Research on Extracting Feature Points of Electronic-Component Pins

Most of the plug-in machine adopts the visual positioning system that is used by Surface Mount Technology (SMT), and obtains the bottom image of component. For some electronic components, as the color of pin is similar to the body, the pin is difficult to be distinguished. In order to improve the positioning accuracy of the rotational stereo vision positioning method for plug-in machine, an electronic component pin edge tracking algorithm based on iterative optimization and a sub-pixel edge extracted method based on the cubic curve fitting are proposed. Furthermore, a center point calculation method is proposed for component pin with different shape to improve the accuracy of feature point extraction. Experimental results show that the proposed center point calculation method performs higher accuracy than the method of taking average of borders as center point directly. In addition, the proposed subpixel border extracting method performs better accuracy than the Canny algorithm.