基于双目视觉的接触网几何参数测量系统

接触网是在电气化铁路中沿钢轨上空之字形架设的,供受电弓取流的高压输电线,其担负着把从牵引变电所获得的电能直接输送给电力机车使用的重要任务。针对传统的接触网几何参数测量方法中测量效率低下、精度不高的问题,设计了一种快速、高精度测量系统。系统基于双目视觉测量原理,由指示激光器进行特征指引,通过两台高分辨率摄像机采集测量特征并进行图像处理和三维解算,实现接触网几何参数的实时测量。实验结果表明:系统测量的重复性精度可以达到1mm,实现了接触网几何参数的实时、可靠测量,为接触网的日常维护与检修提供了理论依据。     

圆柱工件几何参数的自动测量研究

针对圆柱工件在实际测量过程中测量速度慢、精度低的实际情况,本文介绍了一种利用几何位移光学精密测量完成圆柱工件几何参数测量的方法。该系统由机械系统、运动控制和数据采集系统、数据处理系统组成;利用激光位移传感器非接触测量的特点,对圆柱工件外表面几何信息进行采集;根据最小二乘法原理,计算机对测量数据进行处理,从而得到圆柱工件的外径、同轴度、高度等几何参数。该方法通过实验验证,目前已应用于生产中。     

基于无线传感技术的接触网导线接头及换相点温度监测系统

为了确保铁路接触网的稳定运行,设计了一种电气化铁路接触网导线接头及换相点温度监测系统,通过温度传感器检测高压部分的温度,采用两级无线数据传输网络实现温度的实时传输。第1级采用自由频段的短距离无线通讯方式,第2级采用不受地区限制的GPRS网络传输方式,用户通过远端数据监测中心软件可以方便地对监测信息进行远程管理,实现对各处接触网导线接头及换相点温度信息的调阅、查询和监测报警。     

一种高速铁路接触网参数无轨测量平台设计

随着我国经济和科技水平的快速发展,高速铁路施工技术也在不断地发展。无轨测量是在高速铁路施工过程中轨道没有铺设前进行的铁路接触网参数的测量方法,它可以做到基础一次性准确定位。将接触网架设与轨道铺设进行同步推进,使轨道铺设到哪里,接触网就可以架到哪里,弥补了我国高速铁路施工种铁路接触网参数测量技术的空白。文章就无轨测量技术进行研究与设计,分析其在地铁施工技术发展中的重要性。     

接触线几何参数CCD交汇测量分辨率及精度分析

采用双CCD交汇测量技术对电力机车接触导线磨损面边界点进行精确定位,可以实现导线高度、拉出值、磨损宽度等几何参数的非接触实时测量,而边界点定位精度及分辨率会受测量系统的光学参数、结构参数等的影响.基于交汇测量机理,推导出了接触线几何参数测量的表达式,详细分析了分辨率和测量精度与边界点位置、CCD像元尺寸、成像镜头焦距、两CCD之间的距离、交汇仰角等参数之间的关系,并进行了数值模拟.在此基础上,结合测量条件及技术指标完成了各参数的优化设计,得到了理论上能达到的最佳测量精度和分辨率,同时对测量装置的制作和安装提出了合理化的建议.     

核燃料芯块几何尺寸同步测量系统研究

几何尺寸和密度是影响核燃料燃烧效率和安全使用的重要因素。针对核燃料芯块的特殊性,研制了芯块几何尺寸、密度等多参数集成测量系统。该系统通过光学非接触法对芯块的高度和直径进行二维同步高精度测量,同时使用重量传感器测量重量,进而获取芯块密度参数。文中还对测量原理误差和系统误差进行了分析。实际测量结果表明,该系统相对于接触式测量,具有速度更快,精度更高,操作方便等优点,并可实现数据的同步采集、实时显示、处理、远程存储及超差提示、报表、系统设置、用户管理和权限设置等功能。     

铁路线路冲击状况检测系统的设计

为了对铁路线路的几何偏差进行检测和数据采集,给出了基于双轴加速度传感器ADXL210来设计铁路线路冲击状况检测系统的设计方法,同时给出了系统组成、工作原理以及系统的硬件电路.此外,该检测系统还可与上位机进行通讯,并将采样数据存储在上位机文件中,以便于数据的查询和分析,从而给铁路线路的长期正常运行和检查带来很大方便.     

智能传感器搏击市场

智能传感器搏击市场传感器是测量、控制和仪器技术中的关键部件。根据测量参数的不同,有机械参数型传感器、几何参数型传感器、热传感器、动力学传感器以及化学、气象和其它参数传感器。电子评价系统将传感器产生的微弱信号放大,并根据预定的参数触发致动器完成所设定的...     

基于线阵CCD的线路方向测量系统的开发

该系统硬件设备采用长距离准直激光光源、CCD图像传感器、旋转编码器、系统终端PC等器件,利用线阵CCD测量技术、数据处理技术、多信息传感融合技术等高新技术,能够对铁路路轨区段(长度≤200m)轨道几何形状进行高精度检测,将线路轨向测量结果直接数字化显示,为线路设备维修提供可靠的测量数据,解决了既有方法测量精度差、效率低的问题,能满足铁路工务系统作业要求、提高作业质量。     

电荷放大器对石英传感器动态特性的影响

用控制理论对压电石英传感器的等效电路、电压放大器、电荷放大器对压电式传感器动态特性的影响等进行了深入的分析与研究。通过对电压放大器与电荷放大器的系统传递函数的分析指出,压电电压测量系统可等效为1阶环节和2阶惯性环节。由于1阶系统的存在,导致系统不能测量直流信号和变化比较缓慢的信号。该电压测量系统的缺点可通过加电荷放大器来改善,此时压电电荷测量系统的稳态灵敏度为d/CF,它只依赖于电荷放大器的反馈电容,与石英晶体和连接导线的电容无关。从而指出为了充分利用石英传感器,应用时最好连接电荷放大器。     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.