性和优越性.     

A new decentralised controller design method for a class of strongly interconnected systems

In this paper, two interconnected structures are first discussed, under which some closed-loop subsystems must be unstable to make the whole interconnected system stable, which can be viewed as a kind of strongly interconnected systems. Then, comparisons with small gain theorem are discussed and large gain interconnected characteristics are shown. A new approach for the design of decentralised controllers is presented by determining the Lyapunov function structure previously, which allows the existence of unstable subsystems. By fully utilising the orthogonal space information of input matrix, some new understandings are presented for the construction of Lyapunov matrix. This new method can deal with decentralised state feedback, static output feedback and dynamic output feedback controllers in a unified framework. Furthermore, in order to reduce the design conservativeness and deal with robustness, a new robust decentralised controller design method is given by combining with the parameter-dependent Lyapunov function method. Some basic rules are provided for the choice of initial variables in Lyapunov matrix or new introduced slack matrices. As byproducts, some linear matrix inequality based sufficient conditions are established for centralised static output feedback stabilisation. Effects of unstable subsystems in nonlinear Lur'e systems are further discussed. The corresponding decentralised controller design method is presented for absolute stability. The examples illustrate that the new method is significantly effective.     

Decentralized adaptive stabilization of interconnected nonlinear systems with unknown non-symmetric dead-zone inputs

The decentralized adaptive stabilization method is proposed for uncertain interconnected nonlinear systems with unknown non-symmetric dead-zone inputs. The class of systems considered in this paper consists of strict-feedback nonlinear subsystems with unknown non-symmetric dead-zone inputs which interact through their outputs. The unknown nonlinear interaction terms are assumed to be bounded by nonlinear functions with unknown parameters. For the simple controller design, the local controller for each subsystem is systematically derived based on the dynamic surface design technique, without constructing the dead-zone inverse and requiring the bound information of dead-zone parameters (slopes and break-points). All unknown parameters of interconnected nonlinear systems are compensated by the adaptive technique. From Lyapunov stability theorem, it is proved that all signals in the interconnected closed-loop system with decentralized adaptive controllers are semi-globally bounded. Simulation results for tripled inverted pendulums demonstrate the effectiveness of the proposed approach.     

String stability of interconnected systems

Introduces the notion of string stability of a countably infinite interconnection of a class of nonlinear systems. Intuitively, string stability implies uniform boundedness of all the states of the interconnected system for all time if the initial states of the interconnected system are uniformly bounded. It is well known that the input output gain of all the subsystems less than unity guarantees that the interconnected system is input-output stable. The authors derive sufficient (“weak coupling”) conditions which guarantee the asymptotic string stability of a class of interconnected systems. Under the same “weak coupling” conditions, string-stable interconnected systems remain string stable in the presence of small structural/singular perturbations. In the presence of parameter mismatch, these “weak coupling” conditions ensure that the states of all the subsystems are all uniformly bounded when a gradient-based parameter adaptation law is used and that the states of all the systems go to zero asymptotically     

Decentralized control of dynamically interconnected systems

Interconnected systems, where the subsystems are interconnected by some dynamic interaction system, are considered. It is shown that this type of system can be stabilized by decentralized dynamic output feedback, if the subsystems are stabilizable by (centralized) dynamic output feedback and the interaction system is stable. The relation to previous results is discussed.     

Stability of Large Space Structures Preserved Under Failures of Local Controllers

This note considers position and attitude control of large space structures composed of a number of subsystems (substructures) interconnected by flexible links. A decentralized control law of dynamic displacement feedback compatible with subsystems is applied under the assumption that sensors and actuators are collocated. It has been known that the overall closed-loop system is robustly stable against uncertainties in mass, damping, and stiffness, if rigid modes of each subsystem are controllable and observable. The objective of this note is to derive conditions for the overall system to be stable even when some local controllers fail. The conditions are expressed in terms of the stiffness (or damping) matrices and interconnection location matrices of the subsystems whose local controllers fail     

基于动态矩阵的隔振器滞回动力自动控制系统设计

现有基于PLC的隔振器滞回动力自动控制系统存在控制误差高的不足,为此设计了一种基于动态矩阵控制算法的自动控制系统。系统的硬件部分由动态控制中心、伺服电机、动力传感器、前置信号放大器、及数据计算单元等关键的模块构成,为提高系统的控制性能在伺服电机模块中内置了型号的单片机控制器,保证电磁控制信号的稳定输出;依据动态矩阵控制算法原理设计了自动化控制系统的主控程序,并给出了动态预测矩阵控制的基本流程,利用动态滚动预测的模式来降低控制时域内的误差,并保证滞回动力值的稳定输出;分析数据表明,提出的自动化控制系统在功能性方面可以满足批量测试及远程控制的要求,在3个稳态值条件下的系统误差都明显低于传统隔振器控制系统,最高的误差输出在0.05之间。     

一类非线性互联系统的间接自适应模糊滑模跟踪控制

基于模糊逻辑逼近原理,针对非线性动态未知互联系统,设计一种新的模糊分散控制 器.讨论了互联项满足或不满足一般性约束条件的两种情形,用不同方法来补偿其对大系统的影 响.同时利用模式转换函数来实现间接自适应控制与模糊滑模控制之间的转换,使系统的状态在 有界闭集内变化,并依据Lyapunov方法证明了闭环系统稳定,跟踪误差收敛到零的一个小邻域 内.仿真结果证明所设计的模糊控制器的有效性.     

基于闭相关页面集实现网站自适应

自适应网站能够根据用户需要快速灵活地改变自身，动态适应不断变化的用户需求和应用环境.本文基于图的频繁闭项集从站点一定时期内的日志中挖掘出闭相关页面集，据此提供在线动态推荐为用户导航，改善了传统的合作推荐存在的稀疏性和扩展性问题，在不增大网站服务器负荷的情况下提高对所有用户的信息服务质量.最后，分析了两种测量推荐系统性能的方法并对系统进行评价.     

Leader–follower tracking control with guaranteed consensus performance for interconnected systems with linear dynamic uncertain coupling

This paper considers the leader–follower tracking control problem for linear interconnected systems with undirected topology and linear dynamic coupling. Interactions between the systems are treated as linear dynamic uncertainty and are described in terms of integral quadratic constraints (IQCs). A consensus-type tracking control protocol is proposed for each system based on its state relative to its neighbours. In addition, a selected set of subsystems is used to control their relative states with respect to the leader. Two methods are proposed for the design of this control protocol. One method uses a coordinate transformation to recast the protocol design problem as a decentralised robust control problem for an auxiliary interconnected large-scale system. Another method is direct; it does not employ coordinate transformation, rather it also allows for more general linear uncertain interactions. Using these methods, sufficient conditions are obtained which guarantee that the system tracks the leader. These conditions guarantee a suboptimal bound on the system consensus and tracking performance. The proposed methods are compared using a simulation example, and their effectiveness is discussed. Also, algorithms are proposed for computing suboptimal controllers.