共查询到19条相似文献,搜索用时 80 毫秒
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分析了当前高等院校实验室管理中注重静态的帐目管理而缺乏动态的监控管理的实际,构建了一种基于现场总线技术的实验设备的动态监控系统。 相似文献
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Helko Meyer 《流程工业》2006,(10):62-64
现场总线和它的引进,一直是企业讨论和考虑的问题。本文将首次回答这一问题:如何才能在其他通讯协议的基础上采用现场总线技术?其中涉及到一个非常重要的工具:FF-CIT——现场总线基金会研发的组态与集成工具包。它使用户回避了必须掌握详细的现场总线系统各个细节及编码等繁杂的工作。使用这种经过测试和实际应用检验的FF现场总线工具,可以降低产品研发的费用、缩短产品投放市场的时间。[编者按] 相似文献
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通常意义上,人们将自动化领域分为工厂自动化(FA)和过程自动化(PA),在FA中现场总线已经大量应用,而在PA中的应用尚在起步阶段,相应的实际应用案例较少,因此在PA中从业的相关人员对现场总线的认识往往还停留在纸面上。本文致力于将PA中最常使用的基金会现场总线(FOUNDATION FIELDBUS)和PROFIBUS-PA如何进行实际的网络构建展现给大家,以此增加大家对现场总线的一些感性认识,文中将按照从现场到控制室的方向进行介绍。 相似文献
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冷库自动化控制技术的优劣直接关系到冷库的初投资、运行费用、管理费等一系列重要的经济指标。实践证明:以计算机为监控中枢,采用基于Modbus协议的冷库现场总线监控系统构建冷库的自动化控制系统,是降低冷库综合费用的有效办法之一。 相似文献
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Sabine Mhlenkamp 《流程工业》2007,(4):44-45
近来,人们经常谈论流程设备故障诊断的问题——其中的核心问题是现场总线仪器仪表或者上一级的资产管理系统的故障诊断问题。而对信息通讯的监控,即总线系统的自我监控却讨论的不多。其主要原因是一批新近研发成功的信息通讯监控工具,使现场总线系统的通讯监控工作变得非常简单了。[编者按] 相似文献
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基于现场总线技术的先进控制系统 总被引:2,自引:0,他引:2
现场总线技术的发展,引起传统控制系统结构的改变。一些自动化软件公司充分利用现场总线技术开放性的特点,以自主开发的控制系统软件为核心,推出基于现场总线技术的先进控制系统。本文描述了PLC控制系统向基于现场总线先进控制系统的演变过程,分析了系统结构组成及市场前景。 相似文献
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The performance of a wafer fabrication system is constrained by its bottlenecks, which are difficult to detect and improve due to the complexity within the system. To weaken the negative effects of bottlenecks, a work in process (WIP) strategy is proposed in this paper which focuses on offline target WIP level setting and online WIP control simultaneously. First, bottlenecks are detected and classified based on the constraint weights which are decided by the sensitivity of the system performance to the machine's fluctuant availability. Second, the target WIP level is allocated to the bottlenecks to avoid the process fluctuation caused by unpredictable events. Third, in real time scheduling, the upstream machine of the bottlenecks modifies its dispatching order to adjust the deviation of the WIP levels at the bottlenecks. Finally, a simulation platform is developed to validate the effectiveness of the proposed method. 相似文献
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In human immunodeficiency virus (HIV) infection, many factors may influence the counts of healthy cells, immune cells and viruses. Drug treatment design for the HIV dynamic system is a valuable subject to be studied. This study considers an HIV dynamic system model with some unknown parameters and unmeasurable CD8 + T cell count and proposes a switching control strategy to force all states of the system to achieve a healthy status. It is a switching form with two different drug therapies and is designed based on the Lyapunov function theory such that the states of the HIV system approach the health equilibrium asymptotically without the influence of unknown parameters and unmeasurable cell counts. The values of all states and drug concentrations are assured to be positive in the control process so that the control strategy can satisfy the actual treatment requirements. Finally, a numerical example is illustrated to show the effectiveness of the proposed control strategy.Inspec keywords: medical control systems, diseases, microorganisms, cellular biophysics, drugs, patient treatment, Lyapunov methods, switching systems (control)Other keywords: control process, switching control strategy, human immunodeficiency virus infection, healthy cells, immune cells, viruses, drug treatment design, HIV dynamic system model, unmeasurable CD8 + T cell count, switching form, drug therapies, Lyapunov function theory 相似文献
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W. Matthees 《International journal for numerical methods in engineering》1982,18(11):1601-1611
A closed solution for dynamic problems with the transform technique is possible for linear behaviour only. Therefore, a strategy for the solution involving nonlinear material behaviour has been developed. Herewith, an iterative equalization is made possible by the repeated transform of the differential equations given through the initial strain method. 相似文献
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针对目前工业现场大量8位普通微处理器尚未接入Internet的现状,本文详细介绍了基于51单片机的嵌入式Web服务器,并由此构建了基于二维精密工作平台的远程测控系统。经实践检验,此方案切实可行。 相似文献
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XIONG Liang cai HE Lin song SHI Tie lin YANG Shu zi Huazhong University of Science Technology Wuhan P.R.China 《国际设备工程与管理》2002,7(1)
1 IntroductionBeingtheessentialequipment,oncetherollingmillbreaksdownunexpectedlythelossescausedbyunscheduledshutdownandqualityabnormalitycanbeverysevere.Todealwiththisproblem ,moreandmorelargesteelworksintheworldresearchedontheCMAFDSofarollingmillandd… 相似文献
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