The Study of Automate Locate Special Fiducial Marks

This study proposed an automatic positioning technology for the precision special fiducial mark(SFM). It divided the precision SFM into the fiducial mark of double circle and the fiducial mark of corner before positioning according to SFM. First, a standard fiducial mark (FM) known as reference fiducial mark (RFM) was selected. Then, according to RFM, the FM of other fiducial mark images was compared before locating the coordinates of the FM in the image. the double circle detection was to first cut the external circle and then cut the internal circle according to the relationship between the external circle and the internal circle. the corner detection determined the intersection of the two contour straight lines of the object. the experimental results proved that the proposed automatic positioning technology for special FMs can accurately locate the special FMs to save labor and avoid artificial measurement misjudgment and unnecessary harms to the operational personnel.