Automated robotic welding systems often use a preprogrammed path to guide the welding torch along the seam to be welded. This process cannot take into account differences in part positioning or warpage of the part while welding. The result is often poor quality welds. Adding a seam tracker to the system can alleviate this problem by modifying the path of the robot to suit the part it is welding.; The goal of this research is to develop a seam tracking system that is capable of locating the seam and controlling the torch position, orientation, and velocity in real-time. The system is to be installed on a standard industrial robot with the ability to receive torch height and travel speed commands from a weld control system.; A laser triangulation sensor and hardware preprocessor were used to capture an image of the surface profile of the workpiece. The software routines developed analyse this image to find the position of the seam and calculate the necessary corrections to the orientation of the torch. The trajectory of the robot is calculated in real-time using the position of the seam and the torch height and travel speed commands received from an external weld control computer.; The seam tracking system was tested in the harsh environment of GMA welding and successfully guided the torch along the seam. The geometric following capabilities of the seam tracker were tested with a complex test seam. The results show that the seam tracker was able to follow a complex three-dimensional path. Good results were also obtained from the travel speed response and accuracy testing.
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