基于差动共焦的倾角测量传感器  

Tilt sensor based on differential confocal microscope

作　　者：王廷煜 王之一 杨永强[1,2] 糜小涛 王建立[1,2,3] 姚凯男 程雪[4,5] WANG Ting-yu;WANG Zhi-yi;YANG Yong-qiang;MI Xiao-tao;WANG Jian-li;YAO Kai-nan;CHENG Xue(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Science,Beijing 100049,China;Jilin Provincial Key Laboratory of Intelligent Wavefront Sensing and Control,Changchun 130033,China;Suzhou Institude of Biomedical Engineering and Technology,Chinese Academy of Sciences,Suzhou 215163,China;Jinan Guoke Medical Technology Development Co.,Ltd.,Jinan 250102,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049 [3]吉林省智能波前传感与控制重点实验室,吉林长春130033 [4]中国科学院苏州生物医学工程技术研究所,江苏苏州215163 [5]济南国科医工科技发展有限公司,山东济南250102

出　　处：《液晶与显示》2023年第11期1481-1489,共9页Chinese Journal of Liquid Crystals and Displays

基　　金：国家自然科学基金(No.62005273,No.12133009);山东省自然科学基金青年基金(No.ZR2020QF100)。

摘　　要：为了解决传统激光差动共焦显微镜(LDCM)无法在测距的同时,进行高精度倾斜角度测量的问题,提出了一种基于差动共焦的倾角测量传感器。在对倾斜表面进行测量时,该传感器首先利用轴向扫描获取的差动响应信号精准定位其焦点位置,然后分析显微镜光瞳面场强分布并提取光斑图像的峰值位置,从而实现对倾角的精准测量。首先,建立聚焦光束经倾斜待测面反射后的光场分布模型,对不同倾斜角度下显微镜光瞳面的场强分布情况进行分析。然后,在分析倾斜光斑特征的基础上,提出了采用改进Meanshift算法进行光斑峰值位置提取的方法。最后,通过实验验证了传感器对倾角测量的有效性。实验结果表明,传感器对倾斜程度(0~8°)测量平均误差为0.011°,对倾斜方向(0~360°)的测量平均误差为0.128°,能够满足利用差动共焦非接触光学探针对三维表面进行检测的过程中,对待测表面倾斜角度测量的要求。该传感器为自由曲面的高精度轮廓测量提供了一种新的方法。In order to solve the problem that traditional laser differential confocal microscope(LDCM)can not measure the angle of tilt with high precision while measuring the distance,a kind of angle measurement sensor based on LDCM was proposed.When measuring the inclined surface,the sensor first uses the differential response signal obtained by axial scanning to accurately locate the focal position,and then analyzes the pupil field intensity distribution of the microscope and extracts the peak position of the spot image,so as to achieve the accurate measurement of the inclination.First,the field distribution model of the focused beam reflected by the tilted surface to be measured was established,and the field intensity distribution in the pupil plane of the microscope was analyzed at different tilt angles.Then,on the basis of analyzing the characteristics of slanting spot,a method of extracting the peak position of spot using improved Meanshift algorithm is proposed.Finally,the effectiveness of the sensor for tilt angle measurement is verified by experiments.The experimental results show that the average error of the sensor is 0.011°for the tilt degree(0°~8°)and 0.128°for the tilt direction(0°~360°),which can meet the requirements of measuring tilt angle of measuring surface in the process of detecting three-dimensional surface by using LDCM.The sensor provides a new method for high precision contour measurement of free-form surface.

关 键 词：非接触光学探针 差动共焦 三维检测 倾斜测量 峰值提取 

分 类 号：TH741[机械工程—光学工程]