A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing  

作　　者：Bao-Ri Zhang Yong-Hua Shi 

机构地区：[1]Bionic Robot Research Department,Ji Hua Laboratory,Foshan,528200,Guangdong,People’s Republic of China [2]Guangdong Provincial Engineering Research Center for Special Welding Technology and Equipment,School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou,510640,People’s Republic of China

出　　处：《Advances in Manufacturing》2024年第2期335-348,共14页先进制造进展（英文版）

基　　金：support provided by the China Scholarship Council and Basic and Applied Basic Research Foundation of Guangdong Province(Grant No.2022A1515110733).

摘　　要：The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive manufacturing.To obtain a high deposition accuracy,it is essential to maintain a stable weld pool size.In this study,a novel passive visual method is proposed to measure the weld pool length.Using the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a camera.It also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry changes.This algorithm can also be applied to materials with different solidification characteristics.Calibration was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the algorithm.Additionally,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关 键 词：Plasma arc additive manufacturing(PAAM) Weld pool geometry Gradient analysis Real-time detection 

分 类 号：O53[理学—等离子体物理]