Automatic measurement of frontal area and volume of fluted ingots using image-based instrumentation

The development of an image-based measurement system for area and volume estimation is reported here with a novel idea of area projection with partial information. The measurement system has been put into a field trial in one of the Integrated Steel Plants in India. The estimated error was limited to ±0.5% with a high degree of repeatability.     

A novel shape-based coding-decoding technique for an industrial visual inspection system

This paper describes a unique single camera-based dimension storage method for image-based measurement. The system has been designed and implemented in one of the integrated steel plants of India. The purpose of the system is to encode the frontal cross-sectional area of an ingot. The encoded data will be stored in a database to facilitate the future manufacturing diagnostic process. The compression efficiency and reconstruction error of the lossy encoding technique have been reported and found to be quite encouraging.     

反射式光纤位移传感器在测量牙齿咀嚼过程中的应用

反射式光纤位移传感器具有对测量环境的要求低、适用于各种常规方法无法满足的特殊场合、测量范围大和测量精度高等优点.本文简述了该传感器的工作原理,针对牙齿咀嚼过程测量和在口腔中工作的特殊要求设计了专门的光纤头和反射面,建立了一套测量该过程的装置,对该测量系统进行了校准,对牙齿咀嚼过程进行了实时测量,得到了一组人体牙齿咀嚼状况下的实时位移的测量结果,在牙医界第一次实现了牙齿咀嚼过程的动态实时测量.文中讨论了口腔这一特殊的测量环境和一些影响测量精度的因素,在实测中摸索了一些减小误差的方法,最后对测量误差作了分析.     

基于I2C总线的作业面积测量系统的研究设计

当前机械产品在农业作业中得到广泛应用,但缺少一种作业面积测量系统.为此,研制了一种结构简单、操作方便、性能可靠的智能面积测量系统.     

基于HP VEE的超声波塑料焊接温度场检测系统

由于超声波塑料焊接具有升温速度快、局部生热、压力作用的特点使其温度场测量非常困难.文中采用基于HP VEE的温度场测量系统来测量超声波塑料焊接的温度场;并介绍了HP VEE的功能、该温度场测量系统的组成和采用该系统进行的超声波焊接PVC塑料的温度场检测试验.试验表明该系统能够高精度、快速、自动的检测超声波塑料焊接温度场.     

Accuracy assessment of vehicles surface area measurement by means of statistical methods

This paper presents an assessment of the different methods and techniques for measuring a vehicle’s surface area, including a close-range photogrammetric system with calibrated digital cameras, a mid-range laser scanning system and an expeditious method based on a specific tape measurement. These methods are compared with respect to their task-specific accuracy related to the area measurement by means of statistical test for the detection of the significant results. An uncertainty evaluation of these techniques is performed using a standard device that was previously calibrated with a coordinate measuring machine. The assessment of the gathered data reveals a potential for reducing the time and cost associated with close-range photogrammetry for vehicle surface area measurement and digitisation.     

基于三维精密位移工作台的显微图像拼接测量系统

设计了一种大面积无缝无特征显微图像拼接测量系统,该系统基于光学显微系统和大行程纳米级计量型三维精密位移工作台,建立了以测量系统自身的计量系统来标定CCD摄像机和计算CCD与水平工作台夹角的数学模型,解决了一般图像测量系统需借助外部设备进行标定和夹角测量的问题。构建了非正交水平工作台移动策略,用于光学显微图像大面积无缝无特征拼接,减小了拼接量,扩大了横向测量范围,解决了测量视场与横向测量分辨率受限于物镜数值孔径的问题。     

Weighted approach for multivariate analysis of variance in measurement system analysis

In a process that is integral to a measurement system, some variation is likely to occur. Measurement system analysis is an important area of study that is able to determine the amount of variation. In evaluating a measurement system's variation, the most adequate technique, once an instrument is calibrated, is gauge repeatability and reproducibility (GR&R). For evaluating multivariate measurement systems, however, discussion has been scarce. Some researchers have applied multivariate analysis of variance to estimate the evaluation indexes; here the geometric mean is used as an agglutination strategy for the eigenvalues extracted from variance–covariance matrices. This approach, however, has some weaknesses. This paper thus proposes new multivariate indexes based on four weighted approaches. Statistical analysis of empirical and data from the literature indicates that the most effective weighting strategy in multivariate GR&R studies is based on an explanation of the percentages of the eigenvalues extracted from a measurement system’ matrix.     

一种小型高效节水喷灌系统的设计

为提高喷灌系统的节水效果,在深入分析土壤湿度对植物生长影响的基础上,提出了一种小型高效节水喷灌系统的设计.利用土壤湿度实时检测来控制阀门开度,以实现节水的目标.在讨论了可行性、设计价值及控制方法的基础上完成了系统的软硬件设计.系统能够适用于花园、草坪等小范围区域的灌溉,也可应用于温室喷灌.     

轴承保持架计算机视觉检测方法研究

根据铁路轴承保持架的检测要求,研究了基于图像边缘信息的保持架窗孔梁计算机视觉检测方法。根据检测对象的特点,确定了最佳的保持架边缘检测算法。在算法的具体实现过程中,提出了弦长法确定保持架边缘大端外圆圆心、区域划分检测窗孔梁宽度边缘直线等计算方法,实验表明,将计算机视觉引入轴承保持架生产的在线检测成本低、效率高,检测精度满足要求。     

光电跟踪系统鲁棒自调整内模控制设计与分析

光电跟踪系统广泛应用于制导武器、航空航天观测设备以及靶场光电测量仪器等领域。针对光电成像测量时滞和模型不确定性,设计了一种鲁棒自调整内模控制算法。给出基于相位裕度和幅值裕度指标的系统控制器整定方程,分析得到了模型失配情况下的系统鲁棒稳定条件以及参数的设计准则,引入基于二次型性能指标的优化方法在线自适应调整控制滤波器参数来提高系统的控制性能和鲁棒性。在光电跟踪转台上的实验结果表明,所设计算法可有效地克服光电图像跟踪器测量时滞所造成的跟踪偏差,跟踪精度小于1密位,保证了成像传感器对目标的快速准确跟踪。     

一种针对圆形设计容差的二元测量系统能力评价的新方法

在一些测量过程中,测量仪器测得的数据是二维的,且设计容差为一个圆,当二元被测质量特性具有相关性时,无法直接利用常用的一元测量系统能力评价指数对圆形设计容差的二元测量系统进行分析和评价。提出了一种基于面积之比构造评价指数的方法,利用测量误差椭圆面积与设计容差圆面积之比和测量误差与测量值的椭圆面积之比建立测量系统能力评价指数,将常见的一元测量系统能力指数延伸到二元测量系统中,通过多元方差分析(MANOVA)估计评价指数来评价二元测量系统的能力。通过实例对该方法进行了验证。     

Extending the dynamic range of fibre length and fibre aspect ratios by automated image analysis

An automatic image analysis system has been developed, that is capable of scanning a large sample area (70 mm × 70 mm) using transmitted light microscopy. The analysis, based on transparent algorithms, successfully discriminates between overlapping and touching fibres, so that sample preparation time is minimized. The system utilizes overlapping image frames to reconstruct partial fibre images and impart unique fibre length information in the range micrometres to millimetres. The software has been made adaptable to enable the accurate measurement of fibre lengths for fibres that curve over many millimetres. Data are presented illustrating the accurate measurement of fibre lengths over a large range of fibre aspect ratios.     

Customer-focused and product-line-based manufacturing performance measurement

Until the 1980s, manufacturing companies relied solely on performance measurement systems based on traditional cost accounting systems to control, monitor, and improve operations. However, it has been shown that these systems do not capture the relevant performance issues for today’s manufacturing environment. Pre-80s systems focused on monitoring and controlling instead of supporting process improvements, promoting overall system optimization and addressing the dynamics of changing systems. A variety of integrated systems were proposed to overcome the limitations of the traditional performance measurements systems. However, these systems have not yet fully addressed the performance measurement system requirements for today’s manufacturing environment. This paper presents an integrated dynamic performance measurement system (IDPMS) developed in conjunction with the D Company Plant of Chungli, Taiwan. IDPMS integrates three main areas; company management, process improvement, and the factory shop floor. To achieve an integrated system, these three areas are linked through specifications, reporting and dynamic defined success area updating, performance measures, and performance standards. This study is undertaken to specify the interaction and movement among the three groups in the process from production planning to customer, “planning-manufacturing-customer”. The results from these stages, production planning, manufacturing, and customer service, are integrated. These factors are transformed into measurable, quantitative, and JIT (just-in-time) parameters utilized along with management by objectives (MBO) principles in planning and establishing a manufacturing performance measurement system focused on satisfying both internal and external customers. An example is given that illustrates how the IDPMS addresses the current performance measurement system requirements.     

视觉瞄准激光干涉测量编码型水准尺

针对编码型水准尺分划误差的检测,提出了采用视觉瞄准与双频激光干涉测量相结合的方法。构建了编码型水准尺的精密检测系统并对瞄准测量方法进行了研究。当被测条码边缘出现在瞄准视场中,不必微调载尺工作台,即可实现图像和干涉仪测量数据快速采集,并由软件完成瞄准及测量。针对条码边缘图像的检测,首先采用最大方差法分割图像;然后提出图像边缘跟踪法,直接寻找检测边缘,从而避开去除噪声的困难;最后应用概率细分方法对条码边缘定位,提高测量分辨率。经实际测试,该检测系统视觉瞄准标准差为0.23μm,系统稳定性标准差小于0.5μm。该瞄准测量方法提高了测量效率,测量精度高于检测要求4倍,保证了编码型水准尺检测的可靠性。该检测系统已成功应用于编码型水准尺的分划误差检测。     

基于立体视觉的大尺寸工业测量系统

针对工业制造领域普遍存在的大型物体全尺寸测量难题,提出并实现了一种基于立体视觉技术的便携式工业测量系统。该系统采用多个CCD视觉传感器,获取被测物体的多视图像序列,通过前方交会由二维像点坐标计算物体表面点的三维坐标。全局关键点测量由多目立体视觉系统完成,使用CCD相机从多个位置和方向拍摄物体,获得多目视差照片,由测量软件二维处理并完成三维重建。局部区域密集点云的测量由双目立体觉系统完成,左右两相机同步拍摄由投影机投向物体表面的编码条纹,测量软件自动进行立体匹配和三维重建后获得物体表面局部的密集点云。最后测量软件根据局部的关键点完成密集点云的坐标系转换。实验表明,该系统的测量精度达到0.1mm/3m,可以满足工业现场大尺寸测量对精度和效率的要求。     

激光干涉测量中条纹计数的CPLD设计及实现

使用CPLD设计并实现了采用干涉条纹进行测量的光学测量系统中的计数电路部分,取代了传统的多元件分立的电路设计,达到了很好的效果,满足了光学干涉测量准确快速测量的要求。此分析适用于一般条纹计数系统。     

Integration of close range photogrammetry and expert system capabilities in order to design and implement optical image based measurement systems for intelligent diagnosing disease

In medical applications and disease diagnosis devices, image is considered as a tool for measurement and data acquisition. Most of the imaging methods usually used in medical applications are invasive and have several side effects on human body. So, other types of image based measurement systems should be developed for medical applications. The systems must be able to use the images captured in visible part of the electromagnetic spectrum. In this research a new image based disease diagnosis method has been developed which uses optical images for measuring required symptoms. In the systems which are implanted based on the suggested method measurement capabilities of close range photogrammetry and decision making ability of expert system are integrated. The integrated system can be used for the diseases whose symptoms are visible or appear as deformations out of body and around the affected area. For evaluation of the suggested method, an integrated system has been designed and implemented for intelligent diagnosing foot deformity.     

基于线阵CCD的空间目标外姿态测量系统

设计了9路线阵CCD相机组合的空间目标外姿态测量系统,它克服了采用面阵图像传感器用于姿态测量时存在的速度和精度的矛盾。该系统分别实时重构放置于被测物体上的点合作目标在世界坐标系下的三维坐标,经空间解算,确定被测物体的姿态角。着眼于合作目标和相机光学系统的相对位置及呼应,解决了多相机与多点合作目标一一对应时的目标干扰问题;设计了新的光学系统构架,提高了精度,节省了空间;实现了多相机测量系统的局部标定和全局标定。测试结果表明,该姿态测量系统可以实现对被测对象高精度、实时的测量,且具有合作目标简单,价格低廉等优点。     

Evaluation of the coefficient of friction of rail in the field and laboratory using several devices

ABSTRACT

Accurate friction measurement is vital to apply appropriate friction management techniques to the wheel/rail interface. This work analyses different friction measurement techniques under a variety of conditions in the laboratory and the field. Tests have been carried out using a pendulum tester, hand-push tribometer, twin-disc machine and full-scale rig in the UK and Colombia for a variety of interfacial conditions and rail hardness. The pendulum has been found to be more sensitive to different conditions than the hand-push tribometer. This is due to the area that the pendulum sweeps being smaller, and so it can be more carefully controlled and therefore measure the surface condition being tested. This is in contrast to the push tribometer which needs a long section of rail to take a measurement. Twin-disc and full-scale rig creep curves show good agreement between each other.