State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Sensors (Basel). 2018 Nov 11;18(11):3882. doi: 10.3390/s18113882.
Three-dimensional (3D) measurement of microstructures has become increasingly important, and many microscopic measurement methods have been developed. For the dimension in several millimeters together with the accuracy at sub-pixel or sub-micron level, there is almost no effective measurement method now. Here we present a method combining the microscopic stereo measurement with the digital speckle projection. A microscopy experimental setup mainly composed of two telecentric cameras and an industrial projection module is established and a telecentric binocular stereo reconstruction procedure is carried out. The measurement accuracy has firstly been verified by performing 3D measurements of grid arrays at different locations and cylinder arrays with different height differences. Then two Mitutoyo step masters have been used for further verification. The experimental results show that the proposed method can obtain 3D information of the microstructure with a sub-pixel and even sub-micron measuring accuracy in millimeter scale.
三维（3D）微结构测量变得越来越重要，已经开发出许多微观测量方法。对于几毫米的尺寸以及亚像素或亚微米级的精度，目前几乎没有有效的测量方法。在这里，我们提出了一种将微观立体测量与数字散斑投影相结合的方法。建立了一个主要由两个远心相机和一个工业投影模块组成的显微镜实验装置，并进行了远心双目立体重建过程。通过对不同位置的网格阵列和不同高度差的圆柱阵列进行 3D 测量，首先验证了测量精度。然后，使用两个 Mitutoyo 台阶标准器进行了进一步验证。实验结果表明，该方法可以在毫米范围内以亚像素甚至亚微米的测量精度获得微结构的 3D 信息。
