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

2012 ◽  
Vol 236-237 ◽  
pp. 469-473 ◽  
Author(s):  
Ya Dong Zhang ◽  
Zhi Min Liang ◽  
Dian Long Wang ◽  
Jun Wang
Keyword(s):  
Weld Pool ◽  
Stereo Matching ◽  
Stereo Image ◽  
Image Pair ◽  
Camera System ◽  
3D Shape ◽  
Pool Surface ◽  
Current Period ◽  
Scan Line ◽  
Weld Pool Surface

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

scholarly journals 3D Reconstruction Algorithm of Weld Pool Surface Based on Computer Vision Technology

2015 ◽  
Vol 9 (1) ◽  
pp. 820-825
Author(s):  
Zhen-Hai Mu
Keyword(s):  
3D Reconstruction ◽  
Weld Pool ◽  
Stereo Matching ◽  
Vision System ◽  
Reconstruction Algorithm ◽  
Welding Parameters ◽  
Matching Algorithm ◽  
Pool Surface ◽  
Matching Cost ◽  
Weld Pool Surface

As is well known that sensing and measuring the weld pool surface is very important to design intelligent welding machines which is able to imitate a skilled human welder who can choose suitable welding parameters. Therefore, in this paper, we focused on the problem of weld pool surface 3D reconstruction, which is a key issue in intelligent welding machines development. Firstly, the framework of the weld pool surface 3D reconstruction system is described. The weld pool surface 3D reconstruction system uses a single camera stereo vision system to extract original data from weld pool, and then the left and right images are collected. Afterward, we utilize Pixel difference square and matching algorithm and Stereo matching algorithm to process images. Next, the 3D reconstruction of weld pool surface is constructed using the point cloud data. Secondly, stereo matching based weld pool surface 3D reconstruction algorithm is illustrated. In this algorithm, the matching cost function is computed through the Markov random field, and then the weighted matching cost is calculated via the guided filter. Thirdly, to test the performance of our proposed algorithm, we develop an experimental platform to measure weld pool width, length, convexity and the previous inputs based on a linear model predictive controller. Experimental results demonstrate that the proposed 3D reconstruction algorithm of weld pool surface can achieve high quality under both current disturbance and speed disturbance.

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

2009 ◽  
Vol 105 (12) ◽  
pp. 123104 ◽  
Author(s):  
C. X. Zhao ◽  
I. M. Richardson ◽  
S. Kenjeres ◽  
C. R. Kleijn ◽  
Z. Saldi
Keyword(s):  
Weld Pool ◽  
Stereo Vision ◽  
Particle Flow ◽  
Pool Surface ◽  
Weld Pool Surface

The oscillation of stationary weld pool surface in the GTA welding

2018 ◽  
Vol 256 ◽  
pp. 57-68 ◽  
Author(s):  
J.K. Huang ◽  
M.H. Yang ◽  
J.S. Chen ◽  
F.Q. Yang ◽  
Y.M. Zhang ◽  
...  
Keyword(s):  
Weld Pool ◽  
Gta Welding ◽  
Pool Surface ◽  
Weld Pool Surface

scholarly journals Influence of Pilot Gas Composition on Convective Pattern of Weld Pool Surface in Plasma Keyhole Arc Welding

2017 ◽  
Vol 35 (2) ◽  
pp. 98s-102s ◽  
Author(s):  
Van Anh Nguyen ◽  
Shinichi Tashiro ◽  
Bui Van Hanh ◽  
Manabu Tanaka
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Gas Composition ◽  
Pool Surface ◽  
Convective Pattern ◽  
Weld Pool Surface

scholarly journals Material Flow Behavior on Weld Pool Surface in Plasma Arc Welding Process Considering Dominant Driving Forces

2020 ◽  
Vol 10 (10) ◽  
pp. 3569 ◽  
Author(s):  
Manh Ngo Huu ◽  
Anh Nguyen Van ◽  
Tuan Nguyen Van ◽  
Dang Tran Hai ◽  
Thanh Nguyen Van ◽  
...  
Keyword(s):  
Weld Pool ◽  
Material Flow ◽  
Arc Welding ◽  
Shear Force ◽  
Driving Forces ◽  
Flow Behavior ◽  
Shielding Gas ◽  
Pool Surface ◽  
Marangoni Force ◽  
Weld Pool Surface

In this study, the effect of oxygen in the shielding gas on the material flow behavior of the weld pool surface was discussed to clarify the dominant driving weld pool force in keyhole plasma arc welding (KPAW). To address this issue, the convection flow on the top surface of weld pool was observed using a high-speed video camera. The temperature distribution on the surface along keyhole wall was measured using the two-color pyrometry method to confirm the Marangoni force activity on the weld pool. The results show that the inclination angle of the keyhole wall (keyhole shape) increased especially near the top surface due to the decrease in the surface tension of weld pool through surface oxidation when a shielding gas of Ar + 0.5% O2 was used. Due to the change in the keyhole shape, the upward and backward shear force compositions created a large inclination angle at the top surface of the keyhole. From the temperature measurement results, the Marangoni force was found to alter the direction when 0.5% O2 was mixed with the shielding gas. The shear force was found to be the strongest force among the four driving forces. The buoyant force and Lorentz force were very weak. The Marangoni force was stronger than the Lorentz force but was weaker than shear force. The interaction of shear force and Marangoni force controlled the behavior and speed of material flow on the weld pool surface. A strong upward and backward flow was observed in the case of mixture shielding gas, whereas a weak upward flow was observed for pure Ar. The heat transportation due to the weld pool convection significantly changed when only a small amount of oxygen was admixed in the shielding gas. The results can be applied to control the penetration ratio in KPAW.

Sign in / Sign up

Export Citation Format

Share Document