Novel coordinate mapping algorithm for three-dimensional profile noncontact measurement
Novel coordinate mapping algorithm for three-dimensional profile noncontact measurement
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DOI：
10.1117/1.1483087
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发表时间：
2002-07
影响因子：
1.3
通讯作者：
K. Lin;Ming Chang;T. Chen
中科院分区：
文献类型：
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作者：
K. Lin;Ming Chang;T. Chen
一种用于 3D 坐标非接触式测量的测量算法和校准方法的新颖方法已经开发出来。该算法引入了将输出数字图像直接与所观看的 3D 对象相关联的变量。使用最小二乘技术实现了简单而有效的校准过程。它利用 2-D 坐标映射关系，以及双 CCD 相机和由一系列现实空间中已知坐标的特征点组成的 3-D 校准网格。将这些特征点的空间坐标与其在 CCD 中的图像坐标进行比较。然后构建实际空间与其在双 CCD 相机中的图像平面之间的 3-D 映射函数。相应地确定两者之间的关系，并可用于以令人满意的精度从特定空间中的测试对象中提取 3D 信息。该算法不仅显着减少了3D测量计算量，而且提高了测量精度和速度。目前的实验结果表明，在80 x 60 x 60 mm的有界空间内，测量标准偏差低于0.06 mm。这一结果表明，该测量算法有潜力成为快速、精确的非接触式坐标测量系统的有效定位方法。
A novel approach to a measuring algorithm and calibration method for 3-D coordinate noncontact measurement has been developed. This algorithm introduces variables that relate the output digital image directly to the viewed 3-D object. A simple and efficient calibration procedure is achieved using the least-squares technique. It takes advantage of a 2-D coordinate mapping relation, along with dual CCD cameras and a 3-D calibration grid consisting of a series of characteristic points with known coordinates in real space. The space coordinates of these characteristic points are compared to their image coordinates in the CCDs. A 3-D mapping function between the actual space and its image planes in the dual CCD cameras is then constructed. The relationship between the two is determined accordingly and can be applied to extract 3-D information from a tested object sitting in a specific space with satisfactory accuracy. This algorithm not only significantly reduces the 3-D measurement computations, but also increases the measurement precision and speed. Current experimental results show that the measurement standard deviation is under 0.06 mm in a bounded space of 80 x60x60 mm. This result reveals that this measurement algorithm has the potential to be an effective positioning method for rapid and precise noncontact coordinate measuring systems.