【作者】 王悦；

【导师】 刘东； 项震；

【作者基本信息】 浙江大学 ， 工程硕士（专业学位）， 2020， 硕士

【摘要】 惯性约束聚变(Inertial confinementfusion,ICF)系统中存在大量不同口径的光学元件,这些元件承受三倍频激光通量,最容易发生激光损伤,导致激光系统的输出能力受限。而光学元件是否会发生激光损伤与元件的亚表面缺陷息息相关,在本文所研制的光学元件亚表面缺陷检测系统中,需要进行精密的调平与对焦工作,这部分工作如果完全依赖于人工,费时费力。待检测光学元件口径不断变大,数量不断增多,对缺陷检测系统的自动化、智能化提出了更高的要求。因此,有必要开展针对本文所研制的光学元件亚表面缺陷检测系统的自动调平与对焦研究。本文的主要内容如下:介绍了本文所研制的光学元件亚表面缺陷检测系统的检测原理与光路结构,搭建了基于现有缺陷检测系统的调平、对焦硬件系统,编写了实现调平、对焦自动化的软件模块。在自动调平方面,结合手动调平的方法与原理,提出了基于激光位移传感器的三点测距自动调平算法。根据被测样品口径的不同,设计不同的调平方案。将大口径光学元件调平时长从人工的四十分钟缩短到机器自动化的一分钟以内。在自动对焦方面,介绍了现有的多种自动对焦技术。根据本文所研制的缺陷检测系统中光学元件特有的成像特点,比较了多种清晰度评价函数以及搜索算法的优缺点,提出了基于此缺陷检测系统的自动对焦算法。将光学元件对焦从肉眼对焦转化为机器对焦,对焦效率与对焦精度均得到大幅度提升。最后,通过实验验证了自动调平方案的可行性与有效性,找到了最适合本文所研制的缺陷检测系统的清晰度评价函数,验证了自动对焦方案的可行性。自动调平、自动对焦系统的建立,极大程度地提高了本文所研制的光学元件亚表面缺陷检测系统的检测效率,提高了检测系统扫描拼接后图像的清晰度,使得成像效果以及缺陷检测的准确性也得到了相应的提升。更多还原

【Abstract】 A huge quantity of large-aperture optical components are present in inertial confinement fusion(ICF)system.These components withstand triple-frequency laser flux are prone to laser-induced damage,which limits the output capacity of the laser system.The laser-induced damage of optical components is closely related to the subsurface defects of the components.In the subsurface defects detection system of optical components,precise leveling and focusing work are required.,which is labor intensive and time consuming.With the growth of aperture and quantity of optical components,there is a higher demand of an automated and intelligent defects detection system.Therefore,it is necessary to carry out a research on automatic leveling and focusing of subsurface defects detection of optical components.The content is as following:We introduce the principle of the detection system of subsurface defects of optical components,build the hardware for leveling and focusing based on the current detection system,and design the software module to realize automatic leveling and focusing.Regarding auto-leveling,based on the principle and method of manual leveling,we propose an automated approach utilizing trilateration and laser displacement sensors.Different leveling processes are designed for different apertures of the components.The leveling time of large-aperture components is reduced from forty minutes to less than one minute thanks to the automatic solution.In terms of auto-focusing,we introduce some existing techniques,compare several sharpness evaluation functions and searching algorithms based on the unique imaging characteristics of defects detection system,and propose an auto-focusing method for this system.The manual focusing on large-aperture components is replaced by auto-focusing with machine.The focusing time and accuracy is improved dramatically.Lastly,the proposed auto-leveling scheme is proved to be feasible and effective through experiments,the sharpness evaluation function most suitable for the defect detection system is found,and the feasibility of the auto-focusing scheme is verified.The automatic leveling and focusing system has greatly increased the efficiency of the defects detection system,enhanced the image sharpness after scanning and splicing,and improved the accuracy of imaging and defects detection.更多还原