In order to identify the discontinuous welding seam created by drainage holes in lattice-type cabin in shipbuilding

a vision sensor is set up in the robot to extract the startpoint and the endpoint of drainage holes.The way of image acquisition and image processing procedure are introduced.The image of welding seam is denoised.Threshold segmentation are done and connected region and their area are striked.The image is refined and the frame of laser line is extracted.Characteristic line is extracted using Hough transform.The intersection of two lines is striked

which is the characteristic point of welding seam.So that drainage holes and welding seam are identified.Discontinuous welding seam tracking experiment on workpiece that similar to cabin are carried out

and the experiment is successful.