伪随机阵列和 Harris角测量在视觉检测中的应用

在三维视觉场景重构过程中,一个难题就是场景图像上的坐标点的匹配问题。在工业检测中,通常解决该问题的方法是采用结构光主动视觉技术,如点结构光、线结构光扫描法以及伪随机编码结构光法等。但是要想用一幅图象在三维欧氏空间中重构三维场景,有效的方法是采用伪随机编码结构光照明主动视觉技术。该方法利用编码结构光照明被测场景,利用编码的窗口特性,使场景被测表面每一个特征点都具有唯一的代码而唯一地被辨识。而图像的特征点提取可以采用简单而稳定的Harris角测量。     

周期伪随机信号序列及其在声学测量中的应用

在声学测量中,经常应用各种相关技术.其中,周期伪随机信号序列相关技术是值得在声学测量中推广应用的新技术之一.这种方法采用周期的伪随机信号序列(又称最大长度序列,或M—序列)作为测量中使用的源信号.通过计算源信号与某接收点传声器输出信号之间的互相关函数,来确定该线性系统的脉冲响应.然后,根据脉冲响应,求得该处的平方衰减声压(Sanared decaying sound pressure),由此出发即可求得所需测定的声学量.     

彩色伪随机编码在特征点匹配中的应用研究

为研究基于单幅二维图像不标定欧氏重构三维场景的理论,解决被动视觉系统中难以解决的特征点匹配问题,文章介绍一种有效的采用伪随机编码结构光照明主动视觉技术。利用伪随机序列的窗口特性,使被编码结构光照明的场景表面每一个特征点都具有唯一的代码,可以唯一地被辨识。实验数据和重构结果验证了该编码的可行性和有效性。     

基于光栅编码的三维主动视觉检测

本文介绍了一种基于白光光栅的主动式视觉测量方案 ,一组光栅由光学系统投射至被测曲面 ,获得序列光栅编码的特征测量图形 ,再利用外极约束条件获得匹配曲线上的空间匹配点 ,进而获得空间点的三维坐标     

基于IHS空间的灰度图像互补色伪彩色编码

对灰度图像的任一灰度级，将对应的彩色影射到垂直于I＝0．5的平面上（I为强度），饱和度S可取的最大值为原始图像最大灰度值的0．75倍，相邻两灰度级对应的H值（H为色度）互为反相。将所得IHS值变换为RGB值即得伪彩色图像。用该方法对医学磁共振图像进行了处理，给出了实验结果。     

彩色伪随机编码图像角点检测方法研究

研究了基于投射彩色伪随机编码图像的三维测量技术中图像特征角点的检测问题.为了克服传统的Harris算子只能对灰度图像进行像素级定位的缺点,提出利用伪随机编码图像独特的窗口阵列唯一特性,将其扩展到彩色图像,并通过对特征点周围的像素灰度值分布做二次曲面拟合并求解其极值,实现了彩色角点的亚像素级准确定位.理论分析和实验结果均表明该方法是有效的.     

激光光斑能量分布的三维伪彩色可视化方法

人眼对不同灰度级的分辨能力非常有限,但对色彩却相当敏感,能区分有不同亮度、色度和饱和度的成千上万种颜色。根据人眼视觉的这个特点,提出了一种激光光斑能量分布的三维伪彩色可视化方法。该方法利用伪彩色技术将激光光斑的256级灰度图像变换为连续变化的伪彩色图像,通过空间灰度插值运算将离散的图像数据生成光斑的彩色三维模型,实现激光光斑能量分布结构的三维可视化,以反映光斑不同区域能量分布的相对大小和位置,并可以通过3D坐标变换进一步方便人们从各个角度观察激光的能量分布。这为光束质量的评判提供了重要依据。     

机器视觉在包装检测过程中的应用研究

从机器视觉的角度出发，提出了一种基于机器视觉的包装检测方案。详细论述了实时图像处理的过程，并采用简单、快速、有效的算法对实时图像进行处理，得到较好的效果，并满足了实时的要求。     

角检测在彩色伪随机编码图像特征提取中的应用

为研究基于单幅二维图像不标定欧氏重构三维场景的理论,有效提取伪随机编码图像特征角点,介绍了一种角检测方法,该角检测方法是基于轮廓线曲率的测试,实验数据和重构结果验证了该检测方法的适用性和有效性。     

视觉检测技术及应用

视觉检测技术,尤其是基于三角法的主动和被动视觉检测技术具有非接触、速度快、柔性好等特点,是一种先进的检测手段,适合现代制造业的需要。文章论述了视觉检测技术原理,讨论了已经研制的多个实际视觉检测系统,从不同角度展示了视觉检测技术在现代制造业中广阔的应用前景。     

Theoretical issues in the design of visual inspection systems

The objective of this review essay is to both chronicle and analyse literature in the area of visual inspection. Classical as well as contemporary papers are included to describe both the historical development and the state of the art of visual inspection theories and technologies. Human operators, despite well-documented problems, often perform visual inspection. While supervized machine systems obviate some of the problems associated with human inspectors, other problems still exist. In particular, accounting for a supervisor's perception of a machine's performance (as gauged, e.g. by trust) and consequent actions. The difficulties associated with these two alternatives have led to the emergence of a third alternative: collaborative human/machine or hybrid systems, which combine the advantages of both alternatives—in theory. However, in practice, how to best distribute the functions between a human and machine, in a dynamic environment in real time, is problematic. Moreover, a human's perceptions of its counterpart's performance remain an issue. These unresolved problems are subjects for future research. In the interim, the alternatives are critiqued to create a basis for establishing guidelines to select the alternative that is best suited for a given situation.     

Mission planning optimization for the visual inspection of multiple geosynchronous satellites

In this article, a new manoeuvring strategy for the multiple geosynchronous satellites inspection problem is proposed. In contrast to previous research, it can be used to visit multiple geosynchronous satellites orbiting in different orbital planes in an economical way. In the proposed mission scenario, several chasers are initially placed in an equatorial high eccentric orbit. Two orbital manoeuvres are exerted at perigee to adjust the apogee of the chaser for every inspection. Subsequently, the targets will be visited when they fly through the ascending or descending nodes of their orbits. Based on the proposed strategy, a two-level optimization approach is developed to optimize visitation order and time regarding fuel consumption. Meanwhile, the manoeuvre velocity and time are determined. Finally, the proposed method is applied to several numerical test cases to demonstrate its validity for mission planning optimization for the visual inspection of multiple geosynchronous satellites.     

数字化检测在MES中的应用研究

讨论了机械制造企业中三维数字化检测的相关技术,进行了基于DMIS标准的数字化测量研究.通过三维检测技术与生产车间制造执行系统(MES)的结合,完成了基于三维轻量化模型的检验工艺管理、检验任务的执行与管理、产品质量数据和状态的可视化管理,以及产品的质量审理和追溯.这些研究实现了机械制造企业检验的自动化和无纸化,达到了对检...     

A review of the science and art of visual examination in failure analysis

Visual examination is usually the first step in a failure analysis, but it is not a subject about which much has been written. In this paper, techniques of visual examination and documentation using digital photography are discussed. The use of different types of lighting to reveal characteristics of manufactured and fracture surfaces is explored. Practical examples of lighting setups and photographs obtained using these setups are presented.     

目标方位连续性在拖线阵左右舷分辨中的应用

为了解决传统拖线阵存在的左右舷模糊问题,已经发展了双线阵和三元组集束的线列阵。这两种结构的线列阵在通常情况下都可以较好地完成使命,但在实际应用中还可能会遇到一些困难。对同时存在多个目标且舷角值比较接近时影响其左右舷分辨结果的几种情况做了分析,提出了利用多目标运动的方位连续性修正其左、右舷分辨结果的新技术,提高了上述两种结构线列阵左右舷分辨结果的准确性和抗干扰能力。仿真结果验证了新方法的有效性,并对三元组线列阵海上实验数据进行处理,结果验证了新方法的稳健性,可望应用于工程实践中。     

Propagation of elastic waves in honeycomb panels for application to rapid inspection techniques

This paper considers the properties of elastic waves guided by an aluminum plate bonded to a honeycomb core for application to rapid inspection of honeycomb panels. Current acoustic inspection techniques involve the transmission of a signal between a pair of small transducers located on opposite sides of the panel. Scanning the transducers in raster fashion results in a high resolution inspection of the panel, but is very time consuming. An alternative technique would simultaneously inspect all points along a line between two widely spaced transducers located on the same side of the panel. Scanning the pair once over the panel permits rapid inspection, although with decreased resolution. Studies presented here indicate that such a method of inspection is feasible and that the flexural mode is probably the most useful.     

矢量拖曳式线列阵声呐流噪声影响初探

研究矢量拖曳式线列阵声呐护套管内的流噪声场。根据湍流边界层脉动压力谱的Corcos模型,采用频率-波数域上的二维谱方法,分析了流噪声对矢量拖曳式线列阵声呐的影响。给出了护套管内流噪声场声压和质点声振速的一般表达式,并由波数积分法得到护套管内点接收器、有限几何尺寸水听器和水听器阵列输出的流噪声各分量的功率谱。数值结果表明,矢量拖曳式线列阵声呐对流噪声的轴向分量十分敏感,在流噪声控制背景下,矢量阵的工作性能将退化为常规阵。     

大型活动票、证实名制查验系统设计及应用

通过对国家大型活动票、证实名制查验系统的需求分析,提出将成熟的物理、数字防伪技术及先进的查验技术引入大型活动票、证管理平台,设计开发电子票、证实名制查验系统,并成功应用于南京青奥会开闭幕式。     

目标跟踪在拖线阵左右舷分辨中的应用研究

针对常规拖线阵声呐存在的左右舷模糊问题,提出了一种将平台机动与目标跟踪相结合的拖线阵左右舷分辨方法,利用镜像产生左右舷目标对,根据真实的跟踪目标及其镜像目标的速度差来自动判决目标左右舷.通过仿真分析,对于10 km距离以上的目标,不管位于左舷还是右舷,平台通过小角度转向5°,经过2个扫描周期,真实的跟踪目标与其镜像目标...