Development of an Optical Inspection System for the Metal Component

• Main Authors: Jhen-Yu Wu, 吳鎮宇
• Other Authors: Geo-Ry Tang
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/fb7ker

碩士 === 國立臺灣科技大學 === 機械工程系 === 105 === This work has successfully developed an automatic optical inspection system for metal component. The hardware of the system includes a platform which is driven by linear motors. The image acquisition module on the platform can be set at high, medium, or low brightness for different applications. The software can process images obtained from specific brightness level so that the flaws on the component surface such as bumps, electroplating defects, spots, impurities and burrs can be detected. Once an image available, the self-coded program divides it into four segments , i.e. the radial lines, the inside of the ring, the ring surface and the edge of the ring. The bumps on radial lines are highlighted by subtracting images of two brightness levels. It is found that the reflection of metal surfaces has significant influence on the accuracy of the inspection process. The defects on the inside of the ring can be effectively detected by the high brightness images. However, high brightness, low brightness and subtracted images are suggested for detecting larger impurities, small spots and electroplating defects on the ring surface separately. In addition, wavelet transform is used to capture low-frequency signals to distinguish flaws from normal reflection on the high brightness images. After coordinate transformation to polar system, burrs along the edge of the ring area can be easily identified. Finally, samples including normal and defected parts have been tested to verify the capability of the inspection system developed.