机车涂装线PLC控制系统设计

介绍了机车涂装线控制系统的原理,根据系统设计要求提出控制方案,设计了基于三菱FX2N可编程控制器和三菱AG-OT900触摸屏的涂装线控制系统,完成控制系统的硬件设计和软件设计,系统实现对机车涂装生产线过程的手动和自动控制,与PLC可编程控制机器人对话,实现机车涂装生产线自动排风、自动控制温度,遇到故障系统自动停止运行,完成对涂装生产现场的实时监控和报警;该设备现场运行情况表明,排风和温度控制精度高,运行可靠,满足系统各项要求.     

PLC和触摸屏在金相切割机中的应用

本文以金相切割机控制系统的改造为例,介绍了控制系统的组成.在系统改造中,以PLC作为控制系统的核心,以触摸屏作为人机界面简单直观,易于操作.并着重介绍了PLC和触摸屏的硬件和软件设计.系统试用表明PLC的使用提高了控制系统的稳定性和抗干扰能力,触摸屏的使用减少了大量的硬件设施以及由此带来的故障.     

矿用蓄电池电动机车PLC程序模块化设计

针对PLC程序的模块化需求问题,介绍了一种蓄电池电动机车控制系统PLC程序的模块化设计方法,给出了蓄电池电动机车的工作过程及其控制系统的硬件结构和软件流程,并以行车功能块和可视化模块为例,详细介绍了蓄电池电动机车控制系统PLC程序的模块化设计实现。与传统的PLC编程方法相比,模块化编程思想使程序结构清晰,功能独立,编写简单,有利于整个控制系统的开发和调试。     

PLC控制系统故障检测

为了提高PLC控制系统的可靠性，本文分析了PLC控制系统在运行过程中常见的故障，并提出多种PLC控制系统故障检测的技术措施。     

车床CA6140电气控制系统的PLC改造

针对传统的继电器控制系统故障频繁的特点,对CA6140车床的电气控制系统进行了技术改造,采用可编程逻辑控制器（PLC）代替原有的继电器,设计了PLC控制系统的硬件组成及其控制程序。改造后车床运行稳定,降低了故障率,提高了使用效率。     

现代数控机床PLC相关故障诊断及维修

PLC作为现代数控机床控制系统的一部分,在CNC与机床之间发挥控制功能.在实践应用中,它能够响应输入的离散信息,并在系统内部进行逻辑运算,最后作出针对性的动作.数控机床中的LPC,能够及时发现系统潜在故障,并对故障产生原因予以诊断,为维修人员维修提供支持.文章从PLC技术内涵及信息交换方式入手,并对现代数控机床PLC故障诊断及维修进行分析和研究.     

基于虚拟仪器技术实现PLC控制系统的状态监测和故障诊断

在PLC控制系统的故障中，以传感器和执行器故障居多，一般还具备隐蔽性和突发性较强的特点，单纯依靠简单的测试工具和人工检查等传统手段难以及时发现和解决。研究并实现了在LabVIEW6．1编程环境下计算机与PLC的串行通信，利用虚拟仪器技术构建了基于RS485／232总线的PLC控制系统的状态监测和故障诊断平台，通过对系统操作状态、传感器和执行器状态、生产工艺流程状态的监测，实现对整个控制系统的状态监测和故障诊断。在工业现场的成功应用验证了该系统优于传统手段的结论，并且具有有效性和广阔的发展前景。     

高压直流输电换流阀冷却系统内外冷通信优化方案

目前,阀冷系统的内冷与外冷控制系统在距离上分布较远,普遍采用通信光纤进行连接和数据通信。为防止因设备故障、外力破坏等因素造成内外冷控制系统之间通信中断,进而导致换流阀因阀冷系统失去冷却能力而闭锁的严重故障,给出一种适用于内外冷控制系统之间通信故障的优化解决方案。其在外冷控制系统中设置通信故障检测回路和快速响应控制回路,并通过PLC软件对通信状态进行实时检测与控制。当通信故障检测回路检测到内外冷控制系统通信中断时,可通过快速响应控制回路迅速作出响应,进而控制中间继电器启动外冷系统的换热设备。该方案不仅能够保持阀冷系统的正常冷却能力,还可有效提高阀冷系统的可靠性。     

DF12型机车恒低速PLC控制系统

简要介绍了DF12型机车恒低速PLC控制系统的研究情况、系统构成与功能及工作原理等。装有该系统的机车在神华西部铁路有限公司装煤站的实际使用表明,该系统稳定可靠,使用效果良好。     

冗余技术提高PLC控制系统可靠性的研究

针对工业现场对PLC控制系统可靠性提出更高的要求,提出利用冗余技术提高其可靠性。分析了硬件冗余和软件冗余在PLC控制系统中的应用,详细阐述了PLC控制器、输入输出口、通讯网络和电源各自的冗余方法,并着重以西门子300/400系列PLC为例进行了软硬件冗余的架构和原理分析。最后对冗余控制系统的可靠性进行分析,结果表明,使用冗余技术可使PLC控制系统的可靠性得到明显提高。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.