A Novel Robotic Welding Method for Multilayer and Multi-pass Welding Process based on Vision Sensor

The existing multi-layer and multi-pass welding process normally adopts teaching-playback method in low-level automation. Also, it is difficult for this method to adapt to the diversity of workpiece by reason of its poor flexibility and universality. To solve this problem, this paper proposes a new robot system for multi-layer and multi-pass welding process based on vision sensor. Firstly, the mathematical model for the welding robot system is established to describe the spatial relationship between the coordinate systems of the tip of the robot, vison sensor and the tip of the welding torch. Then, the groove profile is reconstructed by the detected data of the vision sensor using the proposed data processing method. Based on the spatial model for the welding robot system and the groove profile obtained by the vision sensor, the mathematical model for the welding trajectory is established to realize the multi-layer and multi-pass welding process. Finally, the welding trajectory is verified in simulation and experiment, and the results demonstrate that the welding robot system proposed in this paper has a certain degree of reliability and feasibility.