电涡流间隙传感器的温度补偿

电涡流间隙传感器具有无接触测量、动态响应快和适应性好等特点,应用领域十分广泛,缺点是温度漂移较大。介绍了电涡流传感器工作原理,并分析了温度漂移的主要因素。建立了检测线圈的数学模型,通过温控试验证明了数学模型的正确性;利用差分方式抵消了检波电路参数的温度漂移,提高间隙信号输出的稳定性。通过试验对检测线圈和检波环节补偿电路进行验证,得出温度-检测线圈输出电压曲线,将补偿前和补偿后试验结果进行对比,满足JJG 644-90标准要求,温度漂移小于12.1%,证明了补偿方法的有效性。     

差动补偿型电涡流传感器及其计算机辅助设计

介绍一种电涡流位移传感器,该传感器采用差动补偿结构加之电路的对称设计,使其温度漂移和时间漂移完全抵消。还介绍了采用计算机辅助计算以确定最优工作点的方法。     

电涡流传感器温度漂移的综合补偿

在介绍电涡流传感器基本原理的基础上,分析了温度漂移产生的主要因素,并提出了一种温度漂移补偿的新方法,即利用负反馈组成闭环系统实现对温度漂移的综合补偿。实际测试结果表明:温度漂移综合补偿准确度可达0.41%,明显优于一般方法的补偿准确度。     

工业控制中电涡流传感器位移测量精度研究

针对电涡流传感器对受温度影响较大、导致严重的温度漂移的问题,提出了采用基于支持向量机算法的温度补偿模型。首先通过对电涡流传感器采用二维定标实验,通过温度箱改变温度,再利用温度传感器测试其温度,通过学习,建立支持向量机(Support Vector Machine,SVM)模型。通过对SVM中的核函数和参数的选取及优化,最终得到SVM的电涡流传感器的温度补偿模型。经过补偿之后,电涡流传感器的灵敏度温度系数和零位温度系数与未进行温补相比均提高了一个数量级,从而达到了对电涡流传感器温度补偿的目的,同时非线性也得到了校正。     

高速磁浮列车间隙传感器温度漂移的补偿

为了解决检测线圈电阻受温度影响而导致漂移补偿问题,设计分析了高速磁浮列车间隙传感器电路模型,设计补偿线圈,利用差分方式补偿了温度漂移,同时还分析得出了测量间隙对传感器温度灵敏度影响很小的结论,在传感器空载条件下的建立温度漂移修正表,利用该修正表来补偿传感器的温度漂移,通过这些措施,大大提高了间隙位移传感器输出信号的温度稳定性.     

一种新型间隙传感器研究

间隙传感器线圈电阻的温度漂移是导致传感器输出漂移的主要因素.为了抑制温度对间隙传感器的影响,设计新的传感器探头和测量电路;新的传感器探头跟现有传感器探头最大不同是在现有传感器探头的基础上增加了一个与传感器线圈完全一样的补偿线圈;并将补偿线圈和传感器线圈组成电桥测量电路.实验表明新传感器在0～80℃范围内温度漂移为0.08mm,温度稳定性好.     

涡流式厚度传感器温度漂移的综合补偿

介绍涡流传感器在线测量钢板厚度的基本原理,分析测量过程中温度漂移产生的主要原因,建立检测线圈的数学模型,提出采用双路差动综合补偿方式进行温度补偿的实施方案,实际测试结果表明补偿准确度达到要求.     

电涡流传感器温度漂移分析及补偿实现

大温差环境下检测线圈阻抗是导致传感器输出漂移的主要环节.对检测线圈阻抗温度漂移进行了理论分析,电阻温度漂移改变了阻抗,间隙对传感器温度灵敏度的影响很小,即不同间隙下温度漂移量认为是相同的.提出对检测线圈进行串联负温度系数(NTC)电阻补偿,并采用修正表算法来减小检测线圈带来的温度漂移.对漂移补偿后的传感器进行了实验验证.     

光纤耦合调频差动式电涡流传感器的研究

本文介绍频率调制式电涡流传感器的原理、探头的敏感线圈与参考线圈差动结构的模式,以及测量信号的远距离光纤传输等方法,并讨论了这些技术措施对测量系统的稳定性,温度漂移抑制、抗干扰等性能指标的改善.     

光纤祸合调频差动式电涡流传感器的研究

本文介绍频率调制式电涡流传感器的原理、 探头的敏感线圈与参考线圈差动结构 的模式, 以及浏? 信号的远距离光纤传翰等方法, 并讨论了这些技术措施对浏全系统的稳 定性, 温度漂移抑制、杭干扰等性能指标的改善%     

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。