【作者】 李强；

【导师】 王义文；

【作者基本信息】 哈尔滨理工大学 ， 机械工程（专业学位）， 2017， 硕士

【摘要】 近年来,编码器被广泛的应用在各行业,市场的需求量大比重增加,而这也促进了编码器生产商的技术水平不断完善。编码器是使用圆光栅片做信号存储元件,测量精度高、运行状态平稳性好、可使用区间较广、占用空间小、质量轻、功率低和成本低等优点,其质量直接影响到使用性能。由于光栅片制造工艺的限制,其表面往往会产生星点、铬点、毛刺、断线等缺陷。目前,光栅表面缺陷的检测方式主要以人工检测为主,劳动强度大、主观性强、成本高,难以在精度、效率及自动化程度等方面满足检测要求。因此,本文应用图像处理技术,开发了光栅表面缺陷检测系统。首先,根据项目技术要求,对光栅夹具、二维平移台等机械结构进行了改进设计,并优化了控制系统参数,提高了系统的可靠性及控制精度,为稳定光栅图像的获取提供了保证。其次,针对光栅图像特点,进行了图像去噪、图像增强及运动模糊图像复原等图像预处理算法研究,并分析了常用的图像边缘重绘、边缘检测算法,提出了一种基于Canny算子的改进边缘重绘算法,保证了光栅表面轮廓特征的提取。再次,对预处理后的图像进行ROI截取,得到有效待检区域,并提取目标缺陷区域的几何特征,同时完成参数测量,实现了多种光栅表面缺陷的特征识别,并对缺陷区域进行标记。最后,设计了交互键盘、自动警示装置,并对软件系统进行了优化,提高了检测系统的可应用性。通过应用检测测试,发现检测系统的系统稳定性和检测效率等都有显著提高,实验表明,针对直径范围为33-38mm光栅,本文开发的光栅表面检测系统缺陷识别率在95%以上,误检率在5%以下,检测效率达29秒/个。更多还原

【Abstract】 In recent years,the encoder is widely used in various industries,which makes the market demand a large proportion of increase.As a result,this also promotes the technical level of encoder manufacturers constantly development.Encoder uses circular grating chip as the signal storage element.It has a certain number of advantages such as high measuring precision,good running state stability,wide use interval,small occupied space,light weight,low power and low cost,etc.Its quality directly affects the service performance.Because of the limitations of grating manufacturing,its surface tends to produce star,chrome point,burr,break and other defects.At present,the detection methods of grating surface defects are mainly manual testing,which has a lot of shortcomings such as high labor intensity,strong subjectivity,high cost,and difficult to meet the detection requirements in terms of accuracy,efficiency and automation,etc.Therefore,this topic develop a detection system of grating surface defect based on image processing technology.Firstly,the technical requirements of this paper are analyzed,and the key technology of grating surface defect detection is determined,where the Optimization of some hardware must be carried out,for example designing the grating universal fixture and optimizing the control parameters.Secondly,using the image processing technology,preprocess of grating surface image is conducted,and several image processing algorithms are proposed.Preprocessing algorithms for image denoising,enhancement,and restoration of blurred image caused by motion are researched.Traditional image edge algorithms such as edge redrawing,edge detection are analyzed,and then a special edge redrawing algorithm is used to extract the grating surface profile.Then,ROI intercepts for the preprocessed image are conducted,and theareas to be detected are obtained.Parameter measurements are implemented after extracting the geometric features of target defect area.Defect feature extraction is carried out and then various surface defects of grating are identified and the detected unqualified area will be marked by algorithm.Finally,the application of this system is studied,such as the design of interactive keyboard and automatic warning device,and the optimization of the software system.Then different specifications of the grating are selected to make a test by this system.The overall performance,detection results and detection efficiency are significantly improved.Experimental results show that the grating surface detection system developed in this paper is feasible and effective.The defect recognition rate is above 95%,that is,the detection error rate is below 5%.Aiming at the grating whose diameter is less than 33-38 mm,the detection efficiency is up to 29 seconds each.更多还原