用于三角测量大数值孔径双远心光学系统设计  

Optical design of bi-telecentric system with large numerical aperture for the triangulation measurement

作　　者：赵哲承 朱嘉诚 刘雪峰[5] 宋玲玲 陈新华 沈为民[1,2,3] ZHAO Zhecheng;ZHU Jiacheng;LIU Xuefeng;SONG Lingling;CHEN Xinhua;SHEN Weimin(School of Optoelectronic Science and Engineering,Soochow University,Suzhou 215006,China;Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province,Suzhou 215006,China;Key Lab of Modern Optical Technologies of Education Ministry of China,Suzhou 215006,China;Suzhou PLS Technology Co.,LTD.,Suzhou 215008,China;Unit 63801 of the PLA,Xichang 615000,China)

机构地区：[1]苏州大学光电科学与工程学院,江苏苏州215006 [2]江苏省先进光学制造技术重点实验室,江苏苏州215006 [3]教育部现代光学技术重点实验室,江苏苏州215006 [4]苏州普立视科技有限公司,江苏苏州215008 [5]中国人民解放军63801部队,四川西昌615000

出　　处：《红外与激光工程》2024年第7期188-195,共8页Infrared and Laser Engineering

基　　金：江苏高校优势学科建设工程(PAPD);苏州市产业前瞻与关键核心技术项目(SYC2022142)。

摘　　要：测量不确定度是与测量结果紧密相关的重要指标,反映了仪器测量的稳定性。激光三角测量仪器的测量不确定度与成像光学系统数值孔径直接相关,增大数值孔径能够有效降低测量不确定度。为了满足高精度测量需求,应用二维Q-type多项式自由曲面,设计用于线激光三角测量仪的大数值孔径双远心Scheimpflug成像光学系统。首先基于三角测量原理和线激光三角测量仪指标分析成像光学系统参数,然后结合像差灵敏度分析以及自由曲面像差特性,确定成像光学系统中自由曲面的位置和数量并进行优化设计。设计得到系统的数值孔径为0.2,成像范围为10 mm×14 mm,调制传递函数(MTF)优于0.6,最大畸变为0.21%,远心度优于0.3°。该系统具有大孔径、成像质量好、畸变小、双远心的特点,能够满足高精度线激光三角测量仪的应用需求。Objective With the development of technology and the requirement of industrial manufacturing, the automatic measurement of key dimensions of products in the production process has gradually replaced the traditional manual measurement. As a non-contact measuring instrument, line laser triangulation instrument has the advantages of simple structure, small size and wide application. However, the uncertainty of measurement for this instrument is physically limited by the speckle, which are formed when the measured surface is illuminated by the laser. Fortunately, this uncertainty can be improved by reducing the laser wavelength or increasing the numerical aperture of the optical system. Lasers with a short wavelength of 405 nm are already widely used in triangulation instruments, and increasing the numerical aperture of the optical system is another one method to further reduce the measurement uncertainty. However, the further increase of numerical aperture brings great difficulties to the design of optical systems while keeping the field of view unchanged.Methods To improve the measurement uncertainty of the line laser triangulation measurement instrument, this paper designs a bi-telecentric system with large numerical aperture with the two-dimensional Q-type polynomial freeform surface. Firstly, the working principle of the triangulation measurement instrument is introduced. Based on the principle and the specifications of the line laser triangulation measurement instrument, the parameters of the imaging optical system are analyzed. Then, the optical system based on double-Gauss optical layout is designed and the optical stop is placed on the focal plane of front group and back group. The position and number of freeform surfaces in the imaging optical system are determined by using the aberration sensitivity analysis and the freeform surface aberration characteristics. Finally, the optical system is optimized with optical design software to achieve the best performance.Results and Discussions Two-dimensional Q-type

关 键 词：线激光三角测量仪 光学设计 双远心光学系统 二维Q-type自由曲面 

分 类 号：O436[机械工程—光学工程]