Applications of Machine Vision and Subpixel Techniques in Socket Inspection

• Main Authors: Su, Cherng Tzong, 蘇成宗
• Other Authors: Chen Fei Long
• Format: Others
• Language: en_US
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/31209123898528247791

碩士 === 國立清華大學 === 工業工程研究所 === 82 === The employment of a machine vision system for part inspection has become an important component for achieving the goal of real-time control. However, one of the major constraints of this technique is its limited accuracy owing to the pixel resolution. For those applications which require better accuracy, such as photogrammetry and precision measurement, the accuracy can be improved by replacing with better hardware devices or by applying the subpixel techniques. In this research, we intend to develop new machine vision techniques to solve the problems encountered in practical manufacturing environment, with emphasis on accuracy problem. Linear estimation for LOG operation (LEFLO) method and weighted average (WA) method are proposed in this research. The LEFLO method applies the Laplacian of Gaussian convolution and localizes the edge with linear interpolation. WA method uses the deviation of gray values of successive pixels as the weight numbers to estimate the gray level of the edge translation. In this research, the synthetic images are employed to evaluate the effectiveness of the algorithms. The experimental results show that LEFLO is more accurate than WA when images are not disturbed by the environmental noise. Nevertheless, LEFLO is more sensitive to noise. The weighted average method requires less processing time than LEFLO method. It is almost one-sixty of the processing time of the LEFLO method. Finally, an integrated system for socket inspection is developed to illustrate its capability real-time inspection.