Consensus Control in Linear Multi‐Agent Systems with Current and Sampled Partial Relative States

This paper studies consensus in linear multi‐agent systems with current and sampled partial relative states. A distributed linear consensus protocol is designed, where both current and sampled relative states are utilized. A necessary and sufficient condition for consensus in this setting is established. The notion of the consensus region is then introduced and analyzed for third‐order systems, provided that each agent can only know its relative positions and velocities. It is shown that the consensus regions are stable to control gains and sampling period. Additionally, how to choose the control gains and the sampling period is given for consensus in third‐order systems. Finally, an example is given to verify and illustrate the analysis.     

Observer‐based consensus of second‐order multi‐agent system with fixed and stochastically switching topology via sampled data

This paper addresses the distributed observer‐based consensus problem of second‐order multi‐agent systems via sampled data. Firstly, for the case of fixed topology, a velocity‐independent distributed control law is proposed by designing a distributed observer to estimate the unavailable velocity, then a sufficient and necessary condition of consensus on design parameters and sampling period is obtained by using the matrix analysis method. Secondly, for the case of stochastically switching topology, a sufficient and necessary condition of mean square consensus is also proposed and proven, and an algorithm is provided to design the parameters in the consensus protocol. Two simulation examples are given to illustrate the effectiveness of the proposed consensus algorithms. Copyright © 2012 John Wiley & Sons, Ltd.     

双馈风场进线对220 kV母线采样值差动保护的影响

由于采样值差动保护具有计算速度快、易考虑CT饱和等优点而被普遍应用于当前的母线保护装置中。然而暂态特性不同于传统火电机组的双馈风电机组大量接入电力系统,这会给现有的继电保护带来严重的挑战。以双馈风电场远距离接入220 kV电压等级变电站母线为例,在RTDS仿真平台上研究双馈风场进线对母线采样值差动保护的影响。结果表明,在母线区内故障时风场侧支路提供的短路电流存在弱馈、高谐波及频率偏移等特点。与此同时,计及CT饱和、双馈机组本身的无功优化控制策略等因素影响,使得该短路电流的复杂性更加突显,进而造成传统母线釆样值差动保护动作有延迟。为此,提出了一种自适应变数据窗的釆样值差动保护判据,并通过RTDS仿真平台验证了该方法行之有效。     

步行姿态驱动的虚拟漫游控制及校准方法初探

基于步行姿态的虚拟环境漫游控制模块研究,虽增强了操作者对自身步行方向与速度的直接感知,但都因为模块内受限的姿态,面临着如何将其中侦测到的采集速度,校准为虚拟环境中应有的平地速度的难题。该研究基于自主研发的此类被动式模块提出“等心率步行速度换算方法”。通过对四组共93名志愿者分别在模块内与平地上进行不同速度步行时的心率进行记录,分绘出心率与两种速度的关系方程,再按照同心率同体感的假设,建立起各组的采集速度与平地速度换算方程（换算比0.0186至0.0211）。即该方法可针对某类目标人群科学地解决上述校准问题。     

非接触式金属液面检测技术研究

介绍非接触式高温金属熔液液面图象处理检测技术,使用ＣＣＤ图象传感技术与计算机图象处理技术相结合,将金属液面转换成视频图象,再利用计算机进行图象处理、采样、转换等,以图形及数字和模拟方式输出液位高度值．此技术已成功地应用在云南冶炼厂铸连轧金属液面自控系统中,取得良好的使用效果．     

IEC 61850标准下采样值传输的应用

采样值传输是变电站自动化系统过程层与间隔层串行通信的重要组成部分,电子式电流/电压互感器的出现使得采样值数字化传输成为可能.该文在对变电站通信网络和系统的最新国际标准--IEC61850标准特点分析的基础上,围绕变电站过程层采样值传输问题,从IEC61850信息模型出发,研究了模拟量采样值传输模型、抽象模型通信服务和采样值报文格式,给出了变电站系统中模拟量采样值建模的一般步骤和传输过程中,为满足数字化变电站分散布置的信息采集和传输要求提供了解决方案.     

Spectral necessary and sufficient conditions for sampling-period-independent stabilisation of periodic and aperiodic sampled-data systems using a class of generalised sampled-data hold functions

Sampling-period-independent (SPI) stabilisation of both periodic and aperiodic sampled-data systems using a class of generalised sampled-data hold functions is addressed. It is proved that for this specific class of hold functions, a continuous-time linear system with rank-minimal input matrix and with non-defective eigenvalues on the imaginary axis is SPI-stabilisable if and only if the spectrum of the system is contained in the closed left-half plane. A systematic procedure for constructing suitable state-feedback controllers is also provided. Several examples are finally discussed for illustration.     

On the stability problem for distributed parameter energy systems†

In this paper asymptotic stability of the non-trivial or operating equilibrium state of a distributed parameter energy system is considered. Sufficient conditions are obtained by the method of comparison functions. This enables one to obtain bounds on the maximum value of the state variables. The criteria derived depend on the eigenvalues of the linearized system as well as on a bound for the feedback control law.     

采样值电流差动保护原理的研究

对采样值电流差动保护的原理与常规电流差动保护进行了比较研究,同时讨论了采样值电流差动保护中存在的动作边界变化区的特殊问题,定量给出了不同采样速率时动作边界变化区的范围,并简单说明了采样值电流差动保护动作出口的适宜速度。     

具有随机时延的网络化控制系统基于等价空间的故障诊断

随着控制系统技术的飞速发展，把网络环节引入到传统的控制系统实现迅速准确的远 距离闭环控制是人们日益关注的课题．而网络中由信息的碰撞、重发而产生的网络延迟对控 制系统本身带来的负面影响却不容忽视．本文针对网络化控制系统(Networked Control S ystem，简称NCS)的随机延时，提出了延时估计和在线获得延时数据的两种方法，建立控制 对象的数学模型．利用z变换来处理延时，由等价关系产生残差，通过参数设计解耦干扰向 量，从而对网络化系统的控制故障进行了诊断，并提供了仿真结果．