Visual positioning of rectangular lead components based on Harris corners and Zernike moments
来源期刊：中南大学学报(英文版)2015年第7期
论文作者：WANG Zu-jin HUANG Xiao-diao
文章页码：2586 - 2595
Key words：visual positioning; Harris corners; Zernike moments; edge detection; sub-pixel; image registration
Abstract: With the increasing necessities for reliable printed circuit board (PCB) product, there has been a considerable demand for high speed and high precision vision positioning system. To locate a rectangular lead component with high accuracy and reliability, a new visual positioning method was introduced. Considering the limitations of Ghosal sub-pixel edge detection algorithm, an improved algorithm was proposed, in which Harris corner features were used to coarsely detect the edge points and Zernike moments were adopted to accurately detect the edge points. Besides, two formulas were developed to determine the edge intersections whose sub-pixel coordinates were calculated with bilinear interpolation and conjugate gradient method. The last experimental results show that the proposed method can detect the deflection and offset, and the detection errors are less than 0.04° and 0.02 pixels.
WANG Zu-jin(王祖进), HUANG Xiao-diao(黄筱调)
(Department of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, China)
Abstract:With the increasing necessities for reliable printed circuit board (PCB) product, there has been a considerable demand for high speed and high precision vision positioning system. To locate a rectangular lead component with high accuracy and reliability, a new visual positioning method was introduced. Considering the limitations of Ghosal sub-pixel edge detection algorithm, an improved algorithm was proposed, in which Harris corner features were used to coarsely detect the edge points and Zernike moments were adopted to accurately detect the edge points. Besides, two formulas were developed to determine the edge intersections whose sub-pixel coordinates were calculated with bilinear interpolation and conjugate gradient method. The last experimental results show that the proposed method can detect the deflection and offset, and the detection errors are less than 0.04° and 0.02 pixels.
Key words:visual positioning; Harris corners; Zernike moments; edge detection; sub-pixel; image registration
