基于COMSOL和iSIGHT的涡流传感器的仿真和优化

电磁场的分布情况对磁悬浮轴承电涡流位移传感器的灵敏度和线性度有重要影响.应用COM-SOL Multiphysics的AC/DC模块建立电涡流位移传感器模型,并进行仿真分析.进一步应用iSIGHT对传感器检测线圈的结构参数进行了优化设计,检测线圈的线性度和灵敏度得到了改善.COMSOL Multiphysics与iSI...     

电涡流位移传感器线圈电磁场仿真分析

由于电涡流传感器的探头参数对其性能的影响比较显著,设计电涡流传感器的关键在于对探头线圈进行优化。采用有限元技术(AnsoftM axwell软件)对包括线圈和金属靶板的电涡流位移传感器进行电磁场数值仿真,得到了激励线圈的磁力线和被测靶板中电涡流的密度分布。并通过线圈等效阻抗的实验与计算结果定量比较,验证了仿真分析过程的正确性,为进一步完善传感器的理论分析和优化设计打下了基础。     

基于二阶矢量位的线圈横向移动三维涡流理论建模

针对电涡流传感器探头线圈相对导体横向移动时阻抗变化的涡流问题,以二阶矢量位电磁理论为基础,在直角坐标系下,推导出线圈相对导体横向移动时的阻抗及阻抗变化量公式,建立其电磁场三维涡流理论模型,且通过试验验证了模型的正确性.使用Mathematice软件建立模型计算分析线圈几何尺寸(内径、厚度、线宽、线间距)对传感器灵敏度的影响,为合理选择线圈参数和优化传感器性能提供参考.     

电涡流传感器线圈参数对传感器性能的影响

介绍电涡流传感器的工作原理,以及传感器线性测量范围及灵敏度与线圈参数的关系。研究了改变线圈截面形状及参数变化对传感器性能和灵敏度的影响,得到它们之间的定性关系,从而对传感器的优化设计提供理论依据。     

地下金属管线无损检测仪中涡流传感器的阻抗分析

根据电磁涡流检测原理,对地下金属管线无损检测仪中的涡流传感器进行设计,并针对无损检测仪中涡流传感器线圈结构参数对传感器性能的影响进行分析。建立空心线圈的有限元模型,对线圈尺寸影响因素进行了分析。针对不同的结构参数,确定磁芯半径与传感器线圈阻抗变化的关系式,确定传感器线圈参数对于传感器线性度和灵敏度的影响,为涡流传感器的...     

电感式磨粒传感器中非铁磁质磨粒的磁场特性

在电感式磨粒传感器中,非铁磁质磨粒主要通过涡流效应改变传感器线圈的磁场分布,进而改变线圈的等效电感。建立传感器线圈时谐电磁场与非铁磁质球磨粒耦合关系的有限元模型,模型计算结果表明:磨粒感应出的涡流场减小了磨粒内部的磁感应强度,同时改变了磨粒外部磁感应强度;磨粒引起传感器线圈电感变化率随线圈激励频率的增加而增大,并趋向于一极限值;线圈电感变化率随磨粒半径的减小而迅速衰减。实验研究的结果证明了模型计算的正确性。     

超薄平面结构电涡流传感器的研究

介绍用集成电路微细加工技术研制出的一种新型超薄平面结构的电涡流传感器探头。用理论模拟对线圈半径与绕向进行设计，并配制了适宜的二次电路，制造出微位移测试样机。同传统结构的电涡传感器探头相比，灵敏度提高了１６％，线性度改善２％。     

基于三维有限元的电涡流传感器参数的仿真研究

电涡流传感器的参数变化对其性能的影响是比较显著的,因此设计电涡流传感器的关键在于对传感器参数进行优化,采用有限元技术(ANSYS软件)对不同形状的空心平面线圈的三维电磁模型进行仿真分析,在得到各种电感曲线的基础上．定性地分析了几种主要参数变化对变面积式电涡流传感器的影响,结果表明,为了提高传感器测量灵敏度,线圈应采用较小的长度、较大的宽度和尽可能小的间隙,该项研究成果为传感器优化分析提供了有利的方法和手段。     

基于三维有限元的电涡流传感器结构的仿真研究

本文针对当前普通电涡流传感器存在的两个弊端着手,提出了一种新的设计方案：在空心线圈中加入了一种U型铁氧体材料的磁芯,并利用电磁场计算软件ANSYS,在其环境下建立了三维模型（three—dimensional model）,通过划分网格、加载边界条件等计算出了其磁场能量值。通过与条型磁芯在数值上和图形上的直观比较,表明了在普通电涡流传感器中加入U型磁芯的优越性。文章最后还对U型磁芯应用于曲面检测时的情况做了实例分析,验证了U型磁芯的实用性。为电涡流传感器的优化设计提供了参考。     

基于线圈互感的阵列涡流传感器优化设计

线圈单元间互感一直是影响接收/发射式阵列涡流传感器准确性的干扰因素,工程实际中采用多种方法减弱线圈单元间互感对检测线圈单元的影响,但线圈单元间互感中包含缺陷信息,有效利用线圈单元间互感可以获得缺陷更多的信息,有利于缺陷的评估.运用ANSYS软件进行三维有限元仿真,利用线圈单元间互感研究了线圈单元相关参数对阵列涡流传感器检测灵敏度和空间分辨率的影响,理论上为基于线圈单元间互感的阵列涡流传感器的优化设计提供了参考.     

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。     

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.     

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.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

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.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

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     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.