Development of an Economical 3D Sensor for Seam Tracking in Robotic Welding
To satisfy an increasing demand for high-quality welds as well as shorter cycle time, robotic welding has been implemented in high-volume manufacturing processes such as automobile assembly. However, achieving high-quality welds in robotic arc welding processes is still challenging due to variations in workpiece geometries and inaccuracies of welding fixtures in manufacturing. Seam tracking has been studied by researchers as a possible solution to these problems and several methods have been developed to measure the weld gap dimensions and thus adjust welding robot paths to accurately follow the weld gap geometry. However, most of the existing measurement sensors are very expensive and only installed in high-volume manufacturing processes. Therefore, an economical 3D measurement system based on the structured-light technique is proposed in this research. To improve its precision, a calibration method for the sensor is developed and implemented. After the sensor is calibrated, weld gap measurements are then performed to verify the measurement accuracy of the 3D sensor. Finally, seam tracking experiments are conducted to validate the proposed sensor. Welding results showed that the proposed sensor has the potential to significantly decrease capital investment in robotic arc welding equipment while achieving high-quality welds.
structured-light, seam tracking, robotic welding, pixy2 camera
Okeke, H. (2021). Development of an economical 3D sensor for seam tracking in robotic welding (Unpublished thesis). Texas State University, San Marcos, Texas.