Extraction of Three-Dimensional Parameters for Weld Pool Surface in Pulsed GTAW With Wire Filler

Abstract

By viewing the topside of a weld pool, a skilled operator can estimate the weld joint penetration. The weld pool shape or the solidified bead shape is crucial for weld quality. Automatic control of pulsed GTAW with wire filler is achieved by recording the image of the weld pool with an optical sensing method and then calculating shape parameters with an image processing algorithm. Three-dimensional shape parameters of the weld pool were determined that uniquely and accurately describe various weld pool shapes. Two-dimensional shape parameters were extracted from a two-dimensional image processing algorithm. Finally, a shape from shading (SFS) algorithm on a single image was used to recover the surface height from a single weld pool image. The extracted three-dimensional parameters for the weld pool surface were verified and used for double-sided shape control.