轮对多通道图像采集触发技术研究

车辆轮对磨耗参数的检测,对保证车辆安全运行具有重要作用。针对动态检测图像采集过程中,运动车辆轮对的定位与图像采集问题,研制了适用于轮对在线检测环境的多通道图像采集触发系统。通过对所选择的车辆检测传感器性能研究,对检出信号进行了优化处理,减小了传感器检测环节引入的误差;通过采用多传感器组实现了对不同运行速度轮对进行速度检测并设计了触发控制核心电路板来实现对多路信号的集中处理;控制软件根据检测结果调整相机拍摄时间,捕捉到达设计位置的轮对图像;利用单片机自有定时中断模块设计了较高精度的软、硬件计时功能。实验及研究结果表明,该多通道图像采集触发系统运行稳定,重复性实验中的触发延时误差小于0.001 s,图像采集的效果与精度达到设计要求。     

轮对在线检测中基于异面特征点的摄像机标定

基于光截图像的轮对在线检测中,摄像机的标定技术直接影响轮对参数的检测精度。针对轮对在线检测环境,设计了一套摄像机标定系统。在该系统中,设计特制的平面标定板,将其竖直固定于轨道面不同位置,通过异面特征点实现了摄像机的标定。并利用摄像机标定软件实现了标定板图像采集,图像处理,特征点计算机图像坐标提取和摄像机内外部参数计算。实验结果表明,该标定系统的摄像机标定精度在0.1mm以内,可应用在轮对在线检测中。     

基于HALCON的织物质量检测技术研究

为解决玻璃纤维织物人工检测时效率低、劳动强度大等问题,搭建了基于机器视觉的织物质量在线检测系统。根据视场和测量精度的要求,确定了图像采集模块中的相机、镜头和照明方式,形成了有利于图像处理的成像效果;在基于HALCON的图像处理模块中,提出了采用Blob分析法进行缺陷特征的提取,给出了图像分割、形态学处理和特征提取等过程的关键算子;对一些织物样品图像进行了实例验证。研究结果表明,采用本研究所述检测技术,可以简单、快速地实现织物缺陷特征的识别和缺陷特征参数的计算,检测结果稳健可靠,能够满足实际生产的需要。     

基于图像处理技术的凸轮盘检测方法研究

为满足凸轮盘的在线检测需求,提出了基于图像处理技术的凸轮盘检测方法。首先对凸轮盘图像进行放大、形态学滤波、模糊处理、阈值分割和目标区域提取等预处理,得到凸轮盘二值图像;然后根据内轮廓最小包围矩形进行初调,根据精确直线拟合进行微调,将凸轮盘摆放至合适的角度位置;最后,完成凸轮盘回转中心坐标的求取,对凸轮盘外轮廓点进行采样后与设计值进行对比,并输出检测结果。结果表明:该方法检测效率高、操作简单,能满足凸轮盘在线检测的各项要求。     

FPGA图像处理在带钢表面缺陷视觉检测中的应用

为有效解决冷轧带钢表面缺陷在线视觉检测系统中图像处理的瓶颈问题,本文提出了一种新型冷轧带钢表面缺陷检测与识别算法流程。首先介绍了阀值中值滤波算法及迭代阀值分割算法;接着对这两种算法的计算流程进行了分析;最后采用Xilinx公司的System Generator模块在Simulink中完成缺陷图像的中值滤波变换及迭代阀值分割任务。实验结果表明:Slice Flip Flops使用率28%,4 Input LUTs使用率10%,Occupied Slices使用率34%,FPGA图像处理技术可以解决图像信息实时处理这一关键问题。FPGA图像处理技术基本满足在线检测的稳定可靠、精度高、抗干扰能力强等要求,且能较好的满足实际生产线上的处理速度要求。     

基于Halcon的齿轮缺陷检测系统设计

针对当前齿轮缺陷检测过程中存在的问题,提出了一种基于Halcon软件开发的齿轮缺陷检测系统的设计方案,实现了测量系统中图像采集与显示、图像处理及运行控制等功能。首先控制转盘运行并利用CCD摄像机实时采集齿轮图像;然后进行图像预处理并对图像进行自动阈值化分割,获得齿轮的中心坐标和轮廓信息;最后基于形态学方法分析各个齿的尺寸并从中识别齿轮存在的缺陷。实验表明,该系统具有较高的测量精度和测量效率,能够满足实际生产的需要,为齿轮无损在线测量提供了新的途径。     

基于机器视觉的玻璃瓶在线检测系统研究与开发

玻璃瓶作为酒饮料的主要包装容器,其产品（特别是瓶口）质量直接影响酒的品质与安全.根据透明玻璃瓶在线检测中缺陷信息弱、生产线抖动等特点,研究与开发了一种基于机器视觉的在线检测系统,应用最大熵法实现瓶口图像的分割以及改进的Hough变换算法实现瓶口图像的定位.实际运行表明,系统动态图像采集效果良好,且图像处理算法快速准确,满足当今高速酒饮料灌装在线检测的要求.     

金刚石印压微孔成形原位图像检测技术

基于图像处理的原位检测方法,通过对采集的微孔图像进行滤波降噪、改进最大类间方差(Otsu)阈值分割、特征提取和圆形拟合等处理,快速输出加工微孔的半径尺寸,并通过像素标定结合加工试验来验证系统的准确性。结果表明:本文提出的图像检测方法可以满足金刚石印压成孔的检测要求,能快速准确地检测出微孔孔径尺寸,精度可达1.13μm。     

基于机器视觉的钣金件缺陷在线检测算法

结合图像处理技术,设计了钣金件缺陷在线检测系统,提出了一种基于机器视觉的钣金件缺陷在线检测算法。首先基于几何形状金字塔分层模板匹配算法检测出大部分有缺陷的钣金件,再创新性地结合图像窗口、阈值分割、区域连通、区域面积及长度计算等技术,开发了膨胀窗口区域算法,以此来筛选出满足形状匹配要求但实际为不合格的工件,从而实现了对缺陷钣金件的检测。实验结果表明,该算法响应速度快,正确率高,可达97.7%,满足了实际应用中对准确度和实时性的要求。     

基于置信传播的立体匹配并行算法

考虑在双目立体视觉匹配算法中置信传播算法虽然能获得较好的视差图但匹配速度较慢,本文提出了一种基于置信传播的并行匹配方法.该方法以置信传播为基础,采用并行机制来提高匹配速度.首先,利用最优边缘算法计算图像中的边缘信息;然后,利用边缘信息将整个待匹配视图切割成若干小的区域,使用OpenMP多核优化算法并行对各个小区域进行匹...     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.