Weld pool surface depth measurement using a calibrated camera and structured light

Abstract

Automated monitoring and control of the weld pool surface has been one of the goals of the welding industry. This paper presents a technique which uses a calibrated charge-coupled device (CCD) sensor and structured light to extract the surface information as depth of pool from captured images. It projects a laser line from a predetermined position onto the specular weld pool surface. A reflected laser beam from the specular surface is captured by a calibrated CCD sensor to form the image. The image is then processed based on the ray-tracing technique to calculate the depth of the weld pool surface using the position of the laser and its fan angle along with the intrinsic parameters and extrinsic parameters of the CCD sensor.

Measurement of Calibrated Recursive Analytic in the Gas Tungsten Arc Weld Pool Model

“…The measurement of the weld pool surface to be used for calibration is obtained from an in-situ 3D weld pool surface sensor developed at the University of Kentucky (Refs. 36,37) as shown in Fig. 2.…”

Quality assessment in laser welding: a critical review

“…Through the visual analysis of the weld's acquired 3D profiles, the positions and sizes of the weld defects were accurately identified. Another quality assessment approach was presented in [35]. The authors used a calibrated coupled charged device (CCD) sensor and structured light to extract the surface information, as depth of pool, from the captured images.…”

A stereo vision method for tracking particle flow on the weld pool surface

“…1 As a noncontact technique, vision technology is one of the most attractive methods employed to obtain quantitative results during welding. Welding involves extreme conditions, including high temperatures and strong radiation, which make contact measurements of thermal or fluid parameters in the weld pool difficult or even impossible.…”