共查询到20条相似文献,搜索用时 218 毫秒
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针对现有点衍射三维坐标测量系统中的坐标高精度解调问题,提出了一种基于Levenbery-Marquardt(LM)算法的点衍射干涉测量方法。基于L-M算法的点衍射测量技术是以点衍射干涉理论为基础,在实现干涉场相位分布信息解调的基础上运用基于L-M算法的二重迭代算法重构出点衍射源的三维坐标。为验证所提出测量方法的可行性,同时进行了计算机仿真和测量实验,并与三坐标测量机的测量结果进行了对比。结果表明:该测量方法可在xyz三维方向上100mm×100mm×300mm空间范围内实现优于微米量级的测量精度。该测量方法具有不依赖算法迭代初值、测量精度高、运算速度快、抗噪声能力强等诸多优点,在三维坐标测量及测量系统的校准中具有较好的实用性。 相似文献
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单摄像机虚拟立体视觉测量技术研究 总被引:6,自引:0,他引:6
以双目立体视觉传感器三维测量模型为基础,提出了一种用于测量空间三维点坐标的低成本单摄像机模型。该模型利用光学成像,把单摄像机镜像为一对虚拟摄像机,在一个CCD像面上采集到同一物体存在视差的两幅图像,从而恢复空间点的三维信息。讨论了单摄像机传感器测量空间三维点坐标的基本原理,建立了单摄像机传感器的测量模型,克服了双摄像机系统中成本高、切换采集左右摄像机的图像使检测速度减慢等诸多缺陷,为空间三维点的精密测量提供了经济、快速、有效的测量途径。实验表明.传感器可实现约0.8%的相对测量精度.证明了本方案合理、有效。 相似文献
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针对大型物体三维形貌视觉测量,提出了一种新的视觉测量三维数据拼接方法。以一台高分辨率数码相机作为全局测量设备,在测量过程中固定不动,并以数码相机坐标系作为全局坐标系。视觉传感器流动到不同位置对物体各子区域进行测量,获得局部坐标系下的三维数据。以一平面靶标为中介将视觉传感器在各位置的局部坐标系统一到全局坐标系下,从而将三维数据统一到全局坐标系下,完成三维拼接。该方法无需在被测物上贴标记,因此适用于任何材质的被测物,且消除了拼接累积误差。实验结果表明,该方法相对拼接误差为0.076%。以Venus石膏像为被测对象,视觉传感器对其三个局部区域进行测量,给出了局部测量结果及拼接结果。 相似文献
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基于光学测棒的立体视觉坐标测量系统的研究 总被引:7,自引:2,他引:5
提出了一种基丁测量与校准功能合一的光学测棒的立体视觉坐标测最系统.采用光学测棒作为成像目标,通过任意放置的两台摄像机获取测棒上的发光特征点的图像实现被测物体三维坐标的测量,同时利用测量数据定期对两台摄像机外部方位参数进行校准.深入研究了两台摄像机内部参数和外部方位参数校准过程中的校准件和校准算法的设计,以及系统测量建模等关键技术,提出了相应的解决方案,减小了摄像机内外参数校准及测量模型对测量结果的影响,提高系统的测量精度.实验结果表明.该系统的最大测量误差为0.11 mm. 相似文献
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相移正交物体运动方向的在线相位测量轮廓术 总被引:3,自引:0,他引:3
提出了一种新型的基于相位测量轮廓术(PMP)的在线三维检测方法.只需要使投射的条纹相移方向与物体移动方向垂直,尽管由于物体运动使CCD采集变形条纹中物体坐标不一致,但通过像素匹配,可以使各帧图像物点坐标一一对应,得到与传统静态PMP等效的相移条纹图,即可重构出物体,实现在线三维测量.对一实平面进行了在线与静态PMP测试对比实验.结果显示该在线PMP方法与传统静态PMP方法的均方差之差仅为0.007mm,表明该在线PMP方法具有高精度性;对一实物进行了在线测试实验,很好地重构出了被测物体的三维轮廓,从而验证了该方法的可行性和有效性. 相似文献
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Shape measurement is a significant application of digital image correlation (DIC). An improved method that combines a rotatable plane mirror is proposed to measure the shape of an immovable object. In this method, two images, one before and the other after rotating the plane mirror, are obtained and then in-plane translation which related to the shape of the detected object can be calculated by the use of two-dimensional digital image correlation (2D DIC). The relationship between the in-plane translation and the shape of the object is described. Experimental results show that the proposed method is feasible for shape and distance measurement with high accuracy. 相似文献
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Shih-Heng TungMing-Hsiang Shih 《Optics and Lasers in Engineering》2011,49(7):937-945
The traditional three-dimensional (3D) digital image measurement technique uses at least two images captured from different positions to determine the 3D coordinate of an object. One disadvantage of this method is that the mechanical and optical properties of the image capture devices are not fully identical, and the calibration procedure is quite complicated. This paper introduces a simplified 3D digital image correlation (DIC) method, in which only one image capture device is used. The theoretical measurement error equation is derived and experimentally verified. Experimental results show that distortion correction plays an important role in the improvement of measurement precision. After a radial distortion correction, the measurement precision of the object distance can reach 0.0043%. The optimal camera spacing should be set from 1/50 to 1/30 of the object distance, to obtain a satisfactory precision. 相似文献
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《中国光学快报(英文版)》2016,(1)
Because the bottom of the cavity has the shadow and occlusion, the angle between the projection system and imaging system is limited. So the traditional fringe projection technique based on the principle of optical triangulation is inapplicable. This Letter presents a 3D shape measurement method of using the light tube for the cavity. The method can measure an object from two opposite views at the same time, which means it will obtain two different groups of 3D data for the same object in a single measurement. The experimental results show the feasibility and validity of the 3D shape measurement method. 相似文献
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A monocular method to measure the pose of a translation-only one-dimensional (1D) object containing at least two known characteristic points is presented. The position of any other point on the 1D object can be located after the pose measurement. Scene information is not needed to apply the method. If the distance between the characteristic points is unknown, there is a scale factor between the object's real positions and the measurement results. The method can also be used to measure the pose and shape parameters of a parallelogram, prism or cylinder object. 相似文献
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A three-dimensional (3D) resolution measure for the conventional optical microscope is introduced which overcomes the drawbacks of the classical 3D (axial) resolution limit. Formulated within the context of a parameter estimation problem and based on the Cramer-Rao lower bound, this 3D resolution measure indicates the accuracy with which a given distance between two objects in 3D space can be determined from the acquired image. It predicts that, given enough photons from the objects of interest, arbitrarily small distances of separation can be estimated with prespecified accuracy. Using simulated images of point source pairs, we show that the maximum likelihood estimator is capable of attaining the accuracy predicted by the resolution measure. We also demonstrate how different factors, such as extraneous noise sources and the spatial orientation of the imaged object pair, can affect the accuracy with which a given distance of separation can be determined. 相似文献
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A new 3D shape measurement method based on non-integral twin-frequency grating projection is proposed. In this paper, the projected composite grating is composed of two sinusoidal gratings, and the quotient of whose frequencies is not an integer. By using appropriate phase-shifting algorithms, two wrapped phases can be obtained from sixteen frames of the distorted grating patterns. In aid of appropriate phase unwrapping method, the unwrapped phase of high frequency fringe is obtained only from the relation of the two wrapped phases by a pixel-to-pixel phase unwrapping technique. Therefore the unwrapped phase of high frequency fringe pattern is independent of the low frequency fringe pattern, different from traditional integral twin-frequency grating projection methods in which the phase unwrapping error of low frequency fringe pattern may be propagated onto the unwrapped phase of high frequency fringe pattern. The new theory proves that the proposed method is applicable to measure discontinuous object, and has considerable measurement accuracy. 相似文献