【作者】 谭奇良；

【导师】 周肇飞；

【作者基本信息】 四川大学 ， 测试计量技术及仪器， 2004， 硕士

【摘要】 大尺寸测量在重型工业中占有重要地位，许多大型零部件的生产和装配过程都需要使用大尺寸测量，例如船舶的建造，飞机机翼的装配等。随着科学技术的进步，一些高科技产业，特别是航空、航天工业，对大尺寸测量精度要求越来越高。然而，长期以来大尺寸测量一直是测量领域的薄弱环节；虽然光电技术的引入在一定程度上提高了测量效率，但是其测量精度不高一直是困扰技术人员的难题。如何提高大尺寸测量的精度成了一个亟需解决的问题。 经过长期的研究，发现大气扰动是影响大尺寸光电测量精度的主要因素之一。如何减小和消除大气扰动的影响成为进一步发展大尺寸光电测量技术的关键。本课题(属国家自然科学基金项目)将自适应光学技术引入大尺寸测量领域，研究了一种适用于大尺寸光电测量装置中的波前修正系统(自适应光学系统)，利用该系统可以减小和消除大气扰动对大尺寸测量的影响，提高测量精度。 这种自适应光学系统建立在解卷积式自适应光学原理的基础上，结合了波前探测技术和解卷积图像复原技术。在结构上，该系统主要分为三个组成部分：成像系统、波前传感器和数字图像处理系统。高速CCD器件和光学镜头组成了成像系统，用来采集原始图像；波前传感器用来探测光波波前畸变，系统中采用的是自适应光学中常用的哈特曼—夏克波前传感器；数字图像处理用来进行解卷积图像复原运算，它包括计算机硬件和软件两部分。其工作原理如下：首先，系统采用哈特曼一夏克波前传感器对测量激光束进行探测，测量光束受到空气扰动，其畸变会反映到波前传感器探测到的波前信息上。通过对波前信息进行波前重构等一系列处理最终得到系统的瞬时光学传递函数。最后，通过对瞬时传递函数和原始图像进行解卷积图像复原运算，可将原始图像上的畸变复原。 在点光源和扩展光源的条件下，分别对本自适应光学系统进行实验，其结果表明本系统对大气扰动后的目标图像有较好的复原效果。 与传统自适应光学系统(校正式自适应光学系统)相比较，这种解卷积式自适应光学系统省去了波前校正环节，以软件替代了价格昂贵的倾斜镜、变形镜和复杂的控制电路。因此，它具有体积小、结构简单，制造成本低廉等优点，适合广泛应用于大尺寸测量系统中。 本文首先分析了光波在大气中的传输理论和大气成像的数学模型，从理论上论证了解卷积式自适应光学的工作原理，然后介绍了本系统的硬件和软件设计，最后介绍了实验结果，并且对实验结果作了分析。关键词:大尺寸光电测量自适应光学波前传感器解卷积图像复原更多还原

【Abstract】 The measurement of large-scale is very important to heavy industry. It is necessitated in the process of manufacturing and assembling large size workpiece, such as ship building, aerofoil assembling etc. With the development of technology, the high precision measurement of large-scale is needed by high-tech industry, especially in aerial and space industry. However the large-scale measurement is the weak point of measurement technology. Though the photoelectricity technology has improved the efficiency of large-scale measurement; the problem of low precision still puzzles the technologist. Nowadays how to improve the precision of large-scale measurement is a crucial task.Constant study indicates that atmosphere turbulence is one of the primary factors that affect the precision of measurement in photoelectricity large-scale measurement instrument. So how to eliminate the affect of atmosphere turbulence is the key to improve the large-scale measurement precision.In order to eliminate the atmosphere turbulence, Adaptive Optics technology is introduced to photoelectricity large-scale measurement, and a new Wavefront Correction System (Adaptive Optics system), which is applied to large-scale measurement instrument, is developed.This Adaptive Optics system is based on deconvolution Adaptive Optics theory, which has used the wavefront detecting and image deconvolution restoration technology. The Adaptive Optics system is constituted of three parts, which are an image device, a wavefront sensor and a digital image processing system. The imagedevice is used to capture the image, which is composed of a high-speed CCD and a camera lens. The wavefront sensor is used to detect the light wavefront aberrance, and a Hartmann-Shack wavefront sensor is adopted in this system. The digital image processing system is used to process the wavefront data and image, which is composed of computer software and hardware. The work principle of The Adaptive Optics system is as follows: first, The Hartmann-Shack wavefront sensor detects light wavefront, and if the light-wave is disturbed by atmosphere turbulence, the wavefront error will react on the wavefront data, which is detected by Hartmann-Shack wavefront sensor. After wavefront reconstruction and some other operation, the Optical Transfer Function can be obtained. At last, the aberration of the image will be corrected through processing of image deconvolution from wavefront detecting.The experiments with point sources and extended sources are performed respectively. The results show that the Adaptive Optics system can be used to restore the image that is disturbed by atmosphere efficientlyCompared with traditional Adaptive Optics system, the deconvolution Adaptive Optics system has the advantages of lower costs and simpler construction, because software is used to substitute the expensive optic components and controller. So the Adaptive Optics system is suitable for the large-scale measurement instrumentIn this paper, the mathematic model of light-wave transfers and image in atmosphere is analyzed firstly, and the theory of deconvolution Adaptive Optics is demonstrated then, whereafter the design of hardware and software of the system is introduced, the experiment and result are presented and analyzed at last.更多还原