Method and apparatus for picking and placing a surface mounted device with the aid of machine vision

摘要

A method for accurately placing a surface mounting device (SMD) with a vacuum nozzle analyzes a video image of the SMD to locate the SMD leads and compute corrections. The positions of the lead centers are processed to determine the translation and rotation of the SMD relative to a desired location. The position of the SMD centroid is transformed from an image-referenced coordinate system to a space-referenced coordinate system. The SMD rotation relative to a desired orientation is derived from the slope of a line drawn through colinear SMD leads.