Error Compensation for Three-Dimensional Line Laser Scanning Data

In this paper, the problem of compensation of 3D line laser scanning data for improved inspection accuracy is addressed. This problem is important, as a 3D line laser scanner is about one order less accurate than a touch probe. The approach taken is to compensate through error characterisation. In other words, a software compensation is performed, instead of a hardware compensation, which is probably more expensive. To do so, the errors associated with a 3D line laser scanning system are first characterised. With error characterisation, an empirical formula is obtained relating the errors to the influencing factors including the projected angle and the scan depth. This empirical formula is used to compensate for the digitised surface data obtained by the corresponding laser scanning system. The results show that the proposed approach effectively improves inspection accuracy.     

Error compensation method for a gantry robot and a laser-vision sensor-based chassis module measurement system

This paper describes an error compensation method for a 3D laser measurement system based on a gantry robot used for car chassis sub-frame module dimensional inspection. The method is based on a geometrical model that describes possible distortions in gantry robot installation. Implementation of the error compensation model allows a several-fold decrease in gantry robot positioning error.     

Advanced vision systems for computer-integrated manufacture Part II

This paper describes the application of computer vision techniques to solve a variety of industrial problems. Systems for robot guidance, quality assurance and inspection, and strain measurement are described and details of hardware and software components of each application are provided.     

Determination and mapping of measurement and design coordinate systems using computational geometric techniques

Automotive industry is one of the most prospective manufacturing industries in the present world. In order to keep up with the challenges of competitors, the automobile industries are taking necessary steps to satisfy the customers by supplying products of good quality at lower cost. The machine vision inspection systems play an important role in quality control with their accurate dimensional measurement capability. The data obtained from these systems have to be analyzed using appropriate algorithms. In the present work, algorithms based on computational geometric techniques have been developed, to set up the coordinate system for the data obtained from the laser vision system for subframe and lower arm assembly of automobile front chassis module. The concept of a convex hull and a modified Voronoi diagram are utilized for establishing the coordinate system for measurement data. The design coordinate system is determined using the Voronoi diagrams. The measurement and design coordinate systems are mapped using 3D transformations. The results obtained for the sample data are also presented in this paper.     

五轴激光三维数字化测量系统设计

数据测量是逆向工程的关键技术之一,它直接影响到后续数字化模型还原实物样件的速度和精度。本文比较了逆向工程中通过硬件和软件两种方法拼合数据的误差,介绍了激光测量机的原理,并分别从软硬件的角度完成了五轴激光测量系统的设计。     

激光数字化仿形测量与加工系统

简要阐述激光数字化仿型测量与加工系统的基本原理以及在数控加工中心上的实现方法,探讨实现激光数字化仿型测量系统的软硬件条件、部分硬件电路以及集成方式。实践表明,激光数字化仿型测量与加工系统在机械制造领域有着良好的应用前景。     

机械制造业中激光测试技术最新研究进展及展望

介绍了激光视觉三维测量、激光振动测量、激光层析成像技术以及激光无损检测技术。概述了国内外激光测试技术在机械制造业中的研究成果及使用情况，并展望了其应用前景。     

变M法在电机速度高精度测量中的应用

在分析电机速度常规测量方法优缺点的基础上,引入一种新的方法变 Ｍ 法,并以作者设计的电机速度采集系统为例,说明此种方法的硬软件实现。     

窝点接触力自动测试仪数据采集系统的设计

实现了一种用于自动测量弹性臂窝点接触力的新型测试仪.主要介绍了该仪器数据采集系统的硬件和软件设计.其中硬件电路的设计包含了信号调理电路和信号采集电路,前端使用了仪用放大器调理传感器输出的微弱信号,后端使用了AVR单片机完成AD转换和数据串行传输.上位机软件主要负责仪器的运动控制、视觉测量和数据的采集和处理.软件的数据处理部分采用了Matlab6.5与VC6混合编程来实现窝点接触力的求解.     

机器视觉在尺寸在线检测中的应用

机器视觉在制造系统检测与监视领域占有重要的地位。介绍了一种可应用于工业现场的机器视觉坯（工）件尺寸检测原理、系统硬软件和精度分析结果，并介绍了实验验证的结果。     

复杂曲面零件加工精度的原位检测误差补偿方法

为提高复杂曲面零件的数控机床原位检测精度,分析影响接触式检测系统精度的各项因素及其误差补偿方法。对检测系统的主要误差来源如机床几何误差、测头预行程误差和测头半径误差进行分析研究。在对数控机床的几何误差进行分析和建模的基础上,采用激光干涉仪进行三轴数控机床的单项误差测量和补偿;针对测头检测过程中存在的预行程误差,提出基于径向基函数(Radial basis function, RBF)的预行程误差预测方法,获得测头预行程误差分布图,并对检测系统进行实时预行程误差的补偿;提出改进的三角网格模型顶点法矢计算方法,有效进行三维测头的半径补偿。通过实例零件的加工精度原位检测试验及其与三坐标测量机CMM检验结果的比较,验证了原位检测方法的有效性。     

先进制造业中的激光测试与激光加工技术

论述了激光技术在先进制造业中的重要地位及主要特点,对用于制造业的激光测试和激光加工技术的激光视觉三维测量、激光层析成像、激光无损检测技术、激光振动测量、激光快速成型技术、激光焊接技术、激光切割技术、激光打孔技术、激光标记技术、激光热处理技术和激光内腔加工技术等主要技术进行了研究与分析。     

一种新型工业内窥系统的设计与实现

作为NDT技术的分支，内窥技术从创建开始就一直在工业探伤、质量控制、产品评估等领域发挥着重要的作用。针对传统内窥技术所存在的无法定量测量和检测可达性差等缺陷，这里介绍的系统将立体视觉技术、图像处理技术等先进技术与内窥技术相融合，从硬件和软件两方面入手，研制开发出一套新型的基于立体视觉的内窥图像分析系统，实现了图像显示、深度测量和三维重建等创新性的功能。系统对我国自行研制新型内窥技术，提高工业内窥探伤和故障检测的水平，有着积极的推进意义。     

面向特大型齿轮的激光跟踪多站位定位

提出了面向特大型齿轮的激光跟踪多站位定位测量方法以提高特大型齿轮激光跟踪在位测量系统的齿轮定位精度并精确确定测量仪器与被测齿轮位置与姿态的关系。根据激光跟踪仪多站位测量提供的冗余数据优化求解空间两点间共线方程,建立了特大型齿轮激光跟踪多站位测量模型。然后,提出了利用奇异值分解修正多站位测量模型解析矩阵条件数的方法。 实验结果表明,使用多站位测量模型求得的不同站位待测点间距离的标准差的均值为0.008 mm,明显小于直接在不同站位下测量的标准差均值0.024 mm,表明多站位测量模型具有良好精度控制效果。本文的研究提高了齿轮定位时所需测量点的三维测量精度,为特大型齿轮激光跟踪多站位测量系统建立齿轮坐标模型提供了可靠的数据来源。     

空间圆几何参数的非接触高精度测量方法

分析了空间圆透视投影的数学模型 ,并建立了点的空间三坐标立体视觉测量数学模型。提出了一种基于立体视觉的空间圆几何参数的非接触测量方法 ,根据极线约束求出空间圆在双目立体视觉中的对应匹配点 ,后投影到三维空间求出边缘的实际坐标 ,采用基于空间三维圆最优拟合求取空间圆的几何中心的三维空间坐标和圆半径等几何参数。该方法减小了空间圆透视投影形状畸变引起的测量误差 ,提高了基于视觉方法的空间圆几何参数的测量精度     

车辆动态称重系统的补偿算法研究及其软件设计

车辆动态称重系统作为治理超限运输的主要工具,其测量精度一直是主要的研究课题.通过动态称重的实测数据,运用一元线性回归方法,建立以速度作为补偿因子的补偿模型,然后用该补偿模型对动态测量结果进行修正,并进行了相应的软件设计.实际应用表明该补偿算法具有一定的精度和实用价值.     

基于机器视觉的激光线测量系统的构建与应用

简述了激光测量和机器视觉的基本原理,以此为基础构建了一台新型激光线测量机,介绍了该测量系统的硬件、软件和功能构成,并给出了测量实例。     

Computer vision algorithms for measurement and inspection of spur gears

Precision measurement of gears plays a vital role in gear measurement and inspection. The current methods of gear measurement are either time consuming or expensive. In addition, no single measurement method is available and capable of accurately measuring all gear parameters while significantly reducing the measurement time. The aim of this paper is to utilize the computer vision technology to develop a non-contact and rapid measurement system capable of measuring and inspecting most of spur gear parameters with an appropriate accuracy. A vision system has been established and used to capture images for gears to be measured or inspected. A software (named GearVision) has been especially developed in-house using Microsoft Visual C++ to analyze the captured images and to perform the measurement and inspection processes. The introduced vision system has been calibrated for metric units then it was verified by measuring two sample gears and comparing the calculated parameters with the actual values of gear parameters. The maximum differences between the calculated parameters and the design values were ±0.101 mm for a spur gear with 156 mm outside diameter. For small gears, higher accuracy could be obtained and as well as small difference.     

机器视觉在烟草行业的应用

介绍了机器视觉技术的基本原理和组成,结合目前烟草行业常用的小包、务包包装质量检测系统介绍了机器视觉系统的软、硬件构成.提出了采用机器视觉技术进行小包、条包瑕疵剔除技术中的除对率和除全率概念.列举了机器视觉在烟草行业包装质量检测中的典型应用.指出机器视觉技术在烟草质量检测方面的发展方向.     

运用3D数字化模型的轮胎花纹检测

针对轮胎花纹的几何形状,提出基于3D数字化模型的检测方法。利用测量设备REVscan激光扫描仪获取轮胎花纹的表面数据,并利用Geom agic Qualify软件对获得的数据进行检测,检测结果以图文方式直观进行显示。该研究为轮胎花纹的检测提供了方便、快捷的方法。