绝对式容栅测量技术浅析

数显量具在各种制造业,尤其是传统机械制造业中,正以强劲的势头替代传统的机械量具和气动量具,成为生产现场主导测量器具.容栅数显位移传感技术和产品以其结构简单、对使用环境要求不高、测量速度快、能耗低等优点得到最为广泛的应用.介绍了相对式容栅数显量具的传感器结构、测量原理和相应的电路结构,指出相对式容栅测量系统使用过程中存在的问题,比较了绝对式容栅和相对式容栅的优缺点.介绍了绝对式容栅传感器和电路的结构,最后指出了国外绝对式容栅技术现状,以及国内绝对式容栅技术存在的差距.     

数显位移传感产品发展趋势概述

随着数控机床的不断发展,绝对式测量已经成为当前测量的主要趋势.国外的位移传感器已逐步实现了从增量式测量到跨八绝对式测量的进程,国内也需要加快进步,早日缩短与国外的差距.本文对各种数显位移传感产品如光栅传感器、容栅传感器、磁栅传感器、球栅传感器等的工作原理进行了简要的介绍,并对产品的发展趋势进行了概述.     

基于半导体硅片的容栅千分传感器的设计

容栅千分传感器广泛应用于位移测量中,设计的容栅千分传感器,将普通容栅传感器在线路板上的刻线划分移植到了半导体硅片上,利用了半导体的工艺技术,实现刻线划分的高精度、高密度,从而达到普通线路板无法达到的精度,将容栅传感器的分辨力提高至0.001 mm.     

基于单片机的轮对测量尺的研制

车辆轮对尺寸参数和踏面缺陷的检测是保障车辆运行安全的重要措施。介绍了一种基于容栅的车辆轮对测量尺检测系统。该系统运用精密容栅位移传感器,并结合精密算法,实现了轮缘厚度、轮缘高度、轮径等主要参数的自动检测。该系统的测量精度为0．01mm。实际应用表明,系统的检测精度和重复性可满足车辆段修现场使用要求。系统同时具有状态提示、数据统计分析、故障自动诊断、智能判断测量等功能,可及时与上位机通讯,实现数据共享。     

基于容栅技术的数显角度尺的研发

针对机械式角度尺存在的测量过程较为繁琐、测量结果不易读数、测量功能单一等问题,文章设计了一款数显角度尺.该数显角度尺利用容栅测量技术和单片机技术进行开发.基于容栅测量原理,设计开发符合要求的圆容栅传感器,该圆容栅传感器具有角位移信号输出功能,通过单片机对该位移信号进行数据运算及处理,从而实现0°～90°、90°～180...     

容栅传感器及其在目标运动转台中的应用

该文采用等效电路法研究了容栅传感器的数学模型。首先具体分析了容栅传感器的基本原理,依据其原理提出了合理的等效电路。同时给出了其测量专用集成电路的逻辑框图并简单介绍TN量电路的原理。出于经济性、简便性、实用性的考虑,在该文介绍的转台控制系统中,用容栅作为位置传感器,取代原来惯用的光电编码器和电位器。在系统中通过容栅数硅仪将容栅传感器测得的数据转换成RS-232串口信号,直接将转台各轴位移反馈信号送到工控机形成位置闭环,从而成功地控制各轴的运动。     

基于光场耦合的时栅位移传感器设计

为了实现制造成本低、易加工、高精度的位移测量,设计了一种光场耦合式的时栅位移传感器.介绍了利用基于交变光场的两路驻波合成电行波信号,并通过鉴相的方式实现空间位移转换的测量原理;完成了传感器的结构设计,给出了传感器的系统框图,具体分析了信号处理电路的功能.实验结果表明:光场耦合式的时栅位移传感器在108 mm范围内误差为±0. 5μm.     

基于提升小波变换的容栅传感器输出信号降噪

为了解决容栅传感器在测量转轴转速中的噪声抑制问题,在讨论容栅传感器测量转轴转速和提升小波变换基本原理的基础上,分别应用传统小波法和提升小波法对仿真信号和实测信号进行了降噪处理.结果表明,使用提升db5小波法对其进行软阈值降噪处理后能对容栅传感器的转速输出信号进行较准确的数值分析.已成功应用于容栅传感器的转速和扭矩测试,...     

基于容栅传感器和单片机的变形检测系统

文章介绍了基于容栅传感器和89C52单片机的位移检测系统的系统组成，重点分析了容栅数显卡尺信号转换原理及软件实现．该系统主要用于对结构的变形进行检测。     

柱栅传感器实验样机的研制

柱栅传感器是一种新型的直线位移数字式传感器,它来源于对直线式感应同步器的改进设想.柱栅概念样机研制的完成,证实了其设计思路的正确性与合理性.柱栅全连续化绕组的设计完全消除了分段绕组固有的端部效应.通过柱栅传感器实验样机的设计和制造及其相关测试,结果表明:该实验样机具有良好的空间正交性,测量系统误差小,达到了预期的效果,可以应用于精细位移测量.介绍了柱栅传感器实验样机的基本结构、研制和实验.进而验证了柱栅传感器的功能和使用性能.     

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。     

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。