Sensors for quality control in welding

Abstract

The classical inspection methods used for detecting and finding disturbances in welding process are based on direct measurement of its parameters as arc voltage, welding current, wire feed speed, etc. Using these inspection methods implies sensors insertion around the welding process and its presence could alter the metallic transference behavior and consequently an uneven quality as well as it can increase the production cost. For reducing these implications is necessary using a non intrusive inspection method. In this paper we will show nonintrusive methods to the weld quality inspection. These methods are based on sensor fusion, the extraction of global information coming from the interrelation data given by each sensor that, for example, sensing the spectroscopy radiation emission, the acoustic sensing of the electrical arc, the infrared emissions indicating the heat content of the weld. Finally, the fusion data will be applied to a statistical control for detecting and finding welding disturbances. The results will show that sensor fusion could be used as a tool to measure indirectly the weld quality in the GMAW process. Key-words: Quality Control in Welding, Spectroscopy, Acoustic sensing, Infrared emission, Sensor fusion. Resumo: Os métodos clássicos de inspeção utilizados para detectar e encontrar perturbações nos processos de soldagem são baseados comumente na medição direta de seus parâmetros como da tensão do arco, corrente de soldagem, velocidade de alimentação, etc. Usando esses métodos de inspeção implica inserção dos sensores em todo o processo de soldagem e sua presença poderia alterar o comportamento, por exemplo, da transferência metálica e, consequentemente, uma qualidade irregular da junta soldada, bem como provocaria o aumento do custo de produção. Para reduzir essas implicações é necessário usar um método de inspeção não intrusiva.

Welding Process Monitoring Applications and Industry 4.0

“…At the mid-level (Level 2 ), the system has the ability not only to detect the disturbances but also to identify their origin, highlighting the malfunction in the process. At the highest level (Level 3 ) the system is equipped with a feedback mechanism that intervenes in the process correcting the disturbances [6].…”

Measurement and estimation of the weld bead geometry in arc welding processes: the last 50 years of development

“…The use of magnitudes obtained by several sensors or measuring systems and compiled to obtain a value (or values) that describe the static or dynamic behaviour of processes have been popularized in the scientific community with the expressions ''sensor fusion'' or ''fusion sensory data'' [98,125,126].…”

Online Measurements in Welding Processes

“…The use of nondestructive tests and defect repair are slow processes. To avoid this, online monitoring and control of the welding process can favor the correction and reduction of defects before the solidification of the melted/fused metal, reducing the production time and cost [2].…”