基于红外热成像技术的电路板故障检测方法研究

发布时间：2018-12-11 23:08

【摘要】：科技发展为电路板传统检测方法带来挑战,传统检测方法不能更好满足电路板检测及维护需求。红外热成像技术作为一种新型手段,将逐渐被应用于该领域中。本文首先对红外热成像技术以及故障检测方面的国内外发展现状进行了分析,并对红外检测技术相关理论进行了详细的论述,在此基础上分别阐述了基于红外热成像技术的电路板故障检测方法实现过程中,红外图像处理的必要技术措施和手段。本文利用红外成像技术,对出现故障的待测电路板和正常工作的标准电路板进行研究。在相同条件下由于待测板故障元件区域温度分布和标准板同一区域温度分布存在差异,会产生不同的红外图像,以此作为故障检测的依据,并以差分检测法和热序列检测法相互结合进行电路板的故障检测。差分检测法需要利用电路板的红外图像,然而在利用红外热像仪获取红外图像时,由于红外镜头的分辨率、拍摄角度的不同会使拍摄到的红外图像出现偏差,因此需要对其进行必要的图像预处理、配准等工作。图像配准的目的是消除空间位置差异,前提是图像预处理,本文预处理工作包括红外图像增强、去噪。为了实现红外图像增强,本文在直方图均衡化和高通滤波增强的基础上提出加权平均增强的处理方法,增强效果比单一方法更明显。另外,图像增强的同时噪声也得到增强,需要去对红外图像去噪处理。本文通过对不同的图像去噪方法进行分析比较,并对中值滤波法作出改进,经实验验证该算法对去除噪声有明显效果。本文通过设计故障判断流程并搭建了实验平台,通过实验验证表明本文设计的电路板故障检测方法可行,具有较高的故障检测率。
[Abstract]:The development of science and technology brings challenges to the traditional detection methods of circuit boards, which can not better meet the needs of circuit board detection and maintenance. As a new method, infrared thermal imaging technology will be gradually applied in this field. In this paper, the development status of infrared thermal imaging technology and fault detection at home and abroad are analyzed, and the related theories of infrared detection technology are discussed in detail. On this basis, the necessary technical measures and means of infrared image processing in the realization of the circuit board fault detection method based on infrared thermal imaging technology are described respectively. In this paper, infrared imaging technology is used to study the test circuit board and the standard circuit board. Under the same conditions, different infrared images will be produced because of the difference between the temperature distribution of the fault elements and the temperature distribution of the same area of the standard board, which can be used as the basis for fault detection. The differential detection method and the thermal sequence detection method are used to detect the fault of circuit board. The differential detection method needs to use the infrared image of the circuit board. However, when using the infrared thermal imager to obtain the infrared image, because of the resolution of the infrared lens, the different shooting angle will cause the error of the infrared image. Therefore, it is necessary to do the necessary image preprocessing, registration and other work. The purpose of image registration is to eliminate the spatial position difference, and the premise is image preprocessing, which includes infrared image enhancement and denoising. In order to achieve infrared image enhancement, this paper proposes a weighted average enhancement method based on histogram equalization and high-pass filter enhancement. The enhancement effect is more obvious than the single method. In addition, the noise is also enhanced while the image is enhanced, so it is necessary to de-noise the infrared image. In this paper, different image denoising methods are analyzed and compared, and the median filtering method is improved. The experimental results show that the algorithm has obvious effect on noise removal. In this paper, the fault judgment flow is designed and the experimental platform is built. The experimental results show that the circuit board fault detection method designed in this paper is feasible and has a high fault detection rate.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN407;TP391.41

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