激光双路对称透射法在线测量平板玻璃厚度

Method for on-line measuring thickness of glass by using laser two-way symmetrical transmission way

针对传统测量平板玻璃厚度的不足,基于光的折射原理,提出一种双路激光对称透射法,设计了在线测量平板玻璃厚度的装置,以线激光做光源,以对称平面镜组为光路转换装置,将对称分布的光路调制为两束相互平行的线激光,线阵CCD传感器作为视觉探测工具,并针对测量图像的特点,选定背景与目标的过渡区域段的灰度值,作为单束线光带图像的边界阈值,使用改进灰度重心法提取线光带中心像素。通过对待测样品的实验检测,结果表明该方法测量精确可达0.1mm,该精度符合玻璃生产线中对其厚度检测标准的要求。由此证明了该方法的可行性,并具有良好的实用价值。

For the shortcomings of the traditional flat glass thickness measurement, one method which was based on the principle of light refraction, with the dual laser symmetrical transmission method was proposed, and the whole measured system of on-line measurement of flat glass thickness was designed, in which line laser was the light source and the symmetry plane of mirrors were the optical path switching device to modulate the symmetrically distributed optical paths into two parallel line lasers, and a linear array CCD sensor was set as a visual exploration tool, meanwhile, the grey level of the transition area of the background and target was selected as the boundary threshold value of the single beam line’s light band image according to the characteristics of captured image, the algorithm for obtaining light band center pixel was made modified gray gravity. After the experiment of the measurement on the sample glass thickness, the results show that the accuracy of these measurement methods can reach to 0.1 mm. The measuring accuracy is correspond with the requirements of the testing standards. Therefore the feasibility is verified, that have a good practical value.