远程网络化测控系统研究与实现

网络化远程测控是目前一个研究方向，而网络的体系结构决定着测控性能和技术实现。文章设计了远程测控系统的体系结构．用远程测控器、内含嵌入式WEB服务器的本地测控器、局部测控器和RS485现场总线实现了远程网络化测控系统．给出了具体的软，硬件结构和基于Internet的实现技术。     

基于网络的远程测试系统技术研究

随着自动测试技术与网络技术的紧密结合,基于网络的远程测试系统迅速发展.测试技术网络化不仅可以降低测试系统成本,有利于实现远距离测控和测试资源共享,而且有利于实现设备的远距离诊断和维护.此网络测试系统主要是将现有的自动测试技术和仪器应用于远程测试系统中,根据仪器接入远程测试系统的方式,介绍了其一般硬件构成,并且分析了其软件结构、主要工作模式及相关软件开发方法,最后介绍了基于网络的远程测试系统的发展.     

基于工业以太网的远程测控系统

对多种测控系统的信息通信、数据采集、网络结构、控制模式进行了研究,在分析了各种总线网络的优缺点之后,提出了一种新型的基于以太网的远程测控系统。本测控系统利用以太网为通信媒介,采用分布式控制结构,实现了对远程对象的实时监控。基于以太网的测控技术具有良好的发展前景,是未来网络测控技术的发展方向。     

嵌入式Web传感器中BP网络的研究及实现

本文基于当前社会对网络化、分布化、远程化、非线性和智能化的要求,以嵌入式Web传感器为研究对象,分析了基于以太网的远程测控系统。侧重研究了嵌入式系统中引进人工神经网络的具体实现方法。成功地将BP网络应用在ARM平台,实现了对复杂非线性问题的准确处理,该方法为神经网络走进嵌入式Web传感器领域提供了一条廉价有效的途径。     

基于无线数传与CDMA的远程测控网络

文中提出了微功率无线数传网络与CDMA网络相结合,组成远程测控网络。该网络以无线数传网络连接测控终端,通过无线中继单元将测控数据传输到CDMA网络;以CDMA网络作为测控数据远程传输媒介,通过Internet与数据中心相连。该网络兼具无线数传与CDMA网络的优点,通信稳定可靠,安装及运行成本低廉,已经在油井远程测控系统中被应用。     

浅谈基于单片机的嵌入式系统的网络应用

基于单片机的嵌入式系统网络化是其发展的一个重要方向,本文通过例举基于单片机的嵌入式网络服务器的应用及基于单片机的嵌入式网络测控系统的应用,阐述了基于客户端／服务器模型的单片机嵌入式系统如何实现应用。     

具有时延和丢包的不确定性NCS的稳定性

研究了同时具有网络时延和数据丢包的不确定网络化控制系统的稳定性.将数据丢失看成一种特殊的时延,利用动态反馈控制器设计提高系统的动态性能,得到了总时滞(包括传感器与控制器之间的时滞,控制器与执行器之间的时滞)的表达式,建立了不确定网络化控制系统模型.通过构造李亚普诺夫函数,采用线性矩阵不等式技巧,给出了系统稳定的判定定理.仿真结果表明了该方法的有效性.     

基于远程网络的虚拟仪器的开发初探

介绍了远程网络虚拟技术的特点和构成,说明了远程网络虚拟仪器是网络技术与虚拟仪器技术的结合。改变了传统的测控模式,可以实现测量、分析、测控等在空间上的分离。     

基于ARM＋ZigBee的通用网络测控系统硬件设计

根据当前网络化测控需求,采用了ARM920T核的微处理器S3C2440,ZigBee无线SoC芯片CC2430F128相结合的硬件设计方案,设计了一种基于ARM和ZigBee的通用网络化测控系统硬件平台,详细阐明了系统各模块的硬件设计。实际应用表明,系统硬件平台网络性能好、通用性强且成本较低。     

基于不确定非线性智能电网感知网络控制系统方法研究

针对传统的不确定时滞的鲁棒控制系统不能满足现代电力系统发展的需求,提出一种基于不确定非线性智能电网感知云网络化控制识别方法。使用传统的数据值和基于电力网络到网络系统模型作为电力感知网络到网络模型的电力云网络,控制数据优化使用电源感知网络,而不是利用控制节点的预测值,突破了鲁棒控制的不确定时滞系统的控制效果。运用感知模型中的正向云算法修正加权系数,仿真实验证明,该识别方法能够很好地优化传统的不确定时滞鲁棒控制电力系统,具有良好的适应性和鲁棒控制性,进一步提高了智能电网传感云网络控制的各项性能指标。     

模型预测控制在网络闭环控制中的应用研究

在基于Internet的远程控制系统中,通过Internet进行信息传输的时间延时的不确定性对实时闭环控制系统的设计带来较大的困难.研究了网络传输延时对网络闭环控制系统的影响,提出了通过基于神经网络的预测控制方法解决存在网络随机延时的控制系统闭环控制的可行性.仿真结果表明该方法能够反映并预测该测量数据所代表的网络路径之间的时延特性,并能在基于Internet的闭环控制系统的设计中有效地替代实际网络进行研究;而所用的方法具有快速、准确的特点,能用于在线学习网络模型并对网络的时延值进行预测,为基于Internet的远程闭环控制提供了新的思路.     

基于EMD与LS-SVM的网络控制系统时延预测方法

为了提高基于Internet的网络控制系统中随机时延的预测精度,提出了基于经验模式分解(empirical mode decomposition,EMD)与最小二乘支持向量机(Least Squared Support Vector Machines,LS-SVM)的一步时延预测方法.首先利用EMD将时延序列分解成若干个本征模式函数分量,分解后的分量去除了原始时延序列的长相关性,同时突出时延序列不同的局部特征.然后根据各个分量的变化规律,选择不同的LS-SVM模型分别进行预测.最后将各分量的预测值叠加得到最终的预测值.仿真结果表明本文方法具有较高的预测精度.     

Networked Predictive Control Systems Based on the Hammerstein Model

In this paper, a novel predictive control-based approach is proposed for a networked control system with random delays containing an input nonlinear process based on a Hammerstein model. The method uses a time-delay two-step generalized predictive control scheme, which consists of two parts: one is to deal with the input nonlinearity of the Hammerstein model and the other is to compensate for the network-induced delay in the networked control system. A theoretical result using the Popov criterion is presented for the closed-loop stability of the system in the case of a constant delay. Simulation examples illustrating the validity of the approach are also presented.     

基于相空间重构与最小二乘支持向量机的时延预测

针对网络控制系统的时延预测问题,提出一种基于相空间重构与最小二乘支持向量机的时延预测方法.首先利用0-1测试法确定时延序列具有混沌特性,引入相空间重构技术提高预测精度.对实际采集的时延序列进行Hurst指数分析,选择最小二乘支持向量机作为预测模型.然后利用C-C方法确定时延序列相空间重构参数,通过递归图确定时延序列的局部可预测性,利用遗传算法对最小二乘支持向量机的参数进行离线优化.最后通过优化后的最小二乘支持向量机并结合相空间重构对时延序列进行在线预测.与其它预测方法进行了仿真对比,结果表明本文方法具有更高的预测精度与更小的预测误差,同时并未降低预测算法的实时性.     

Design the Remote Control System With the Time-Delay Estimator and the Adaptive Smith Predictor

In real applications, a remote control system is generally an integration of different networks consisting of a commercial network for message transmission and an industrial network to control the remote hardware through a communication gateway. Since the induced time-delay in network control system (NCS) may cause system instability, this paper proposes a remote NCS structure by implementing the adaptive Smith predictor with an online time-delay estimator. As the delay in a commercial network Ethernet is significantly time-varying depending on the number of end-users, the delay is estimated in this paper by processing the online measurement of the round-trip time (RTT) between the application layers of the server and the client. The adaptive Smith predictor control scheme is developed by directly applying the estimated time-delay. To prove the feasibility of the proposed remote control system, the developed design has been applied to an AC 400 W servo motor tested from a 15 km distance. The experimental results indicate that the significantly improved stability and motion accuracy can be reliably achieved by applying the proposed approach.      

地空通信和卫星通信组网实现电台的远程控制

地空话音通信在民航、军航以及许多军事指挥系统中有广泛应用.介绍了卫星通信系统与地空通信系统组网方式,实现20部地空电台的远程集中控制,完成区域指挥中心(SOC)对空指挥功能,并对其技术实现进行了探讨.     

基于网络的武器系统动态测量时滞误差的分析与修正

以基于网络的武器系统动态测量为研究背景,对网络化动态测量系统进行建模和误差分析.提出了动态测量时滞误差(TDE)的概念,讨论了TDE对动态测量误差处理结果的影响.根据武器系统动态测量的具体应用,着重介绍了一种基于时戳的在线时滞估计方法,解决了武器系统动态测量过程中网络时滞误差的问题.     

Gain adaptation of networked DC motor controllers based on QoS variations

Connecting a complex control system with various sensors, actuators, and controllers as a networked control system by a shared data network can effectively reduce complicated wiring connections. This system is also easy to install and maintain. The trend is to use networked control systems for time-sensitive applications, such as remote DC motor actuation control. The performance of a networked control system can be improved if the network can guarantee quality-of-service (QoS). Due to time-varying network traffic demands and disturbances, QoS requirements provided by a network may change. In this case, a network has to reallocate its resources and may not be able to provide QoS requirements to a networked control application as needed. Therefore, the application may have to gracefully degrade its performance and perform the task as best as possible with the provided network QoS. This paper proposes a novel approach for networked DC motor control systems using controller gain adaptation to compensate for the changes in QoS requirements. Numerical and experimental simulations, and prototyping, are presented to demonstrate the feasibility of the proposed adaptation scheme to handle network QoS variation in a control loop. The effective results show the promising future of the use of gain adaptation in networked control applications.     

A design method of the wide-area damping controller of the power system considering the communication time-delay based on an iterative identification

There must be a non-negligible communication time-delay in the transmission process of wide area information through the power system. Communication time-delay will reduce the system stability or even cause system instability, and also there exists an identification error problem in the model identification. Therefore, the identification error will make model parameters not accurate enough, and it cannot ensure the control effect of the power system time-delay damping controller. Aiming at the problem of communication time-delay and identification error in the power system, firstly, a closed-loop time-delay model of the power system is described in this paper. Secondly, a design method of iterative identification damping controller of the power system considering the time-delay (constant delay and time-varying delay) is proposed. In addition, the whole step of the proposed method and a mathematical calculation method of the exact time-delay controller model are given. Finally, the four-machine two-area system model is taken as an example in this paper. Simulation results show that the response of both angle and active power of motor can stabilize within 8 seconds. The designed controller in this paper can effectively suppress low frequency oscillation and ensure the stability of power system.