电涡流传感器热稳定性标定技术

介绍电涡流传感器位移测量原理,分析温度变化时传感器线圈和探头热胀冷缩在测量位移过程中造成的温度漂移现象.针对传感器的温漂,研制出具有温度补偿功能的电涡流传感器热稳定性标定装置,对传感器输出电压进行温度补偿,减小温度变化对传感器输出电压的影响.同时介绍利用该装置进行温度标定的实现方法,并进行实验验证,实现固定位移条件下环境温度变化时对电涡流传感器输出电压的标定,与无温度补偿时输出电压对比,电压变化量减小了近50%.     

基于遗传算法的RBF神经网络在涡流传感器非线性补偿中应用

为了解决涡流传感器的非线性问题,应用遗传算法(GA)训练径向基函数(RBF)神经网络(NN)实现其非线性补偿.介绍非线性补偿的原理和网络训练方法.从实测数据出发,建立了涡流传感器的非线性补偿模型.该方法能同时优化网络结构和参数,具有全局寻优能力,补偿精度高、鲁棒性好、网络训练速度快、能实现在线软补偿.实验结果表明,所采用的涡流传感器非线性补偿方法是有效的和可行的.补偿后,最大非线性误差在0.5%范围内,具有良好的线性.     

MATLAB在电涡流传感器标定中的应用

MATLAB作为数学工具,在各行各业发挥着巨大作用。而电涡传感器作为一种非接触式的位移传感器,具有灵敏度高、线性范围大、频率范围宽,抗干扰能力强等优点。本文首先介绍了电涡流传感器的基本原理。并在传感器的后续标定过程中采用MATLAB数学工具对采集到的数据进行拟合运算,得到电涡流传感器的非线性度特性,对传感器的检测有很大帮助。     

基于单片机的电涡流式微位移传感器测量系统的研究

在现代社会,信息充斥在人们生活的方方面面。对外界信息的获取至关重要,本论文主要介绍的是电涡流式位移传感器。电涡流式位移传感器属于电感式位移传感器的一种,是基于电涡流效应而工作的传感器,具有很多优点:高分辨率、高可靠性、较宽的频率响应以及较高的灵敏度等等。该传感器还具有很强的抗干扰能力,相比而言,传统的传感器具有非线性误差,要求工作环境恒定或者价格较高。本论文主要介绍了传统传感器的发展历程,进而介绍了电涡流式微位移传感器的测量原理和优势,并基于单片机设计了测量系统。     

电子元件、组件

TM4012005040435电涡流传感器温度漂移的综合补偿/王现军,宋豫全,杜保强(郑州大学信息工程学院)//传感器技术.―2004,23(2).―53～55.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.图5表2参3TM422005040436以模糊聚类标准谱与灰色关联序诊断变压器内部故障的方法研究/李俭,孙才新,廖瑞金,周湶(重庆大学高电压与电工新技术教育部重点实验室)//仪…     

用于矢量水听器的电涡流传感器的研究

该文分析了用于位移矢量水听器的电涡流传感器的工作原理,对电涡流传感器的传感系数进行研究,得到了电涡流探头线圈的各参数对传感系数的影响,并通过实验对传感系数的计算模型进行了验证。对电涡流位移传感器的指向性分辨力进行研究。运用有限元软件对其进行仿真,得到主轴方向上传感系数与主轴正交方向上传感系数之比,该比值随着金属被测体半径的增大而增大,且均大于20 dB,满足矢量水听器指向性分辨力的要求。     

电涡流传感器温漂的综合补偿

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,并提出了一种温漂补偿的新方法,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,温漂综合补偿精度可达0.41%,明显优于一般方法的补偿精度.     

基于灰色神经网络的压力传感器温度补偿模型

压力传感器的输出随温度呈非线性变化,同时含有较大的随机噪声。针对BP神经网络对压力传感器温度补偿建模时误差较大的问题,提出了基于灰色模型和BP神经网络的压力传感器温度补偿模型。首先,用灰色模型对数据进行预处理,以减小原始数据的噪声;然后,用降噪后的样本数据作为BP神经网络的输入进行训练。在相同的训练次数下训练误差可减小一个数量级。结果表明,采用该模型补偿后的压力传感器补偿精度明显优于BP网络模型。     

基于BP神经网络的一种传感器温度补偿方法

简单介绍了硅压阻式传感器温度误差产生的原因及其特点,提出了一种利用BP神经网络对其温度误差及非线性误差进行补偿的方法.根据传感器温度误差的特点设计了一个多层的BP神经网络,其中传感器测试电路中四臂电桥的桥路电压和未经补偿的传感器的输出作为神经网络的两个输入.利用Matlab对该网络进行训练,得到了网络的权值和阚值.经过...     

一种屏蔽式电涡流传感器的研制

某构件为多层窄间隙结构的容器装置,为测试在具有一定压力的高速流场中流体诱发的内层板振动情况,基于电涡流原理设计了一种屏蔽式电涡流传感器,完成了屏蔽式电涡流传感器的探头线圈参数和探头壳体结构参数的优化设计、装配调试和第三方校准。试验结果表明:研制的屏蔽式电涡流传感器,在不干扰"流场",对装置结构不构成影响的前提下,实现了板间窄间隙振动的测试,传感器可靠有效。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.