Research On Laser Weld Sensor Calibration System Based On Machine Vision

Laser welding sensor parameter calibration has very important practical significance in the field of robot weld research,so it is urgent to develop a fast and practical industrial field parameter calibration method to adapt to the field of efficient automated welding production.The calibration contents of this paper mainly include: camera internal and external parameter calibration,structural light plane calibration and welding robot hand eye calibration three steps.The calibration of the parameters in the camera includes the determination of the camera's main point,focal length and external parameter matrix.This part of the calibration is realized by the Matlab classic toolbox Camera Calibrator.The structured light plane is calibrated,and the checkerboard calibration plate is used.The structural light plane equation can be obtained based on the cross ratio invariance method.The hand-eye calibration is performed by controlling the robot to make the six-axis robot end welding gun perform multiple attitude changes,recording the specific readings of the teaching device in each posture,combining the values under the feature point camera coordinate system,and then obtaining the rotation matrix and the translation vector,thereby obtaining the rotation matrix and the translation vector.The eye changes the relationship.Finally,the feasibility of the welding measurement verification calibration method is carried out.In this paper,the whole weld seam tracking system is calibrated as a whole.During the calibration process,the weld seam image processing technology is deeply studied to obtain the location information of the weld feature points.Based on the traditional structured light measurement and combined with the special working background of the welding environment,this paper develops a laser welding special sensor and calibration platform that meets the requirements of the welding process,and feeds the position information of the weld obtained by the sensor to the robot to guide the robot movement..The data verification calibration method obtained by experiments is accurate and reliable,the calibration steps are clear and reasonable,and easy to implement,and the laser welding seam sensor accuracy after calibration meets the requirements of industrial field welding process.