基于图像处理技术的多指针水表自动校验系统

发布时间：2018-03-15 01:12

本文选题：水表校验　切入点：VB.NET　出处：《山东大学》2015年硕士论文　论文类型：学位论文

【摘要】：水表生产企业所生产的水表,出厂前都需要对其进行检定,只有达到检测精度才能投放到市场。现在应用的水表校验系统,大多采用人工操作的方法,需要手工抄读测量结果并进行水表误差的计算,这种人工校验方法,不仅检定效率低,工作强度大,而且检定结果极易受人为因素的影响。为了克服人工抄表校验过程中所带来的各种弊端,本文设计了一款基于图像处理技术的多指针水表自动校验系统。此校验系统利用机器视觉技术及图像处理技术相结合的方式,来代替人工完成对水表数据的读取和处理工作,进而完成对水表的校验,不仅可以节约大量的劳动力还可以提高生产效率,减小人为因素所造成的影响。此水表校验系统是基于VB.NET开发平台进行设计的,通过对此校验系统的测试和分析证明,本论文所设计的校验系统方案是可行的,且取得了较好的校验结果。本文所研究的主要内容为：1、图像读取模块：采用CMOS摄像头带有的USB数据线将其与计算机相连,调用摄像头的动态链接库来进行水表图像的摄取,当水表流过标定体积的水流量之后,进行水表图像的采集,再将采集的水表图像转换为RGB格式的图像保存到指定的文件夹中。2、图像处理模块：通过Matlab对所摄取的水表图像进行处理,处理方法为：将RGB格式的水表图像转换为YCbCr格式的水表图像,对转换后图像进行灰度变换,对灰度图像进行腐蚀膨胀去噪,之后对其进行二值化处理,对处理后图像利用Canny算子提取水表指针边缘,对边缘图像进行膨胀处理以实现对水表指针边缘的粗化操作,为得到更多的边缘像素点以提高后续利用Hough变化确定指针圆心坐标的精度,对粗化的指针边缘利用Hough变换确定对应于各边缘的唯一的圆心坐标,然后进行水表指针尖端的识别,利用建立的坐标系确定水表指针的旋转角度,并通过标准图像对其进行校正,计算出指针旋转角度所对应的数值,利用表盘各位的对应关系对此数值进行校正,最终确定水表读数。3、数据处理模块：利用SQL Server建立水表校验数据库,将经过校验得到的水表数据插入到数据库中的数据表所对应的数据列中,对水表的误差进行计算,若分别处于规定的1.5%和4%误差范围内,则水表合格,否则判断为不合格,为以后的水表封装工作提供依据。系统从数据库中提取水表校验数据进行相应的查询操作,打印成Excel报表方便以后的数据审核和处理工作,还可以根据测试需要对数据库进行清空操作。4、连接动态链接库模块：本文利用VB.NET搭建了系统校验平台。系统调用摄像头的MVCAMSDK.DLL,实现对摄像头的相关设置及对图像的摄取和存储操作。作者设计了Matlab动态链接库并对其进行调用,实现对水表图像的相关处理操作。
[Abstract]:The water meters produced by the water meter manufacturers need to be verified before they leave the factory, and only when they reach the test precision can they be put on the market. Most of the water meter verification systems used now use manual operation methods. It is necessary to read the measurement result by hand and calculate the error of water meter. This manual calibration method not only has low verification efficiency, but also has a large working intensity. Moreover, the verification results are easily influenced by human factors. In order to overcome all kinds of malpractices brought by manual meter reading and checking, In this paper, a multi-pointer water meter automatic calibration system based on image processing technology is designed, which uses the combination of machine vision technology and image processing technology to replace manual reading and processing of water meter data. Furthermore, the calibration of water meter can not only save a lot of labor, but also improve the production efficiency and reduce the influence caused by human factors. The system is designed on the basis of VB.NET development platform. Through the test and analysis of the calibration system, it is proved that the scheme designed in this paper is feasible. The main content of this paper is: 1, image reading module: the USB data line with CMOS camera is used to connect it to the computer, and the dynamic link library of camera is used to capture the image of water meter. When the water meter flows through the calibrated volume of water flow, the image of the water meter is collected. Then the image of the collected water meter is converted to the image of RGB format and saved to the designated folder. The image processing module: the image of the water meter is processed by Matlab. The processing methods are as follows: the water meter image in RGB format is converted to the water meter image in YCbCr format, the transformed image is transformed into gray scale image, the gray image is corroded and expanded to denoise, and then the binary processing is carried out. After processing, the edge of water meter pointer is extracted by Canny operator, and the edge image is expanded to realize the coarsening operation of water meter pointer edge. In order to obtain more edge pixels to improve the accuracy of using Hough change to determine the center coordinates of the pointer, the Hough transform is used to determine the unique center coordinates corresponding to each edge of the coarse pointer edge, and then the water meter pointer tip is recognized. The rotation angle of water meter pointer is determined by using the established coordinate system, and corrected by standard image, the corresponding value of pointer rotation angle is calculated, and the value is corrected by the corresponding relation of each member of the dial. Finally determine the water meter reading. 3, data processing module: use SQL Server to establish the water meter calibration database, insert the calibrated water meter data into the data column corresponding to the data table in the database, and calculate the error of the water meter. If the water meter is within the specified error range of 1.5% and 4% respectively, the water meter is qualified, otherwise it is judged to be not up to standard, which provides the basis for the later encapsulation work of the water meter. The system extracts the check data of the water meter from the database to carry on the corresponding query operation. Printed as a Excel report for future data audit and processing, The database can also be emptied according to the test needs. 4, connecting the dynamic link library module: this paper uses VB.NET to build a system verification platform. The system calls the camera MVCAMS DK.DLLLL. the system can set up the camera and image. Ingestion and storage operations. The author designs and invokes the Matlab dynamic link library, To achieve the water meter image processing operation.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP391.41;TH814.2

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