基于机器视觉的大幅面陶瓷地砖尺寸测量研究

Research on Dimension Measurement of Large Size Ceramic Floor Tiles Based on Machine Vision

提出一种基于机器视觉的单相机大幅面陶瓷地砖尺寸高精度测量方法。设计一种由多个反射镜组成反射光路的光学系统。该光学系统采用单个相机采集陶瓷地砖4个角的图像,而不是整幅图像,避免了采用多个相机采集测量图像导致不同步的问题,提高了测量精度。提出一种基于边界搜索拟合和动态补偿的瓷砖测量算法。在该算法中,考虑实际生产中瓷砖的偏移和旋转,利用采集的瓷砖4个角图像,通过对图像进行边界搜索和测量尺寸动态补偿,获取陶瓷地砖高精度的对角线和边长尺寸。设计的系统用于测量600mm×600mm及800mm×800mm瓷砖的对角线和边长尺寸时,其标准差均小于0.02mm,重复性精度接近0.06mm。实验结果表明,该测量系统能够在高档陶瓷地砖生产企业得到广泛的应用。

A dimensional measurement method with high accuracy for large size ceramic floor tiles based on the machine vision using single camera is presented. An optical system is designed, whose reflective light path consists of multiple mirrors. The images of four corners of the ceramic floor tiles are acquired by the single camera rather than the whole image, thus the asynchronous problem caused by multiple cameras acquiring the measured images is solved. Then the accuracy of measurement is improved. An algorithm for the tiles measurement is proposed based on boundary searching fitting and dynamic compensation. In such an algorithm, considering shift and rotation of the tiles in practical production, the dimension of diagonals and sidelines with high accuracy can be obtained by using the images of the four corners, which boundary searching of the measured images and dynamic compensation of measured dimension is performed. The measured standard deviation is less than 0.02 ram, and the repeatability approaches 0.06 mm when measuring dimension of diagonals and sidelines of 600 mmX 600 mm and 800 mmX 800 mm tiles. The experimental results show that the measurement system can be widely used in ceramic floor tiles manufacturers with high quality.