【作者】 牛建军；

【导师】 刘上乾；

【作者基本信息】 西安电子科技大学 ， 物理电子学， 2007， 博士

【摘要】 火炮静态参数测量是现代火炮研究、设计和使用中的一个必须而重要的技术环节,随着火炮研制、生产水平和使用要求的不断提高,原来基于光学望远系统的人工测量、人工处理数据的测量方法已经不能满足需要,必须建立高精度、高效率、高度自动化的测量系统。本文对我们所研制的、以激光准直与CCD成像测量为核心的、火炮身管弯曲度和药室容积等静态参数测量系统中的光电成像和图像处理等关键技术进行了深入研究。在对现役的火炮身管弯曲度和药室参数的测量原理、测量方法、测量装备的性能及其局限性进行深入研究的基础上,我们设计并实现了一种以激光准直与CCD成像为核心的身管弯曲度和药室参数测量系统方案,本文就系统中特殊环境下的光电图像获取和高精度图像测量两个方面的内容进行了深入重点研究,即针对火炮身管内膛的特殊环境,研究设计了光电成像场景状态控制和近距离高清晰成像的光学系统方案,根据所获取的特殊图像,研究出了相应的图像预处理、图像校正和高精度图像测量方案和算法。在进行了原理实验研究、计算机仿真优化的基础上,该方案和算法已经应用于火炮静态参数测量系统的工程研制,达到了预期效果。本文研究的具体内容主要有：一、光电图像获取方面1.针对火炮身管内膛结构复杂、表面光洁、反射光路极为复杂,用常规技术难以成像的特殊成像环境,利用模拟成像和图像处理技术,研究出了在该特殊环境下实现清晰成像所必须的照度分布条件和相应的照明环境,并采用分布式冷光源,通过光线的散射、折射、相互叠加和补偿等光学技术,形成了CCD相机摄取高质量图像所需的照度分布环境,而且只要适当调整光源配置参数,还可形成适应不同炮管内膛环境所需的最佳成像的照明环境。2.在图像信息获取中,通过对测量系统在物距短、视场角大的特殊要求下的光电成像的深入研究,分析了这种特殊要求下影响成像质量的主要因素和技术难题,即光学系统景深的限制导致的光图清晰度的非均匀分布,通过数学建模、优化方案设计解决了该难题。在对图像传感器的工作原理进行了深入分析的基础上,建立了相应的调制传递函数；为确保成像测量系统具有较高的空间分辨率,对光学系统及其景深和几何畸变校正等进行了深入研究,并建立了相应的数学模型,重点研究了测量系统在大视场角的条件下同时具有高空间分辨率、大景深和小几何畸变的相关技术,通过设计和调控光学焦距、光瞳大小和光学系统的结构参数等技术途径,较好地解决了在特殊条件下,实现大视场角、大景深、高清晰度、高逼真地获取火炮膛内复杂图像的技术难题。二、光电图像处理、测量方面1.针对测量系统所获取图像的特点和测量的特殊要求,研究并设计了相应的图像预处理、图像分割和图像校正方案和算法。在研究多种图像预处理算法的基础上,提出了一套高效的图像预处理算法,实验证明该算法能在增强图像的同时有效地保持高精度图像测量所需的图像细节；作者通过对多种图像分割算法的深入分析和实验研究,确立了一种适应本测量系统的最佳分割方案—自适应双阈值分割方案；图像的空域处理主要包括光靶同心圆区域的自适应划分、同心圆参数检测、图像几何畸变校正、激光光斑形心检测等多个环节。2.研究了高精度图像测量的算法。针对被测图像是图像和图形混合体的特点,研究并设计了将其先分后合的测量算法,即先对多个同心圆形和激光光斑图像实施亚像素检测,然后将其合并计算,从而不仅可实现高精度图像测量,而且同时完成了测量数值的现场定标。作者不仅设计并实现了对所获取图像的上述特殊处理和高精度测量的整套算法,而且可将测算结果形成的离散数据自动生成身管弯曲度图形曲线并直观地显示在监视器屏幕上。另外,本文还对激光光束在空气介质中传输产生的漂移对测量结果产生的不良影响进行了分析和估算。更多还原

【Abstract】 The measurement of cannon static parameters is a prerequisite and importance technique process in studying, designing and using of modern cannon. The laggard measurement method based on optics glass and data processing artificiality can not satisfy new requirement that following progression of cannon development, manufacture level and using requirement. It is must to build high efficiency, precision, automatism measurement system. This dissertation studies on key technique such as photoelectricity imaging and image processing thoroughly in cannon static parameters measurement system that developed by us and based on laser collimation and CCD imaging.On foundation of lucubratting for measuring principle, measuring method and performance and limitation of the active furnishment about non-straightness of barrels and chamber parameters of cannon, the precept of non-straightness of barrels measurement system based on laser collimation and CCD imaging was presented and realized. Two aspects that photoelectricity image acquirement in the special environment and precision image measurement were studied as pivot. The scene state control in photoelectricity image and optical system precept for close quarters and fine definition imaging that based on special environment of cannon chamber were studied and designed. The precept and arithmetic of image pretreatment, image calibration and precision image measurement based on special image that acquiring were founded. These precept and arithmetic were application in the engineering development of cannon static parameters measurement system already that passed through theories studying and calculating machine simulate optimization and achieved the anticipative purpose. Main contents that studied in the dissertation was:1. Photoelectricity image acquisitiona. Contraposing the special imaging environment that is difficulty to imaging by general technique because complexity structure, surface smooth and clean, the complicated reflected ray in cannon chamber. The illumination distributing condition and corresponding environment was founded that the distinctly imaging request was founded by simulating imaging and image process technique. The illumination distributing environment that requiring by high quality imaging of CCD camera was founded by adopting separate cold lamp-house and through optical technique such as ray scatter, reflection, addition and compensate. And the illumination environment can adapt different cannon chamber and insure imaging best by adjust the collocate parameters of lamp-house.b. Studying the photoelectricity imaging thoroughly that requiring measurement system possess the special short distance and big angle of view in image information acquisition. Analyzing the primary factor and technique difficultness that effect imaging quality in special requirement. That is non-uniformity distributing of definition bringing by the limitation of depth of field of optical system. This difficultness was resolved by mathematics modeling and optimization. The MTF was founded by analyzing the principle of image sensor thoroughly. The resolution, depth of field and calibration of aberration of optics system was studied thoroughly and the mathematics model was founded insuring that imaging measurement system possess high space resolution. The technique that system possess high space resolution, big depth of field and small aberration synchronously was studied emphatically. Realize to acquire complicated image within cannon chamber with big angle of view, long depth of field, fine definition and high fidelity in special condition by design and control parameters such as focus length, size of diaphragm and structure size of optical system.2. Image process and measurementa. Studying and designing the precept and arithmetic of image pretreatment, image segmentation and image calibration by contraposing characteristic of acquiring image and special requirement by measurement system. A set of high efficiency arithmetic was presented by studying multifold image pretreatment arithmetic. It was proved by experiment could enhance image and preserve image detail that required by measurement at same time. The optimal precept of image segmentation that self-adaptive double threshold segmentation was established through studying multifold image segmentation arithmetic thoroughly. The image space process mainly involves concentric circle region self-adaptive parting, examining the concentric circle parameters, calibration the geometry distortion, ascertainment the centroid of laser spot.b. Studying arithmetic of high precision image measurement. Studying and designing arithmetic that departing first and then uniting by contraposing characteristic of measuring image is mixture of image and graph. That is detecting concentric circle and laser spot by sub-pixel and then calculate it unite. This arithmetic not only realized high precision image measurement, and furthermore, it achieved calibrating measuring data locale.The author not only designed and realized series arithmetic of special processing and high precision measurement for acquiring image, further more, the measure curve was created automatically by separate data formed by measurement was displayed on the screen of monitor straightforward. Otherwise, The badness effect to measurement that laser beam shift brings by transmission through air medium was analyzed and estimated.更多还原