产品表面缺陷在线检测方法研究及系统实现(分布式视觉).doc

产品表面缺陷在线检测方法研究及系统实现(分布式视觉)Study on Methodology of Product Surface Defects Online Detection and System Implementation【作者】彭向前 【导师】陈幼平; 周祖德【作者基本信息】华中科技大学，机械电子工程，2008年，博士 【中文摘要】：随着生产和工艺的进步,人们对产品的质量要求越来越高,基于机器视觉的在线检测系统成为一种重要的质量控制手段。本文对应用于宽幅面、高精度的基于分布式机器视觉的产品表面缺陷在线检测理论与算法进行了研究,并在此基础上以印刷品和浮法玻璃的缺陷检测为例,完成了模式产品和非模式产品的缺陷在线检测系统。根据产品表面检测中的宽幅面、高精度的特点,本文设计了一种分布式机器视觉的在线检测系统结构,采用多个图像处理子系统协同完成检测任务。本文提出了一种基于轮廓子空间的快速图像配准方法。该方法实现了一种基于方向的多分辨率形态学轮廓提取算法,设计了基于预测的双阈值轮廓点分割方法,应用了基于图像融合的基准图像更新方法,建立了对轮廓子空间的评价标准,在轮廓子空间上进行图像配准,降低了计算量,保证了图像配准的准确性和实时性。针对模式图像和非模式图像分别提出了不同的缺陷分割方法和伪缺陷剔除方法,并提出了一种基于顺序和行程长的缺陷快速聚类算法。本文设计了一种基于图像差分的模式产品缺陷分割方法,设计了一种基于阈值曲面的非模式产品表面缺陷分割方法。为了解决阈值曲面插值构建方法的巨大计算量和准确性,提出了一种基于方向统计的快速阈值曲面构建算法。针对模式图像上的轮廓伪缺陷,提出了一种基于边缘的伪缺陷剔除算法;针对浮法玻璃上昆虫、灰尘和油污等伪缺陷,提出了一种基于纹理的伪缺陷剔除方法。在对比各种模式识别方法的基础上,提取了缺陷特征,根据印刷生产和浮法玻璃生产对缺陷分类的不同要求,设计了一种基于规则的印刷品缺陷分类方法,实现了一种基于改进的BP神经网络的浮法玻璃缺陷分类器,解决了缺陷的快速识别问题。研究了分布式机器视觉系统中的同步和网络拥塞问题,解决了多图像处理子系统的同步问题;设计了一种基于RTT预测的改进拥塞控制方案;实现了分布式机器视觉系统的自诊断和自恢复。在上述算法和理论的基础上,开发两种专利产品,即浮法玻璃缺陷在线检测系统和印刷品缺陷在线检测系统,并成功应用于生产实际,取得了良好的经济和社会效益。【英文摘要】： With the advancement of manufacture and techniques, the product quality becomes increasingly important, and the online quality inspection system based on machine vision has been an important quality control method.This paper studies the online defects inspection theory and algorithms for product surface based on distribution machine vision, and implements the online defects inspection sytem of model product and non-model product using the defects inspections of presswork and float glass as the instances.Firstly, to meet the requirement of large dimensionality and high precision in product surface inspection, an inspection system based on distribution machine vision is designed, and several inspection sub-systems are used to complete the inspection task cooperatively.For settling image registration of model image, a fast contour sub-space based image registration algorithm is presented to aim at the large computing complexity of traditional image registration. To detect image contour fast and correctly, a direction based multi-resolution morphology contour detection algorithm is presented, and a forecast based bi-thresholding value contour segmentation is used to thresholding the contour pixels. An evaluative method of contour sub-space is established, and the images are registrated through the contour sub-space for improving the efficiency of image registration.As to fulfilling the detection tasks, different defects segmentation methods are designed for model image and non-model image, and a fast defect merging method based on sequence and journey space is presented in order to realize defect clustering fastly. A defect segmentation method based on image subtraction is designed to realize defect segmentation for model image. A defect segmentation method based on thresholding surface is presented to segment defects for non-model image, and a fast thresholding surface construction method based on the statistic of grey level is presented to solve the great complexity and inveracity of traditional interpolation method. A contour subtraction based fake defect discrimination method is designed to eliminate contour fake defects for model image inspection, and a texture based fake defect discrimination method is presented to tide over the fake defects such as insects, smeariness and dust.Based on the analysis of several pattern recognition methods, all kinds of defects characters are picked up. According to the different classification requirements of different production defects, a rule based defects classification method is designed for presswork defects, and an improved neural network based defect classification method is realized for float glass defects.The synchronization and network congestion of distribution machine vision system are also studied here. For meliorating the network congestion in distribution system, an improved congestion controlling mechanism based on the predictable RTT is proposed. Futhermore, a self-diagnosis and self-recovery mechanism is realized for distribution machine vision system.At last, based on the aforementioned theory and algorithms, two patent production, such as an online presswork defect inspection system based on distributio