TY - GEN
T1 - Real-time measurement of the weld pool surface in GTAW process
AU - Zhang, Wei Jie
AU - Zhang, Yu Ming
PY - 2013
Y1 - 2013
N2 - This study aims at real-time measurement /reconstruction of the specular three-dimensional (3D) weld pool surface under strong arc in gas tungsten arc welding (GTAW) using an innovative machine vision system. A dot-matrix laser pattern is projected on the specular weld pool surface. Its reflection from the specular surface is intercepted at a distance from the arc by a diffuse plane. The intercepted laser illuminates this plane producing an image showing the reflection pattern. The deformation of this reflection pattern from the projected pattern can be used to derive the 3D shape of the reflection surface, i.e., the specular weld pool surface. The image of the reflection laser pattern is captured by a separate camera. To measure and reconstruct the weld pool surface in real-time, a fast solution is needed to derive/reconstruct the weld pool surface from the extracted laser reflection pattern and the known incident laser pattern. Based on careful analysis, the underlying reconstruction problem is formulated mathematically. An analytic solution has been proposed to solve this formulated problem resulting in that the surface reconstructed in average 3.04 ms such that a weld pool surface can be measured/reconstructed at 30Hz from image acquisition, processing to surface reconstruction. A real-time system is thus established to measure and reconstruct the weld pool surface in GTAW in real-time during welding. Simulations and real-time experiments verified the effectiveness of the established system.
AB - This study aims at real-time measurement /reconstruction of the specular three-dimensional (3D) weld pool surface under strong arc in gas tungsten arc welding (GTAW) using an innovative machine vision system. A dot-matrix laser pattern is projected on the specular weld pool surface. Its reflection from the specular surface is intercepted at a distance from the arc by a diffuse plane. The intercepted laser illuminates this plane producing an image showing the reflection pattern. The deformation of this reflection pattern from the projected pattern can be used to derive the 3D shape of the reflection surface, i.e., the specular weld pool surface. The image of the reflection laser pattern is captured by a separate camera. To measure and reconstruct the weld pool surface in real-time, a fast solution is needed to derive/reconstruct the weld pool surface from the extracted laser reflection pattern and the known incident laser pattern. Based on careful analysis, the underlying reconstruction problem is formulated mathematically. An analytic solution has been proposed to solve this formulated problem resulting in that the surface reconstructed in average 3.04 ms such that a weld pool surface can be measured/reconstructed at 30Hz from image acquisition, processing to surface reconstruction. A real-time system is thus established to measure and reconstruct the weld pool surface in GTAW in real-time during welding. Simulations and real-time experiments verified the effectiveness of the established system.
KW - Gas tungsten arc welding (GTAW)
KW - Monitoring
KW - Reconstruction
KW - Three-dimensional weld pool surface
UR - http://www.scopus.com/inward/record.url?scp=84880694535&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84880694535&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84880694535
SN - 9781627089982
T3 - ASM Proceedings of the International Conference: Trends in Welding Research
SP - 1057
EP - 1063
BT - Trends in Welding Research - Proceedings of the 9th International Conference
T2 - 9th International Conference on Trends in Welding Research
Y2 - 4 June 2012 through 8 June 2012
ER -