A calibration algorithm of the structured light vision for the arc welding robot

Abstract

Structured light vision is now widely used in weld seam detection for arc welding robot due to its simple structure, high precision, low cost, and real-time characteristic. By taking use of optical triangulation measurement principle, the position of welding seam is able to be measured. Calibration is one of the crucial step before structured light vision can be actually used in the welding system. In this paper, a calibration algorithm of the camera and laser is deduced mathematically, which involves the calibration algorithm of intrinsic parameters, extrinsic parameters of the camera and the calibration algorithm of laser plane equation which respect to the camera coordinate system. A structured light vision system is implemented, consists of a CCD camera a linear structure laser and a calibration chessboard, to verify the validity and practicality of the algorithm. By measured the standard object, the experiment results are carried out and the measurement error are analyzed. The experiment results show that the calibration algorithm is able to meet the demands of accuracy for arc welding robot.