二维激光图像挠度/位移测量系统的信号预处理

为解决二维激光图像挠度/位移测量系统测量数据不稳定的问题,分析了光斑图像不稳定的因素,指出了影响光斑稳定的原因,提出了图像预调整、颜色识别、阈值判定和滤波的处理方法.这些预处理方法有效地消除了自然光线、散射光线和衍射光线对系统的干扰,使激光光斑图像保持稳定,起到提高系统精度的作用,得到了较为理想的结果.     

一种远距离激光位移/挠度测量系统的设计

描述一种能够测量远处物体的位移或者挠度的远距离激光位移/挠度测量系统,并对该系统的结构、工作原理以及硬件和软件部分进行了详细的介绍,给出了实验测试结果.该系统由一个激光光源和一个线性测量系统组成.激光光束首先经过校准,然后聚焦在测量系统上来进行长距离精确测量.激光光源和测量系统之间的相对位移反映出了物体的位移或者挠度.该系统使用了一定的信号和图像处理方法来提高系统的精度和准确性,并且使用了长距离无线数字通信,提高了信号传输的稳定性、安全性,避免了长距离信号线布线的繁琐.该系统还使用单片机系统和8位数码管结合的方式进行数据计算和显示,不再依赖计算机,使测量系统具有更好的便携性.由于该测量系统具有高精度、高准确度的特点并且结构简单、成本低廉,将有良好的应用前景.     

一种激光图像挠度测量方法

分析了当前桥梁挠度测量方法中的激光测量法和成像式测量法的原理,讨论了两种方法的优劣,在综合二者优点的基础上提出了一种激光图像挠度测量的新方法。并在实验室构建出整个测量系统,进行了室外和室内的测试。实验结果表明:在测量环境基本维持不变的条件下(如密封的梁体),系统漂移较小,完全可以满足具有密封梁体的大型刚构桥梁的高精度、大量程的挠度测量要求。     

ZNC—1型智能桥梁挠度测试仪

该测试仪能测量桥梁承载时的倾角和挠度,自动绘制和打印出光滑的倾角和挠度曲线.介绍了主要技术指标、系统硬件、软件设计,较为详细探讨数学模型及算法.     

二维激光图像挠度/位移测量系统的结构性误差及解决方案研究

为提高二维激光图像挠度/位移测量系统的测量精度,通过对系统的结构特点及其可能造成误差的原因分析,从结构和设计上对系统进行了包括对称激光器安装、弱衍射激光准直装置和激光靶标的水平安装等方面的改进.通过改进,系统有效地消除了因结构原因造成的不稳定性,显著提高了系统精度.实验证明,改进后的系统精度大大提高并可投入工程中直接使用.     

ROBOTEST激光测量系统

ROBOTEST 激光测量系统是 POLYTEC 公司新近生产的一种非接触式机器人动态、静态精度测试系统。它主要用来测量机器人的位置精度、重复性和可逆性、以及三维平移坐标(直角坐标)和三个旋转方向上的运动精度。同时可以测量上述方向上的运动速度,加速度和过渡过程时间.并能对机器人的机械性能进行测试和记录。图1是六个运动轴(自由度)的定义.     

非接触式激光测量系统平台的搭建与实现

零件三维逆向工程对当今的机械制造业具有重大意义,其中,三维表面数据测量是三维模型重建的前提,即是逆向工程的关键步骤之一.而非接触式激光测量技术是今后逆向工程中三维表面数据获取的发展趋势.基于光学三角法测量原理.本文设计了一种非接触式激光测量系统平台,包括主要硬件的选取、硬件系统搭建和VC 软件系统设计.通过一个凹槽零件的实验测量.得到了零件的形状数据,验证了该测量系统的可行性.     

激光投射式位移传感技术在桥梁挠度检测中的应用研究

激光投射式位移传感技术是精确测量桥梁挠度变化的一种有效方法.在介绍现有各种桥梁挠度测量方法的基础上,分析了激光投射式位移传感技术的基本原理和存在的问题,提出了改进措施.实桥测试结果表明,相对精密水准仪的测量效果,改进后的激光投射式挠度传感器在实际桥梁,尤其是高落差、大跨度桥梁的挠度测量中,具有操作方便、测量速度快、测量精度高等优势.该套传感器已成功应用于渝黔高速公路河耳沟大桥的桥梁远程健康监测中.     

光纤光栅测量微挠度的研究

提出一种基于光纤光栅传感技术的微挠度测量系统。将B ragg光纤光栅粘贴于悬臂梁的自由端,当悬臂梁自由端受力发生微挠度弯曲时,光纤光栅将沿轴向发生形变,通过监测B ragg光纤光栅(FBG)传感器反射波长漂移可以测量出悬臂梁的微挠度变化。通过对系统结构理论分析和实验验证,该装置挠度测量范围为0~51μm,测量灵敏度达到0.05μm,线性拟合度达到0.999 7,非线性误差小于0.1%。     

基于LPC2132桥梁挠度传感器设计与实现

挠度是反映桥梁健康状况的最重要指标。本文介绍的基于ARM CPU LPC2132的光电液位挠度传感器具有成本低,自动性能好、精度高、非接触、能连续在线监测等优点。这里重点介绍它的硬件构成、原理和性能分析。最后以山西高速公路小沟特大桥的安全监测系统为实例来具体介绍本传感器的使用情况。     

用光纤技术及荧光法实时测量海藻浓度及其分布的研究

在阐述浮游植物的荧光性基础上，提出了用光纤技术及荧光法产时测量海藻浓度及其分布的一种有效方法，建立了传感器的数学模型，并分析了测量灵敏度，理论分析和实验结果表明，该测量方法是完全可行的。     

基于CMOS激光位移传感器的板厚测量系统

为了提高板材厚度参数的测量效率和精度,本系统利用CMOS激光位移传感器,通过激光三角法实现板材厚度的测量,并利用MPC08运动控制卡控制交流伺服系统实现激光位移传感器的测量定位,同时计算机对采集数据进行分析处理、显示和存储.实验表明该系统运行稳定可靠,测量效率大幅提高.     

A classifier learning system using a coevolution method for deflection yoke misconvergence pattern classification problem

Deflection yoke (DY) is one of the core components of a cathode ray tube (CRT) in a computer monitor or a television that determines the image quality. Once a DY anomaly is found from beam patterns on a display in the production line of CRTs, the remedy process should be performed through three steps: identifying misconvergence types from the anomalous display pattern, adjusting manufacturing process parameters, and fine tuning. This study focuses on discovering a classifier for the identification of DY misconvergence patterns by applying a coevolutionary classification method. The DY misconvergence classification problems may be decomposed into two subproblems, which are feature selection and classifier adaptation. A coevolutionary classification method is designed by coordinating the two subproblems, whose performances are affected by each other. The proposed method establishes a group of partial sub-regions, defined by regional feature set, and then fits a finite number of classifiers to the data pattern by using a genetic algorithm in every sub-region. A cycle of the cooperation loop is completed by evolving the sub-regions based on the evaluation results of the fitted classifiers located in the corresponding sub-regions. The classifier system has been tested with real-field data acquired from the production line of a computer monitor manufacturer in Korea, showing superior performance to other methods such as k-nearest neighbors, decision trees, and neural networks.     

Modelling and calibration of the laser beam-scanning triangulation measurement system

We present an approach of modelling and calibration of an active laser beam-scanning triangulation measurement system. The system works with the pattern of two-dimensional beam-scanning illumination and one-dimensional slit-scanning detection with a photo-multiplier tube instead of a CCD camera. By modelling the system-fixed coordinate, we describe the formulation of 3D computation and propose a calibration method in terms of LSE using a planar fitting algorithm. As a sensor-dependent solution, the estimation is refined in the domain of sensing variables. Result of calibration of the real system and a brief analysis of systematic errors are given.     

基于图像传感器的皮肤纹理自动测量系统设计

为了客观定量评价皮肤纹理的老化,介绍了一种基于图像传感器的皮肤纹理自动测量系统。首先,利用CMOS图像传感器在光照条件下通过光电转换实现对皮肤图像的采集。然后,借助图像处理技术对采集的图像进行处理。最后,用软件定量计算皮肤表面纹理中的各测量指标（如,皮嵴的平均面积、数量、皮沟的深度等）,并在此基础上通过统计学方法来分析各个测量指标的特点。整个系统集采集、处理与计算于一体,具有低功耗、高稳定、应用性广、操作简单等优点。     

3D part inspection path planning of a laser scanner with control on the uncertainty

This article concerns the measurement process of mechanical parts using laser scanners. From the point of view of industrial applications, the objective is to guarantee the measurement accuracy during the scanning with regard to the geometrical product specifications. The proposed method can be summarized as follows: the first step consists of analyzing the interval of tolerance for the different specifications and to attribute to every geometrical entity a maximal uncertainty of measurement. This uncertainty depends on the angle of incidence between the laser plane and the scanned surface. In the second step, an approach based on the concept of visibility is used from the CAD model of the inspected part to find correct sensor guidance in a metrological point of view. A few position-points from this set are used to define the scanning path. Finally, the measurement can be carried out and the specifications can be controlled after the segmentation of the point clouds. An example illustrates the approach.     

基于连通管原理的桥梁挠度自动测量方法

基于连通管原理,采用RS485通讯技术等手段,给出了一种桥梁挠度自动测量的方法。该方法具有实时、在线、远程、精确等特点,且不受人为因素和环境因素的影响。通过重庆石板坡长江大桥应用该方法测量挠度的案例证明,其测量结果的相对误差小于5％,表明该系统稳定可靠。这种测量方法能用于更多桥梁挠度的自动监测。     

Bounds on evacuation time for deflection routing

Summary Upper bounds are given on the timeT needed to evacuatek packets from a synchronous packet network using deflection routing, whereby all packets that arrive at a node during one time slot leave the node during the next slot. For example,Tn+2(k–1) for a binaryn-cube network when priority is given to packets closer to their destination, and for a single destination networkT is less than or equal to the network diameter plusk–1 times the network deflection index. Deflection routing for one pass through an omega network is also considered. Bruce Hajek received a B.S. in Mathematics and an M.S. in Electrical Engineering from the University of Illinois and a Ph.D. in Electrical Engineering from the University of California at Berkeley. He is a Professor in the Coordinated Science Laboratory and the Department of Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign, where he has been since August, 1979. His research interests include communication and computer network algorithms, information theory, random processes, and combinatorial optimization.Supported by the National Science Foundation under contract NSF ECS 83 52030 with matching funds provided by AT&T. Postal address: CSL, 1101 W. Springfield, Urbana IL 61801, USA.     

A crenellated-target-based calibration method for laser triangulation sensors integration in articulated measurement arms

This work presents a method for integrating laser triangulation sensors (LTS) in articulated arm coordinate measuring machines (AACMM). First, the kinematic parameters of the AACMM are identified using a passive self-centering probe and a multipose optimization algorithm based in point and length constrains. Then, by means of a single calibration gauge object, a one-step calibration method to obtain both intrinsic – laser plane, CCD sensor and camera geometry – and extrinsic parameters related to AACMM main frame has been developed, allowing the integration of LTS and AACMM mathematical models without the need of additional optimization methods after the previous sensor calibration, usually done in a coordinate measuring machine (CMM) before the assembly of the sensor in the arm. Experimental tests for accuracy and repeatability show the suitable performance of this method. The technique presented is easily generalizable for LTSs integration in robot arms and CMMs.