An Automatic Welding Seam Extraction Method for Butt Workpieces with Varying Seam Widths Based on DLP Vision

Abstract

Planar butt seams are common in industrial sites, while the current seam extraction schemes are difficult to cope with butt seams with varying widths. Based on DLP (Digital Light Processing) vision technology, this paper proposes an automatic seam extraction method to solve this challenge. Firstly, we calculate different-granularity contour points based on the Alpha Shape algorithm, then extract seam feature points by calculating specific distance information. Secondly, we construct a type of 2D reference coordinate frame by analyzing the structural characteristics of the workpiece, then conduct a dimensionality reduction transformation on the feature points. Finally, we design an algorithm for curve fitting and discrete interpolation, which can generate the ordered interpolation points for welding. The experimental results demonstrate that the proposed seam extraction method can accurately, robustly, and efficiently extract the butt seams with varying widths.