厚度测量中对射激光束共线性视觉检测  

Vision detection for laser beam collinearity in thickness measurement

作　　者：李加福 朱小平[2] 杜华[2] 唐文彦[3] LI Jia-fu;ZHU Xiao-ping;DU Hua;TANG Wen-yan(National Institute of Metrology, Beijing 100029, China;Scholl of Electrical Engineering and Automation, Harbin Institude of Technology, Harbin 150001, China)

机构地区：[1]中国计量科学研究院长度所,北京100029 [2]中国计量科学研究院,北京100029 [3]哈尔滨工业大学电气及自动化学院,黑龙江哈尔滨150001

出　　处：《光学精密工程》2020年第8期1690-1699,共10页Optics and Precision Engineering

基　　金：国家重大科学仪器设备开发项目(No.YQKFB1803-1);质量技术监督能力提升专项(No.ANL1822)。

摘　　要：针对厚度测量中对射激光束共线性的要求,提出了一种基于双分光棱镜的传感器光轴空间位姿视觉检测方法。在分光镜坐标系下,分析了单条激光束在组合分光棱镜中的光线传播和光斑变化规律,建立了两条激光相对位姿与光斑中心点之间的数学模型。借助于棱镜坐标系和图像坐标系之间的转换关系,可以根据四个拟合光斑中心坐标快速计算出激光束的相对位姿,进而将激光束的共线测量转换为光斑中心坐标的拟合、对比问题。实验结果表明,在传感器测量范围内,该方法可以使两条激光束之间的夹角不大于0.17°,距离不大于0.05 mm;同时,调整前后对量块的测量表明,厚度测量误差由12μm减小到4μm,间接验证了共线检测方法的有效性。所提方法实现了光束调整过程的数字化、可视化,并且使共线性测量结果具有可溯源性,有助于定量分析因两个激光传感器测量线不重合而引起的厚度测量误差。To meet the requirement of the collinearity of laser beams during thickness measurements,a vision detection method for sensor optical axis position is proposed based on a double-splitting prism.According to the light propagation path and spot variation rules of a single laser beam in two spectroscopic prisms,the mathematical model between the relative positions of the two lasers and the spot centers is constructed according to the spectroscope coordinate system.With the help of the conversion relationship between the prism coordinate system and image coordinate system,the relative positions of the laser beams can be quickly calculated using the four fitting spot center coordinates,which can convert the collinearity measurement of the laser beam into the fitting and provides a comparison of spot center coordinates.The experimental results show that using the proposed method,the maximumangle between the two laser beams is 0.17°,and the maximum distance is 0.05 mm in the measuring range.Under these conditions,the measurement of the gauge block before and after adjustment shows that the thickness measurement error is reduced from 12μm to 4μm,which indirectly verifies the effectiveness of the collinear detection method.The proposed method realizes digitalization and visualization in the laser beam adjustment process,enables metrological traceability of the measurement results,and helps to quantitatively analyze the thickness measurement errors caused by the non-coincidence of the measuring lines of the two laser sensors.

关 键 词：共线检测 激光光轴 厚度测量 激光位移传感器 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]