西门子变频器的应用 第5讲 MM440变频器与HMI直接通讯

西门子自动化产品包括PLC、触摸屏和变频器,常见的控制方式是触摸屏与PLC相连,PLC与变频器相连,而本文主要阐述的是西门子MM4系列变频器与HMI的直接通讯应用,实践证明该方式是有效的。     

西门子PLC和变频器在煤气加压站的应用

详细介绍了西门子可编程序控制器（PLC）的功能和特点，通过西门子PLC和变频器相配合，提高了控制的精确度。以西门子PLC和变频器在大型钢铁厂中煤气加压站的应用为例。介绍了西门子PLC实现控制的方法和实施中应注意的问题。     

PLC与变频器的关联竞争

为用户提供解决方案，而不是单独的控制元件将会有显而易见的竞争力。尤其在小型的控制系统，即小型PLC搭配小功率变频器，当然还有HMI，甚至包含伺服，越来越成为OEM客户的需求趋向。为此，判断变频器供应商的竞争力，尤其是在OEM市场，应该将目光从变频器的领域放宽到整个控制系统的高度，即与PLC结合在一起的竞争力。     

西门子6SE70变频器在纸机控制系统中的应用

本文介绍造纸生产线电气传动控制系统的特点,以西门子公司6SE70矢量控制变频器为驱动装置,西门子PLC300为控制核心,根据西门子USS协议格式,实现PLC与西门子6SE70矢量变频器的通信,纸机的速度链结构、负荷分配控制等功能。在造纸机控制系统中取得了较高的控制精度和稳定性,充分满足生产过程的需要。     

西门子PLC与三菱变频器数据通讯的实现

本文以三菱公司的FR—A740变频器为例,讨论了西门子S7—300系列PLC与三菱FR—A740变频器通过Profibus—DP现场总线实现数据通讯的方法。通过它在某生产线中的应用,从而使该方法得到了实践验证,为后续建立变频器的集中监控打下了基础。     

西门子6SE70变频器在纸机控制系统中的应用

本文介绍造纸生产线电气传动控制系统的特点,以西门子公司6SE70矢量控制变频器为驱动装置,西门子PLC300为控制核心,根据西门子USS协议格式,实现PLC与西门子6SE70矢量变频器的通信,纸机的速度链结构、负荷分配控制等功能.在造纸机控制系统中取得了较高的控制精度和稳定性,充分满足生产过程的需要.     

探究变频器与PLC组合控制系统的应用

随着科学技术的不断发展应用,自动化控制系统的研究也取得了一定的成绩。而变频器和PLC组合系统的应用也得到了相应的重视,在工业的生产实践与研究中,不断涌现出多种实用型的变频器与PLC组合系统的控制方式,给工业自动化的生产控制带来了基本的技术保障。变频器与PLC组合控制系统的应用可以应用到液体混合等工作上,则本文通过介绍变频器和PLC的组合控制系统在液体混合上的应用来探究变频器与PLC组合控制系统的应用。     

西门子PLC与变频器通信控制电机恒转速

文中首先介绍了选题背景,接着介绍了变频调速,PLC的相关知识,最后阐述了PLC与变频器如何通过通信来实现刷辊电机的恒转速控制的。     

西门子PLC的工程应用系列讲座 第3讲 西门子PLC与施耐德电气变频器在复合机上的应用

PROFIBUS-DP是一种经过优化的通讯协议,有较高的数据传输率,适用于系统和外部设备之间的通信。本文主要阐述了西门子PLC与施耐德电气变频器在复合机上的应用。     

台达机电产品在塑料薄膜生产线上的应用

本文主要介绍了台达机电产品（触摸屏、PLC、变频器、温控器等）在塑料薄膜生产线上的整合应用。该控制系统操作界面友好简单,结合台达HMI、PLC和变频器等工控产品,实现了设备的技术升级与高效节能,体现出台达自动化产品较高的性价比。运行实践证明,台达产品稳定可靠,控制效率高,值得业界同行借鉴和推广。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

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.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

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。