Automatic seam-tracking of friction stir welded T-joints

In this research, a method for implementing automatic seam-tracking for friction stir welding, referred to hear as WeaveTrack, is presented. In this extrumum-seeking control technique, the tool weaves back and forth during welding to maintain the location where axial force is greatest, which is shown to be the center of the weld. Results demonstrate the effectiveness of this technique in tracking both known and unknown weld seams. Comparisons of tensile test results of weaved and nonweaved welds, and findings in related literature, indicate that weaving’s impact on weld quality could be positive. Finally, methods for incorporating WeaveTrack seam-tracking into existing friction stir welding control systems (such as load control) are discussed.