A simple calibration method of structured light plane parameters for welding robots

Abstract

It is necessary to calibrate the structured light plane parameters in addition to the camera intrinsic parameters for structured light vision systems. Besides, structured light plane parameters calibration should be simple and practical on the premise of being accurate. In this paper, a simple calibration method of structured light plane parameters for welding robots is proposed. In the process of camera intrinsic parameters calibration, structured light plane parameters can be calibrated simultaneously. Two feature points on the laser stripe are extracted firstly. Then, another two feature points on the laser stripe are extracted while the robot moves from one calibrating position to another with constraints so that two misaligned laser stripes are generated. Then, the structured light plane parameters could be determined using four points on the structured light plane. What's more, special calibration objects and manual measurements are not required in this method. Therefore, it is a simple and practical calibration method. Finally, a calibration experiment and two vision measurement experiments are implemented. Experimental results show that the structured light plane calibration accuracy could meet the requirement of welding robot.