基于环形光投射成像法的管内壁尺寸表貌测量系统

本文首先介绍了基于环形光投射成像法的管内壁尺寸形貌测量的测量原理 ,接着分析了系统结构参数设计的理论依据以及管内壁尺寸的几何关系 ,并讨论了数据处理的方法。试验结果表明原理正确 ,技术可行     

异形热态锻件几何尺寸测量方法的研究

提出一种异形热态锻件几何尺寸测量方法。基于线激光器、CCD和伺服系统构建线激光扫描测量系统,通过提取图像上被锻件表面轮廓调制的激光条纹二维信息,经过坐标变换及点云三维重构得到锻件三维尺寸信息。针对被测异形锻件形貌特征,建立基于摄像机运动的扫描测量模型,并提出一种基于棋盘参考平面的摄像机光心轨迹求解方法。根据平面上特征点在CCD图像不同帧中的坐标拟合摄像机的运动轨迹,结合扫描测量模型实现对异形锻件完整轮廓尺寸的测量。通过实验对封头进行扫描测量,得到球冠部分截面测量直径误差小于4 mm,满足热态锻件测量要求,验证了该方法的可行性。     

管内壁尺寸形貌的非接触检测法

本文以光三角法为基础阐述了两种非接触测量管内壁尺寸形貌的方法：激光单光点回转扫描法及激光环形光切图像法。并给出了此两种方法的适用范围     

新型火炮缠角测量系统设计

提出了一种基于投影法的新型火炮缠角测量系统。该系统主要由照明光源、反射锥镜、CCD相机和驱动机构组成。首先，用光源把身管内壁照亮，然后经过锥镜反射后内壁在CCD相机中成像，最后对该数字图像进行分析，计算得到缠角。本文阐述了测量火炮缠角的计算方法、系统硬件配置及软件设计，最后对该方法的技术特点进行了总结。     

摄像器件(CCD)的构成

拍摄图像的摄像机的基本构成如图 1所示。摄像机由镜头、光学系统、摄像器件、电子电路构成的。景物被照明灯照射 ,摄像机对准景物时 ,通过镜头形成光学影像 ,摄像器件将景物的光学影像变换成电信号。摄像器件只是将光的亮度信息变换成电信号。在彩色摄像机需要的彩色信息情况下 ,还需要有获得彩色信息的光学系统。由摄像器件而来的电信号经过各种图像处理电路以后 ,被送到 VTR的记录部分或被送给传送部分。本文将要介绍目前使用的 CCD类型的工作原理 ,以及获取彩色图像的彩色分光系统。一、CCD的摄像功能及电荷转送的原理摄像器件 CCD…     

高能激光束在线测量系统的光取样器研制

针对环形光刀取样式高能激光光强分布测量系统的要求,研制了以圆弧反射面环形光刀架构的光取样器,实现了对激光束的在线取样测量。光取样器的取样光刀外形设计为环形光刀,可对取样光束进行周向扩展,满足半数以上探测器接收取样空间光信号的要求;取样光刀反射面设计为圆弧形,可对取样光束进行切向扩展,使其在增大衰减倍率的同时降低系统对光的难度。通过光取样器具体设计参数的计算,获得了满足探测单元与反射光束耦合孔径角要求的参数设计范围。实验表明,研制的光取样器可有效用于大面积高能激光束的在线测量。     

单CCD摄像机的一种三维自动测量系统

本文介绍了利用光截面发射器、单CCD摄像机和双定向技术实现物体表面三维自动测量的系统.文中叙述了系统的组成和测量原理,详细介绍了利用控制板的单CCD摄像机双定向技术,将三维问题简化为两次二维求解的解算过程,空间三维坐标的自动解算和实物模型的量测等.系统中使用的直接线性变换(DLT)方法具有形式简单、方便实用、解算稳定可靠的特点,在解算过程中无需相机的内外方位元素.系统所用的方法是单CCD摄像机进行物体表面三维自动测量的新途径.     

四发射单接收光学非接触测头

研究开发了一种具有4个发射光源和1个CCD摄像机作为接收装置的光学非接触测头．测头可以用来测量包括具有强反射表面的曲面．测头基于三角法工作原理．在恰当设计的情况下，至多只有1路从工件表面反射回来的光，能够进入CCD摄像机．通过将相应通道切断，很容易消除镜面反射光的影响．这时测头就相当于1个三发射单接收光学非接触测头．测头可以同时用来测量表面的位置和方向．对于具有很大倾斜的表面具测头仍能正常工作,采用干涉滤光片消除了环境光的影响．提出了一种系统的标定方法．通过对量块的测量证实了系统工作的正确性和有效性并给出了实验结果．     

光电高精度全场形位检测系统的研究

介绍了光电高精度全场形位检测系统，该系统以面阵CCD作为被测物体边缘图象的探测器件，应用激光衍射和图象处理技术进行被测物体边缘的精确定位，实现了高精度全场形位检测，该系统具有测量速度快，检测精度高及数据处理自动化等特点。整个系统是近代光9学，光电技术与微机技术的有机结合。     

三目视觉测头在自由曲面测量中的应用

自由曲面的逆向工程是先进制造技术中的一个关键技术．开发了一种线结构光三目视觉测头，这种包括3个CCD摄像机在内的测量系统具有许多优点，避免了双目视觉中存在的匹配现象．它不但具有高效率、高精度和高可靠性的特点，而且适用于复杂自由曲面的在线测量．针对工作原理以及相关问题，对其进行了详细的讨论，其中包括系统优化、摄像机标定、采样策略、特征提取、图像匹配和数据重构．实验证明三目视觉测头在精度和可靠性方面都优于双目测头．首次研制测头的精度达到了0．02mm．     

基于环形激光的深孔内膛形貌检测系统研究

提出了一种基于环形激光的深孔内膛检测系统,该系统主要由环形激光发生器、反射锥镜、CCD相机以及驱动装置等组成。通过对环形激光器投射在被测身管内膛上的环形光斑进行成像和分析计算,可对身管内膛的一个截面形廓进行检测,并在驱动装置的驱动下,实现对深孔内膛形貌的三维检测。     

Three-dimensional measurement of distant objects based on laser-projected CCD images

A novel measuring system based on a single CCD camera and two laser projectors to record images and perform three-dimensional measurement of a distant object is proposed here. Because of the alignment of the laser beams which form in parallel with the optical axis of the CCD camera, projected spots will appear on the same scan line in a CCD image. As a result processing of a single scan line rather than the whole image is only required to identify the projected spots in the CCD image. Complex computation of video signals of the whole image via either pattern recognition or image analysis methods is therefore circumvented. On the basic of an established relationship between the distance and pixel counts between the projected spots in the CCD image, the proposed system not only measures the distance from a distant object but also the length of two arbitrarily designated points on the object. To provide better accuracy, intrinsic parameters of the CCD camera are taken into consideration in the measurement. Furthermore, the effect of laser diffusion is also proved to be irrelevant to the measuring accuracy here. Experimental results have demonstrated that the proposed measuring method is capable of yielding accurate results of three-dimensional measurement for a distant object in a very responsive way.     

一种药室参数测量新方法

提出了一种新的火炮药室参数测量方法.采用环行激光投影、CCD摄像及数字图像处理的方法测量药室直径;采用圆光栅在药室内壁滚动的方法测量药室长度,根据直径和长度数据求得药室的容积;对各测量参数的精度进行了理论上的分析.结果表明,该方法具有很高的测量精度,能够满足药室参数实际测量的需要.     

三线阵CCD相机亚像元精度几何标定方法研究

为了解决三线阵CCD立体测绘相机内方位元素的几何标定问题,提出了一种实现相机亚像元精度内方位元素和交会角标定的方法。该方法利用光学高精度角度发生器和CCD细分测量相结合的检测方法,由最小二乘回归分析,实现相机内方位元素的标定,并通过扫描星点图像标定交会角。校飞实验的数据处理结果验证了该方法的有效性。     

基于摄影测量的基准尺长度测量系统的调节与误差分析

基准尺作为摄影测量长度基准,其精度直接影响测量结果的准确性,为了保证基准尺长度的测量精度,设计了由气体静压导轨、激光干涉仪、CCD成像系统组成的测量系统。分析了影响测量精度的因素,并对组成基准尺的标志圆成像位置、CCD相机光轴、激光干涉仪、基准尺和CCD成像系统绕自身光轴旋转的调节误差进行了计算分析,用于指导CCD成像系统、激光干涉仪和基准尺的调节。最后应用该系统对基准尺进行多次测量,结果表明基准尺长度测量的标准差可达到1 μm,满足工业摄影测量的要求。     

On-line Nonintrusive Measurement of Particle Size Distribution Through Digital Imaging

This paper presents the further development in the design and implementation of an innovative optical instrumentation system that can measure the size distribution of particles in a pneumatic suspension. A low-cost charge-coupled device (CCD) camera is used to capture the images of the particulate flow field, which is illuminated by a low-cost laser sheet generator. The particle size distribution is then determined by processing the particle images through the use of novel processing algorithms. Experimental results obtained on a small scale particle flow test rig have demonstrated that the system is capable of measuring the size distribution of pneumatically conveyed particles with repeatability better than 1% for a volumetric concentration up to 2%. A relative comparison is made between the on-line imaging technique and the widely accepted laser diffraction based particle sizing method. In addition to laboratory scale testing, results obtained in an industrial setting are presented and compared favorably with off-line reference values     

Digital holographic profilometry of the inner surface of a pipe using a current-induced wavelength change of a laser diode

Phase-shifting digital holography is applied to the measurement of the surface profile of the inner surface of a pipe for the detection of a hole in its wall. For surface contouring of the inner wall, a two-wavelength method involving an injection-current-induced wavelength change of a laser diode is used. To illuminate and obtain information on the inner surface, a cone-shaped mirror is set inside the pipe and moved along in a longitudinal direction. The distribution of a calculated optical path length in an experimental alignment is used to compensate for the distortion due to the misalignment of the mirror in the pipe. Using the proposed method, two pieces of metal sheet pasted on the inner wall of the pipe and a hole in the wall are detected. This shows that the three-dimensional profile of a metal plate on the inner wall of a pipe can be measured using simple image processing.     

Magneto-optic microscope for visually detecting subsurface defects

A visual test method for detecting microdefects under fine surfaces is described. A new MO microscope that has a laser source, a CCD camera, and an exciting coil is developed for this work. A pulse generator supplies an intermittent square pulse to the exciting coil, which can intensify eddy currents yet reduce the working temperature of the exciting coil and sample. The magnetic field variation produced by the imbedded defect causes a rotation of the polarization plane of the reflected beam. Therefore the reflected beam carries an image of the defect, which is received by a CCD camera. The optical arrangement guarantees that no light is reflected back to the laser. The system was tested with a calibrator, which has an artificial subsurface defect; such a test attains a visual detected image. To our knowledge this is the first time an image of a subsurface defect has been distinctly detected with a MO sensor system.