3D Reconstruction of Weld Pool Surface by a Biprism Stereo System

Abstract

3D shape of the weld pool surface can be used to infer the penetration state of the weld pool, which has an importance influence on weld quality. In this paper, a novel stereo camera system that used only one camera and a biprism placed in front of the lens was applied to capture virtual image pair of the weld pool surface. The most advantage of the system setup is that corresponding points lie on the same scan line automatically, i.e. the stereo image pair is self rectified. The calibration of the system was done using plane pattern by Zhang’s algorithm and the standard SSD stereo matching algorithm was applied to find the corresponding points in the left and right image. The reconstructed 3D shape of the weld pool surface during base current period of P-GMAW by the system has shown that the technique has potential application for control of weld process