【作者】 卢泉；

【导师】 刘上乾；

【作者基本信息】 西安电子科技大学 ， 物理电子学， 2010， 博士

【摘要】 特殊管道在航天、能源、化工、武器等众多领域有着广泛的应用,其静态参数测量是管道设计、研究和使用过程中的关键技术环节之一。随着特殊管道的研制水平、生产工艺以及使用要求的不断提高,我国现有的测量设备难以满足当前的测量需要,因此研究高精度、高效率和自动化的特殊管道静态参数测量技术具有重要的理论意义和工程应用价值。本文在研究相关测量设备的技术现状、局限性以及充分了解用户使用要求的基础上,设计并实现了一套高性能的特殊管道静态参数测量系统。论文针对特殊管道静态参数视觉测量中的技术难点,详细而深入地研究了特殊管道测量环境下视觉测量分系统的优化设计、靶标图像的预处理、基于图像测量的高精度定位和静态参数测量的实现等关键技术,并提出了相应的解决方案。1.对特殊管道测量环境下的视觉测量分系统进行了优化设计：设计并实现了适合特殊管道内视觉测量所需的均匀照明光源,建立了最优景深的数学模型,利用该模型对光学成像进行了优化设计,实现了测量靶标的清晰成像。2.针对靶标图像的噪声多样性、低对比度等特点,设计并实现了相应的图像预处理方法：提出了一种基于局部梯度模的混合噪声抑制算法,有效地消除了多种噪声对靶标图像的不良影响；设计了一种基于模糊推理的自适应分段非线性图像增强方法,改善了靶标图像的对比度；针对不同的靶标图像,采用基于边缘检测的局部最大类间方差法阈值法,对其实现了准确的分割。3.利用测量靶标实现了特殊管道内视觉测量中的摄像机的现场标定和校正：针对特殊管道身管弯曲度的测量,提出了一种基于同心圆靶标现场标定的畸变校正方法；为了适应变锥度内腔参数的测量,设计了一种基于标尺刻度特征的畸变校正方法。利用上述方法对特殊管道内视觉测量中的摄像机进行标定和校正后,在一定程度上提高了系统的测量精度。4.针对不同的测量靶标,设计并实现了相应的基于图像测量的高精度定位方法：提出了一种基于特征角点匹配聚类的自适应靶标定位方法,有效地消除了进深扰动对靶标定位所引入的不良影响；提出了一种基于几何特征约束残差修剪的光斑定位方法,实现了靶标上复杂激光光斑的高精度定位；提出了一种基于块匹配灰度补偿的滑动标尺刻度精确定位方法,克服了光照环境变化对标尺刻度定位的不良影响。5.针对复杂管道内的苛刻测量要求,设计并实现了静态参数的高精度测量方法：提出了一种基于双激光准直CCD的弯曲度测量方法,克服了进深测量过程中随机扰动所引入的不良影响,提高了方位角的测量精度；设计了一种基于滑动正交双标尺的变锥度内腔参数测量方法,实现了变锥度内腔参数的大动态范围、高精度测量。最后,对系统测量误差和误差来源进行了深入的分析,提出了相应的误差补偿方法。更多还原

【Abstract】 The special type tube is widely used in many fields such as aerospace, energy, chemical industry, weapon system and etc. Measurement of the static parameters is a key technique process in designing, studying and using of the special type tube. With the development of study, manufacture of production and requirement of application, higher requirement is proposed for the measurement system, but it can not be fulfilled by the present measurement system. So it’s very importance of theoretical significance and engineering value to develop a kind of high precision, efficiency and automatism measurement system.By thorough study of the measuring principle, measuring method, performance and limitation of the special type tube, a tube static parameters measurement system with high quality is designed and accomplished. Focused on the difficulty of technology in the special tube parameter measurement, the optimization of the visual measurement sub-system, image pre-processing of target, high precision location based on image measurement, and method of system parameter measuring is studied deeply and particularly, and the corresponding solution is proposed.1. Optimization of visual measurement sub-system is operated in the special type tube environment.An even illumination source is designed and realized for the visual measurement in the special type tube. The mathematical model is proposed for the optimal depth of field, which is used to optimize the optical imaging, so that the clear target image is acquired.2. According to the image characters of measuring target, the corresponding pre-processing algorithms are designed and implemented for the target image.An algorithm based on the local gradient is proposed to remove many kinds of noise on the target image, so that the noise can be removed effectively. In order to enhance the acquired image, a self-adaptive algorithm based on nonlinear sector-by-sector transformation with fuzzy logic is proposed, as a result, the contrast of target image is improved significantly. Aiming at different target image segmentation, a local domain otsu threshold method based on edge detection is proposed, so the precise segmentation of target image can be achieved.3. By using the measurement target, the onsite calibration is carried out for the camera of the visual measurement in the special type tube.A distortion calibration method with concentric circles as onsite standard is proposed to the curvature measurement of special tube, and another distortion calibration method based on scales property is designed for the static parameters of variable taper tube, as a result, the measuring precision of system is improved by using the methods proposed.4. For different measurement targets, the corresponding location methods of high precision are designed with realization.A self-adaptive location method based on feature corner match and cluster is proposed, so the influence of the moving disturbance can be eliminated effectively. Another method based on residual prune with geometric feature constraints is proposed for the complex laser spot on the target, and the precise center location can be obtained. The precision location method based on gray compensation of block match is proposed for the moving target scale, and the influence of the illumination change can be overcome.5. To fulfill the steep requirement of measurement in the complex tube, high accuracy measurement methods for the static parameter are designed with realization.A method based on CCD dual-laser collimation is proposed to overcome the influence of random disturbance in the moving measurement. Another method based on moving and crossing scales is proposed, the static parameters measurement of variable taper tube can be gained with high accuracy and large dynamic range.Finally, the errors of measurement and the sources of error are analyzed thoroughly for the tube static parameters measurement system, and the corresponding error compensation methods are proposed.更多还原