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基于CPLD的全桥SPWM逆变控制波形生成 被引量:5
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作者 张贤涛 于生宝 +1 位作者 姜卓娇 韦建荣 《电力电子技术》 CSCD 北大核心 2006年第5期118-120,共3页
介绍了SPWM控制的基本原理,详细分析了规则采样法生成SPWM控制波形的计算过程,得出了简单的SPWM工程计算公式。采用有限状态机设计方法,使用VHDL硬件描述语言编程,并在EDA工具软件平台上进行了仿真和下载。最终结合EPM7128实现了产生50H... 介绍了SPWM控制的基本原理,详细分析了规则采样法生成SPWM控制波形的计算过程,得出了简单的SPWM工程计算公式。采用有限状态机设计方法,使用VHDL硬件描述语言编程,并在EDA工具软件平台上进行了仿真和下载。最终结合EPM7128实现了产生50Hz工频逆变所需要的全桥SPWM控制波形。 展开更多
关键词 逆变 脉冲宽度调制 制/可编程逻辑控
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自来水厂送水泵房控制系统振荡的原因及对策
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作者 陈汉洌 《变频器世界》 2004年第6期106-108,共3页
简述自来水厂送水泵房控制系统由于变频泵选型不当而造成的振荡原因,并提出一些对策。
关键词 自来水厂 送水泵房 制系统 振荡 可编程逻辑控削器
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花园水电站综合自动化系统的设计与应用 被引量:8
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作者 王军辉 《电网与清洁能源》 2013年第11期126-130,共5页
以水电站"无人或少人值守"的原则作为设计主要目标,对花园水电站的综合自动化系统设计及实现方式进行了简单介绍。分别从系统结构、硬件设计及软件设计等几个方面,详细论述了该水电站综合自动化系统的设计过程。该电站的综合... 以水电站"无人或少人值守"的原则作为设计主要目标,对花园水电站的综合自动化系统设计及实现方式进行了简单介绍。分别从系统结构、硬件设计及软件设计等几个方面,详细论述了该水电站综合自动化系统的设计过程。该电站的综合自动化系统采用基于美国GE公司90-70系列的可编程逻辑控制器(PLC),包括了计算机监控、继电保护和发电机励磁等功能,经过各项试验验证,该电站的综合自动化系统达到了要求的设计目标。 展开更多
关键词 水电站 综合自动化系统 硬件 软件 可编程逻辑控 制器
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基于DMR标准的TPC信道编解码设计
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作者 权进国 陈海飞 林孝康 《微处理机》 2012年第3期29-31,36,共4页
根据DMR标准,设计出Turbo乘积码信道编解码系统。详细介绍了信道编解码系统的整体流程图,以及内码汉明编解码单元的实现。在标准算法基础上对电路结构进行优化处理,使该系统可以保证在较高的实时性和占用硬件资源不大的条件下,符合DMR... 根据DMR标准,设计出Turbo乘积码信道编解码系统。详细介绍了信道编解码系统的整体流程图,以及内码汉明编解码单元的实现。在标准算法基础上对电路结构进行优化处理,使该系统可以保证在较高的实时性和占用硬件资源不大的条件下,符合DMR标准的应用。 展开更多
关键词 DMR标准 信道编解码 TURBO乘积码 汉明码 可编程逻辑控
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基于EPLD技术的多路视频监视系统
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作者 王鲁平 李飚 《电视技术》 北大核心 2001年第4期85-85,87,共2页
应用ALTER公司生产的MAX9000S系列的EPLD器件EPM9560-40设计开发了一个多路视频监视系统,由于应用EPLD技术,该系统集成度高,结构小巧,可以在一台监示器上显示多路视频,所以具有较高的实用价值。
关键词 可编程逻辑阵列 视频采集 多路视频监视系统
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Gas pipeline explosion resistance technology 被引量:1
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作者 Zhao ZHU Zhen-Yuan JIA Kui-Jun WANG 《Journal of Coal Science & Engineering(China)》 2013年第3期353-357,共5页
Based on the features and requirements of gas drainage system, an optimized explosion resistance technology is done after a comprehensive analysis and research about the triple IR (Infrared Ray) flame detection tech... Based on the features and requirements of gas drainage system, an optimized explosion resistance technology is done after a comprehensive analysis and research about the triple IR (Infrared Ray) flame detection technology, explosion resistance valve technology and explosion resistance control technology. An intelligent PLC (Programmable Logic Controller) resistance control system is designed which can cut offthe gas branch quickly and accurately, and the controller have automatic pressure maintaining function, valve rotation limit function, remote and local control interlock function. The reliability and rationality of explosion resistance technology is verified by gas pipeline explosion propagation and resistance simulation test. Overall response time of explosion resistance system is less than 100ms, and the spread of fire in gas pipeline can be prevented effectively. 展开更多
关键词 explosion resistance technology flame detection fast shut-off valve intelligent control
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Simulation Based Synthesis, Design and Optimization of Actual Pressure Swing Adsorption (PSA) Unit
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作者 Rajasree Retnamma Arun Sadashio Moharir 《Journal of Chemistry and Chemical Engineering》 2012年第4期336-345,共10页
The present study demonstrates the potential of the simulation based on-line synthesis, design and optimization strategy for pressure swing adsorption (PSA) processes developed in our earlier study by implementing o... The present study demonstrates the potential of the simulation based on-line synthesis, design and optimization strategy for pressure swing adsorption (PSA) processes developed in our earlier study by implementing on an actual two-bed unit. The unit is very flexible and allows process synthesis from the PSA cycle configuration point of view. The model parameters are regressed and updated using live experimental data. The on-line monitoring and controlling of the operating parameters and operating configurations are done by multi-loop processor programmable logic controller. Separation of air into nitrogen free oxygen as raffinate stream and enriched nitrogen as extract stream using 5A zeolite as adsorbent has been chosen as a specific system for implementing the strategy. The philosophy of the typical optimization and process synthesis exercise implemented on the unit is described. The results show the successful implementation of the developed strategy on the two-bed O2-PSA unit and the application of this general approach to commercial PSA processes. 展开更多
关键词 PSA process synthesis DESIGN OPTIMIZATION simulation.
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Study on Position Control System with Programmable Logic Controller
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作者 唐海燕 卢仁军 郝云鹏 《Journal of China University of Mining and Technology》 2003年第1期108-112,共5页
To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a math... To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements. 展开更多
关键词 elliptical tracking position control mathematical model PLC
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Automation System for Quality Control in Manufacture of Iodine-125 Sealed Sources Used in Brachytherapy
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作者 Samir Luiz Somessari Anselmo Feher Francisco Edmundo Sprenger Maria Elisa Chuery Martins Rostelato Carlos A. Zeituni Joao A. Moura Osvaldo Luiz da Costa Wilson Aparecido Parejo Calvo 《Journal of Physical Science and Application》 2013年第6期380-386,共7页
The objective of this work is to develop an automation system for quality control (QC) in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding (LBW). These sources, also ... The objective of this work is to develop an automation system for quality control (QC) in the production of Iodine-125 sealed sources, after undergoing the process of laser beam welding (LBW). These sources, also known as Iodine-125 seeds are used, successfully, in the treatment of cancer by brachytherapy, with low-dose rates. Each small seed is composed of a welded titanium capsule with 0.8 mm diameter and 4.5 mm in length, containing Iodine-125 adsorbed on an internal silver wire. The seeds are implanted in the human prostate to irradiate the tumor and treat the cancerous cells. The technology to automate the quality control system in the manufacture of lodine-125 seeds consists in developing and associate mechanical parts, electronic components and pneumatic circuits to control machines and processes. The automation technology for Iodine-125 seed production developed in this work employs programmable logic controller (PLC), step motors, drivers of control, electrical-electronic interfaces, photoelectric sensors, interfaces of communication and software development. Industrial automation plays an important role in the production of Iodine-125 seeds, with higher productivity and high standard of quality, facilitating the implementation and operation of processes with good manufacturing practices (GMP). Nowadays, the Radiation Technology Centre at IPEN-CNEN/SP imports and distributes 36,000 lodine-125 seeds per year for clinics and hospitals in the whole country. However, the Brazilian potential market is of 8,000 lodine-125 seeds per month. Therefore, the local production of these radioactive seeds has become a priority for the Institute, aiming to reduce the price and increase the supply to the population in Brazil. 展开更多
关键词 Iodine-125 seeds quality control BRACHYTHERAPY automation system (Nd:YAG) laser welding automation system.
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Commissioning Status of NSLS-II Vacuum Control System
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作者 Huijuan Xu Hsiao-chaun Hseuh Shuwei Leng Douglas T Zigrosser 《Journal of Physical Science and Application》 2015年第2期123-127,共5页
The NSLS-II (National Synchrotron Light Source II) is a state-of-the-art 3 GeV third generation light source currently under integrated testing and commissioning at Brook_haven National Laboratory. The vacuum system... The NSLS-II (National Synchrotron Light Source II) is a state-of-the-art 3 GeV third generation light source currently under integrated testing and commissioning at Brook_haven National Laboratory. The vacuum systems are monitored by vacuum gauges and ion pump current. The gate valves are controlled by PLC (programmable logic controllers) using voting scheme. EPICS (Experimental Physics and Industrial Control System) application codes provide the high level monitoring and control through the input-output controllers. This paper will discuss the commissioning status of the various aspects of vacuum control system. 展开更多
关键词 NSLS-II VACUUM control system commissioning status.
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Fully Integrated Machine Control for Ultra Precision Machining
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《Journal of Mechanics Engineering and Automation》 2013年第8期465-472,共8页
To meet the demands for highly advanced components with ultra precise contour accuracy and optical surface quality arising in the fields of photonics and optics, automotive, medical applications and biotechnology, con... To meet the demands for highly advanced components with ultra precise contour accuracy and optical surface quality arising in the fields of photonics and optics, automotive, medical applications and biotechnology, consumer electronics and renewable energy, more advanced production machines and processes have to be developed. As the complexity of machine tools rises steadily, the automation of manufacture increases rapidly, processes become more integrated and cycle times have to be reduced significantly, challenges of engineering efficient machine tools with respect to these demands expand every day. Especially the manufacture of freeform geometries with non-continuous and asymmetric surfaces requires advanced diamond machining strategies involving highly dynamic axes movements with a high bandwidth and position accuracy. Ultra precision lathes additionally equipped with Slow Tool and Fast Tool systems can be regarded as state-of-the-art machines achieving the objectives of high quality optical components. The mechanical design of such ultra precision machine tools as well as the mechanical integration of additional highly dynamic axes are very well understood today. In contrast to that, neither advanced control strategies for ultra precision machining nor the control integration of additional Fast Tool systems have been sufficiently developed yet. Considering a complex machine setup as a mechatronic system, it becomes obvious that enhancements to further increase the achievable form accuracy and surface quality and at the same time decrease cycle times and error sensitivity can only be accomplished by innovative, integrated control systems. At the Fraunhofer Institute for Production Technology IPT a novel, fully integrated control approach has been developed to overcome the drawbacks of state-of-the-art machine controls for ultra precision processes. Current control systems are often realized as decentralized solutions consisting of various computational hardware components for setpoint generation, machine control, HMI (human machine interface), Slow Tool control and Fast Tool control. While implementing such a distributed control strategy, many disadvantages arise in terms of complex communication interfaces, discontinuous safety structures, synchronization of cycle times and the machining accuracy as a whole. The novel control approach has been developed as a fully integrated machine control including standard CNC (computer numerical control) and PLC (programmable logic controller) functionality, advanced setpoint generation methods, an extended HMI as well as an FPGA (field programmable gate array)-based controller for a voice coil driven Slow Tool and a piezo driven Fast Tool axis. As the new control system has been implemented as a fully integrated platform using digital communication via EtherCAT, a continuous safety strategy could be realized, the error sensitivity and EMC susceptibility could be significantly decreased and the overall process accuracy from setpoint generation over path interpolation to axes movements could be enhanced. The novel control at the same time offers additional possibilities of automation, process integration, online data acquisition and evaluation as well as error compensation methods. 展开更多
关键词 Ultra precision machining fully integrated control highly dynamic axes FPGA EtherCAT.
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Advanced Control System Development on the Basis of Festo Training Laboratory "Compact Workstation"
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作者 Vladimir Skopis Igors Uteshevs Aivars Pumpurs 《Journal of Energy and Power Engineering》 2014年第5期966-972,共7页
This article describes the development of automatic control system on the basis of Festo "Compact Workstation" training stand. Such control systems are used in different branches of industry and infrastructure inclu... This article describes the development of automatic control system on the basis of Festo "Compact Workstation" training stand. Such control systems are used in different branches of industry and infrastructure including oil industry, chemical industry, water treatment, canalization and others. The stand allows realizing level, flow, pressure and temperature control systems, using pump, valves, discrete and analog sensors. Level control system is described in this work. PID (proportional integral derivative) controllers are used in these systems. Control is switched on and off and the parameters of control systems are changed by means of SCADA (supervisory control and data acquisition) system. During real technological processes, these actions are performed by the operator. The algorithm of the control system is realized using PLC (programmable logic controller). At the end of the article conclusions about the research are drawn. 展开更多
关键词 PLC SCADA PID controller liquid level control.
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NIPAD: a non-invasive power-based anomaly detection scheme for programmable logic controllers 被引量:4
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作者 Yu-jun XIAO Wen-yuan XU +2 位作者 Zhen-hua JIA Zhuo-ran MA Dong-lian QI 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2017年第4期519-534,共16页
Industrial control systems (ICSs) are widely used in critical infrastructures, making them popular targets for attacks to cause catastrophic physical damage. As one of the most critical components in ICSs, the progr... Industrial control systems (ICSs) are widely used in critical infrastructures, making them popular targets for attacks to cause catastrophic physical damage. As one of the most critical components in ICSs, the programmable logic controller (PLC) controls the actuators directly. A PLC executing a malicious program can cause significant property loss or even casualties. The number of attacks targeted at PLCs has increased noticeably over the last few years, exposing the vulnerability of the PLC and the importance of PLC protection. Unfortunately, PLCs cannot be protected by traditional intrusion detection systems or antivirus software. Thus, an effective method for PLC protection is yet to be designed. Motivated by these concerns, we propose a non-invasive power- based anomaly detection scheme for PLCs. The basic idea is to detect malicious software execution in a PLC through analyzing its power consumption, which is measured by inserting a shunt resistor in series with the CPU in a PLC while it is executing instructions. To analyze the power measurements, we extract a discriminative feature set from the power trace, and then train a long short-term memory (LSTM) neural network with the features of normal samples to predict the next time step of a normal sample. Finally, an abnormal sample is identified through comparing the predicted sample and the actual sample. The advantages of our method are that it requires no software modification on the original system and is able to detect unknown attacks effectively. The method is evaluated on a lab testbed, and for a trojan attack whose difference from the normal program is around 0.63%, the detection accuracy reaches 99.83%. 展开更多
关键词 Industrial control system Programmable logic controller Side-channel Anomaly detection Long short-term memory neural networks
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