Time Synchronization of Laser Scanner and Robot

Abstract

On this paper, a study of robot based remote laser welding technology for manufacturing light car body was conducted. Laser welding and industrial robotic systems were used with robot-based laser welding systems. The laser system used in this study was 1.6kW fiber laser, while the robot system was Industrial robot (payload : 130kg). The robot-based laser welding system was equipped with a laser scanner system for remote laser welding. Laser patterning on the fly needs to control some parameters to accomplish the desired shape and good quality of the welded pattern. The scan path and the mark speed as two control parameters of the laser scanner are numerically computed from pattern shape and robot motion. However, time-delay in operation of the laser scanner and the robot makes unexpected geometric error between the desired pattern and the welded pattern. The pattern sequence and the robot path is optimized to reduce total processing time. The proposed method is tested with various patterns and robot paths, and the welded patterns are validated by measuring their geometries and positions. Finally, the experimental results show that our method is suitable for laser patterning on the fly. The welding joints of steel plate and steel plate coated with zinc were butt and lapped joints. The quality testing of the laser welding was conducted by observing the shape of the beads on the plate and the cross-section of the welded parts, analyzing the results of mechanical tensile test. The remote laser welding system with laser scanner system is used to increase the processing speed and to improve the efficiency of processes. This paper proposes the robot-based remote laser welding system as a means of resolving the limited welding speed and accuracy of conventional laser welding systems.