共查询到19条相似文献,搜索用时 156 毫秒
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《光学学报》2017,(4)
针对大型结构表面积较大而像机视野有限的问题,提出了一种基于传递像机的移动摄像测量方法,该方法可对大型结构进行全局扫描测量。利用固定连接于移动平台的传递像机对基准标识点进行图像采集,采用像机参数标定方法对传递像机的外参数进行计算,得到相邻时刻移动平台坐标的相对转换关系。测量像机在移动平台的驱动下围绕结构表面采集特征点,利用运动平台坐标的转换关系计算得到测量像机的实时外参数。建立等效双目交会共线方程,并对特征点位置进行计算,在初始位置完成参数标定后,即可实现自动测量。实验结果表明,所提出的移动摄像测量方法的测量精度可达2.012mm,且自动化程度较高,可应用于大型结构的在线监测。 相似文献
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一、引言 测量弹丸飞行姿态,特别是出炮口100—200m以内的飞行姿态,是外弹道测试的重要内容。它与弹丸的飞行稳定性及射出密集度的研究有着非常密切的关系。 弹丸摆动幅值(攻角)及摆动波长的大小因弹而异,通常攻角幅值约2°~15°,波长约几米到几十米。要求至少可能测量3~5个摆动波长的攻角变化曲线。 相似文献
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针对目前微观三维表面形貌测量技术中存在检测效率和测量范围较小的问题,提出一种基于双线阵相机的线扫描差动共聚焦三维形貌测量方法。采用线扫描光源,利用线扫描拼接算法,分别合成焦前和焦后图像;再利用差动算法获得样本位于测量区域的差动图像,结合预先刻度的轴向响应曲线,完成样本的三维形貌还原,实现大范围高效测量。实验结果证明:基于双线阵相机的线扫描差动共聚焦三维形貌测量方法在相同时间内测量范围和测量效率分别是白光干涉仪的16.48倍和6.59倍,并且该方法在测量过程中不需要停顿,只需实现一次对焦,就可以对样品进行连续不间断的扫描检测。研究成果为满足智能制造中在线在位、实时高效、大范围测量的检测需求提供依据。 相似文献
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某型机载武器飞行试验中,由于测试用摄像机安装位置的特殊性,导致摄像机视场交会区域较小,无法采用常规影像交会测量的方法获取武器投放过程的轨迹、姿态运动参数,针对该问题,设计了一套适用于近距离、大倾角条件下的机载武器投放试验影像测试方案。通过设计90°和120°弯折光路的特殊弯管镜头,转换摄像机安装位置,解决武器投放影像获取问题,通过建立大倾角多摄像机联合计算模型,实现了武器投放轨迹、姿态的测量。实验室仿真实验结果表明,采用该方案轨迹最大测量误差不大于2 cm,满足飞行试验精度要求。 相似文献
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针对飞行弹丸对空中目标近炸炸点位置测量,提出了多幕光学法测量技术。根据试验特点,分析了多光幕交汇测量弹丸炸点位置存在的问题,研究了采用侧向相机辅助多光幕交汇测量技术。通过相机采集到的炸点图像,建立相机、模拟目标和多光幕交汇光幕阵列空间几何计算模型。利用弹丸的飞行轨迹和弹丸炸点图像平面坐标,研究了弹丸炸点侧向空间坐标的计算方法和多光幕交汇测量系统二维坐标修正原理,给出了弹丸炸点坐标计算函数。利用微分法从交汇光幕夹角、光幕幕厚、测时和测距等方面分析测量误差。经计算分析,模拟目标中心高度小于50m时,炸点三维坐标的误差小于40mm。 相似文献
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Camera calibration plays an important role in the field of machine vision applications. During the process of camera calibration, nonlinear optimization technique is crucial to obtain the best performance of camera parameters. Currently, the existing optimization method aims at minimizing the distance error between the detected image point and the calculated back-projected image point, based on 2D image pixels coordinate. However, the vision measurement process is conducted in 3D space while the optimization method generally adopted is carried out in 2D image plane. Moreover, the error criterion with respect to optimization and measurement is different. In other words, the equal pixel distance error in 2D image plane leads to diverse 3D metric distance error at different position before the camera. All the reasons mentioned above will cause accuracy decrease for 3D vision measurement. To solve the problem, a novel optimization method of camera parameters used for vision measurement is proposed. The presented method is devoted to minimizing the metric distance error between the calculated point and the real point in 3D measurement coordinate system. Comparatively, the initial camera parameters acquired through linear calibration are optimized through two different methods: one is the conventional method and the other is the novel method presented by this paper. Also, the calibration accuracy and measurement accuracy of the parameters obtained by the two methods are thoroughly analyzed and the choice of a suitable accuracy evaluation method is discussed. Simulative and real experiments to estimate the performance of the proposed method on test data are reported, and the results show that the proposed 3D optimization method is quite efficient to improve measurement accuracy compared with traditional method. It can meet the practical requirement of high precision in 3D vision metrology engineering. 相似文献
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为了测量弹丸水面落点的位置, 建立了基于CCD相机动态像面的测量模型。该模型通过CCD相机辅助采集相关点位的图像信息, 对水面落点的位置函数以及误差进行了研究。首先, 利用空间几何获得靶船上三定点相对于测量船的方位、俯仰信息。接着, 结合t时刻观测图像上定点的像面坐标, 运用底片常数模型建立像面坐标和角度信息两套参量之间的关系函数, 从而得到目标落点的方位、俯仰信息, 再利用异面交会法计算出目标落点位置。最后, 分析了目标落点位置的误差来源(质心误差, 位置误差)、误差以及各误差源与位置坐标之间的关系。实验结果表明:在测量船位置精度达到0.05 m, 图像质心定位精度达到0.5 pixel时, 在最小交会误差的情况下, 目标落点的位置测量误差分别为2.8, 4.9, 4.3 m。 相似文献
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针对现有的提高线阵电荷耦合器件(CCD)成像系统的图像空间分辨率的方法存在的不足,提出了一种新的采样模式,并设计了一种高分辨率成像系统。该系统利用两个相同的线阵CCD相机进行特定的空间排列,即使得相机1和相机2的CCD阵列都倾斜θ来进行扫描取像,并利用图像校正和像素插值等图像重建方法,得到高分辨率的图像。实验结果表明,倾斜角取60°的情况下,相对于单个线阵相机在θ=0°的正常采样模式下得到的采样图像,图像的空间分辨率提高了1倍,且保持了成像的视野不变。本系统工程上实现简单,十分经济且便于维护,仅利用现有的成像装置即可获取更高分辨率的图像。 相似文献
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利用TDI CCD成像数值仿真模型,研究了TDI CCD测量系统的测角精度随扫描镜速度稳定度的变化规律。首先根据TDI CCD推扫成像的物理过程,建立了数值仿真模型,设计了从光学像和扫描镜稳定度到数字图像的仿真链路;然后利用图像重心计算方法求取图像中心坐标并得到目标点的角位置坐标;通过蒙特卡诺法进行海量打靶试验,对结果进行统计得到扫描镜各稳定度水平上的测量精度值;最后将某工程样机的扫描镜速度稳定度带入仿真模型,仿真结果表明:测试误差增大5.67 μrad,达到了像元角分辨率的1/4。在光学测量系统的系统设计时,需要考虑像元分辨率及扫描镜稳定度的综合影响,选用合适的扫描镜稳定度要求,使测量角分辨率满足用户需求。 相似文献
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An image encryption method with two-step-only quadrature phase-shifting digital holography, based on the calculated intensity of reference wave is proposed. Compared with the presented image encryption method based on phase-shifting technique, the technique need only to record two quadrature-phase holograms on CCD camera, without reference-wave intensity or object-wave intensity measurement, and the encryption keys to perform image encryption on Mach-Zehnder interferometer. When the reference-wave intensity is acquired from 2D correlation coefficient method our presented, the clear retrieved image can be obtained at high speed by certain algorithm. Its feasibility and validity were verified by a series of computer simulations. 相似文献
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In shooting range, projectile burst location is an important indicator. To solve the question that multi-screens across measure method cannot gain projectile proximity fuze burst location parameters when projectile close to simulation object at high altitude, the method of lateral camera assistant multi-screens across was proposed to amend the coordinates of four screens across system and realize projectile proximity fuze burst three-dimensional coordinates. The principle and existed question of four screens across system in measuring projectile burst coordinate were analyzed, and according to their measure shortcomings, the calculation model of lateral camera assistant four screens across system was set up, its amendment arithmetic was educed and analyzed, at last, the amendment three-dimensional coordinates of projectile burst location was give out based on their space geometry relation, and the measure errors were analyzed. Through experiment, the amendment measure projectile proximity fuze burst three-dimensional coordinates arithmetic was validated, and the results show the amendments measurement method is scientific and feasible. 相似文献