Method And Application Of Robot Trajectory Tracking Based On Line-structured Laser 3D Vision

In this paper, Line-structured Laser 3D Vision System is designed with PC, frame grabber, industrial camera and laser. Robot Control System is built with PC, motion control card, servo drives and industrial robot. These two parts constitute the Robot Trajectory Tracking System. The pose of the robot tool can be determined according to the 3D coordinates of the target, which is obtained by the 3D vision system. Real-time tracking of the trajectory is suitable for seam tracking, contour scanning and other occasionsThe main contents are included.(1) Robot controlD-H model and kinematics forward and inverse solution function are programmed in the Matlab robot toolbox. The robot can move on six degree of freedom or from point to point under the control of motion control program designed on MFC.(2) 3D Vision SystemThe 3D Vision System based on line-structured laser is designed to recognize different shapes of trajectory contour, for example, lap, butt and V-shaped groove. Robot trajectory tracking method and program are designed according to the track points.(3) Calibration of the Robot Trajectory Tracking SystemEach part of the entire system needs to be calibrated, including the kinematic calibration of the robot, camera calibration, laser calibration and robot hand-eye calibration. Absolute positioning accuracy of the robot is increased to 1mm after the measurement of the laser tracker and the modification of D-H parameters. Inner parameters of the camera, external parameters of the laser and hand-eye transformation matrix of the robot are obtained by the vision system calibration base on Halcon. Finally the coordinates of the target can be measured in the robot base coordinate system.(4) Tracking experiment and analysisThe tracking experiment verifies that the tracking method and the calibration in this paper are feasible. The Robot Trajectory Tracking System achieves real-time tracking of wavy line, polyline and linear trajectory at the speed within 10mm/s and the average error is about 0.5mm.