应用数字散斑投影测量纸页厚度

传统的纸张厚度测量方法只能测量纸页某一点厚度, 该类方法会因为纸张厚度全场分布不匀带来测量误差。针对该问题, 提出利用数字散斑投影的纸页厚度检测方法, 向待测纸页投射散斑图案, 并构建散斑投影的实验测量系统, 通过三维数字图像相关的算法处理, 得到纸页的形貌以及厚度。实验表明, 对纸张厚度名义值为0.180 mm的实验样品进行测量, 结果为0.177 mm, 对该方法进行重复实验, 测得的相对误差小于4%, 而且该方法能够直观地显示纸页的全场分布。此外, 提出的纸页厚度测量方法具有结构简单、非接触式测量、全场测量等优点, 为纸页生产中的厚度检测提供了新思路。

Apply of digital speckle projection in measurement of paper sheet thickness

Traditional measurement methods of paper sheet thickness can only measure the thickness of paper sheet at a certain single point, leading to the measurement error due to the uneven distribution of the paper sheet thickness. A new approach of paper sheet thickness measurement using digital speckle projection was proposed to address the problem of single-point measurement. The thickness and contour of paper sheet could be determined by executing the three-dimensional digital image correlation algorithm, after the speckle pattern was projected to the tested paper sheet and a speckle projection experimental system was built. The experimental result is 0.177 mm for measuring the paper which nominal value of thickness is 0.180 mm, and the repetitive experimental results show that the relative difference is less than 4%. Moreover, the full-field distribution of the paper sheet thickness is shown intuitively. In addition, the proposed method of paper sheet thickness measurement has the advantages of simple structure, non-contact full-field measurement, etc., which make the proposed means a promising approach for the measurement of paper sheet thickness during the paper production.