930 resultados para computer control


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研究了具有模糊截止期的多控制任务的实时调度问题,提出了奉献度的概念和最大奉献优先(LDF)的调度策略.为了减小因任务间频繁切换造成的系统开销,提出了基于抢占阈值的最大奉献优先(TLDF)调度策略.最后,通过仿真比较了LDF和TLDF两种调度策略,实现了具有模糊截止期的控制任务调度,在减少并均衡控制性能损失的同时提高系统计算资源的使用率.

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高频系统是HIRFL系统中一个很重要的组成部分。其工作的稳定性和可靠性直接影响到束流的大小和品质,通过远程计算对其控制的目的不仅使人们远离现场恶劣的工作环境,而且在于提高整个系统的稳定性和可行性。高频计算机控制系统(RFC)的控制对象就是这个高频系统,它包括两个高频机和三个稳定系统:频率稳定系统、相位稳定系统、幅度稳定系统。考虑到整个系统长时间的工作状况和对稳定性和可靠性的严格要求,系统在硬件接口上选择了具有标准接口和强的扩展能力的CAMAC系统。CAMAC机箱的串行连接通过接口板2926和计算机联系在一起。在CAMAC串行总线上共有4个机箱分别负责高频机、相位、幅度和频率系统。这套系统的软件工作在Windows98操作系统平台下。有三个部分组成软件部分:一是漂亮友好交互性强的界面,这部分是通过VB和VC混合编程得来。二是功能稳定、可靠性强的接口,这部分是在VC中建立DLL来完成最终驱动。还有一部分是数据库,这个数据库是由Access生成,用于存储程序中的参数和高频系统的运行参数。这三个部分在界面程序中有机结合在一起共同完成对整套系统的控制作用。目前这套系统已经完成,运行在中控室的控制平台上,经过测试工作效果还很不错。本论文主要具体阐述了这套系统的组成,以及在程序设计时的思路、过程还有一些问题的解决办法等。

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本文基于中国科学院的代物理研究所电子辐照室的谐振变压器型电子加速器计算机控制系统的研制工作。首先介绍了研制此种加速器的国际、国内的历史背景和前景,接着介绍了加速器的结构和工作原理,描述了加速器的计算机控制系统,着重介绍了加速器的束流强度稳定系统和能量稳定系统。在束流强度稳定系统中,首先介绍了束流稳定系统的工作原理、实现的方法和对灯丝加热电源的要求;通过对灯丝电源的控制达到对束流强度调节和稳定的目的。而灯丝电源处在IMV左右的高压端,为此设计了光路传输系统,把高压端与低压端隔离开,同时又能传输控制信号。用一台可编程序控制器(PLC)作为主要控制硬件完成控制任务,同时编写了PLC控制软件。对于能量稳定系统,介绍了其工作原理、外部硬件组成(包括另一台PLC站)。针对能量稳定系统的特殊要求,在软件方面设计两种工作模式:变频器稳定模式和加速器调试和维修使用。以上两个控制站都有完备的报菟显示功能。使用组态王5.0开发了上位机(工控机)的动态显示画面,它能完成计算机控制命令的发布、参数显示和随机修改控制参数等功能。实验表明以上工作都达到设计要求,效果良好。

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结合具体的工程项目介绍如何应用计算机完成对换热站的集中监控与管理,实现提高热效率和共热品质,改进企业管理等目的。

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本文简要介绍了美国普度大学CIM参考模型的具体内容、系统特征、系统经济效益、系统发展趋势以及存在的一些问题。

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本文阐述了离散时间点过程理论,时变马尔科夫链及鞅差分序列在城市交通车队状态观测器中的应用。并在此基础上,改进了[5]中的估计算法。用本文提出的非线性最小方差估计算法,对提供的交通状态进行估计,所得结果比[5]中算法精度有明显提高。在大连市某交通干线计算机控制系统中初步应用,取得了令人满意的结果。

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本文介绍了一个连续-离散复合仿真程序。该程序的连续部分基本取自美国的 CSS 程序。经作者扩充后成为复合仿真程序。扩充的模块包括采样系统仿真模块、两点边值问题求解以及参量最优化等。作者提出的单纯形搜索法改进策略可以显著加快参量最优化过程的收敛速度。

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这台显示器是根据某电力系统计算机控制的要求而设计的.本文简要介绍了设计特点及其在电力系统中实际应用的情况.本文介绍的监控显示器适用于工业过程控制.作者根据现场应用的经验,提出了研制工业监控显示器的一些想法.

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介绍了一个基于AGV的变速箱装配生产线的计算机控制系统的结构、设计思想、功能特点及应用。

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Complete supervised training algorithms for B-spline neural networks and fuzzy rule-based systems are discussed. By interducing the relationship between B-spline neural networks and certain types of fuzzy models, training algorithms developed initially for neural networks can be adapted by fuzzy systems.

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Flow injection analysis (FIA) was applied to the determination of both chloride ion and mercury in water. Conventional FIA was employed for the chloride study. Investigations of the Fe3 +/Hg(SCN)2/CI-,450 nm spectrophotometric system for chloride determination led to the discovery of an absorbance in the 250-260 nm region when Hg(SCN)2 and CI- are combined in solution, in the absence of iron(III). Employing an in-house FIA system, absorbance observed at 254 nm exhibited a linear relation from essentially 0 - 2000 Jlg ml- 1 injected chloride. This linear range spanning three orders of magnitude is superior to the Fe3+/Hg(SCN)2/CI- system currently employed by laboratories worldwide. The detection limit obtainable with the proposed method was determin~d to be 0.16 Jlg ml- 1 and the relative standard deviation was determined to be 3.5 % over the concentration range of 0-200 Jig ml- 1. Other halogen ions were found to interfere with chloride determination at 254 nm whereas cations did not interfere. This system was successfully applied to the determination of chloride ion in laboratory water. Sequential injection (SI)-FIA was employed for mercury determination in water with the PSA Galahad mercury amalgamation, and Merlin mercury fluorescence detection systems. Initial mercury in air determinations involved injections of mercury saturated air directly into the Galahad whereas mercury in water determinations involved solution delivery via peristaltic pump to a gas/liquid separator, after reduction by stannous chloride. A series of changes were made to the internal hardware and valving systems of the Galahad mercury preconcentrator. Sequential injection solution delivery replaced the continuous peristaltic pump system and computer control was implemented to control and integrate all aspects of solution delivery, sample preconcentration and signal processing. Detection limits currently obtainable with this system are 0.1 ng ml-1 HgO.

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An auto-switch device has been designed, constructed, and tested for multisensor corrosion measurements. The auto-switch is able to connect/disconnect the selected wire beam electrode and/or electrode pairs under computer control. A computer controlled analog switch-array consisting of 100 inputs has been used as an essential part of the switch bank. The switch-bank is an essential component of a corrosion-monitoring instrument that is expected to find wide application in industry. The performance of the switch-bank is discussed and its effect on the signals is illustrated.