A Product Logo Surface Defect Detection System Based On Machine Vision

With the development of science and technology and the progress of the society,more and more manufactures pay more attention to the logo's design,so as to improve the impact of their products and enhance the soft power of the company.In order to ensure the logo's appearance quality,manufacturers pay more attention to the defect inspection of surface quality.In this thesis,the object to be detected is a product logo machining from aluminum alloy sheet,according to the surface quality detection scheme based on Machine Vision was built,which composed of a high resolution GigE CCD produced by IMI Technology,Korea;SHI-PCIE-541T2 dual-port NIC;VS-LZ0510/F Industrial prime lens produced by VS,Japan;LED Dome-type shadowless light source and data processing computer.Get logo images with this image acquisition device,and through the digital image processing algorithms to determine whether the surface defects and defect categories.The system uses LabVIEW as a software platform for image processing algorithms,it has high efficiency and convenience of the graphical programming language.Through NI Vision function module and MATLAB mixed programming method,this object realized image acquisition,preprocessing,thresholding,morphological processing,mask defect identification and other functions.The system can effectively suppress the background noise thereby extracting defect characteristics,determining whether the logo's surface have defects or not and classifying the defect based on its characteristic parameters.Finally,the results would be transmitted to the programmable controller S7-200 PLC through serial communication,then PLC could make the appropriate motion control based on the received signal.Experimental results show that the system can accurately and efficiently determine logo surface quality qualified or not,and according to the characteristics of the logo of the defect classifying surface defects.Compared with traditional manual inspection,the method based on Machine Vision greatly improves the detection accuracy of the testing standards to ensure consistency.This object based on Machine Vision for logo's surface defect,it is a high-efficiency,high-precision testing method,improving productivity while reducing labor costs.