Development of an Economical 3D Sensor for Weld Seam Tracking in Robotic Welding

Achieving quality weld in robotic arc welding processes is challenge due to workpiece fixture accuracy and variation in workpiece manufacturing processes. Many methods have been developed to measure the dimension of weld seam and thus make adjustment of welding robot paths to achieve quality weld. However most of the measurement sensors are quite expensive and not easy to be integrated into the robotic welding systems. Therefore, an economical 3D measurement sensor based on structured light technique is proposed in this paper. Calibration methods of the sensor are investigated. Experiments for sensor calibration were performed. After the sensor was calibrated, seam tracking experiments were implemented to validate the proposed sensor. The experimental results show that the proposed sensor can be used for seam tracking with acceptable accuracy. Therefore, it will decrease the investment of robotic arc welding equipment while achieving quality weld.