Fiber Bragg Grating sensors for on-line welding diagnostics

In this work Fiber Bragg Grating transducers (FBGs) are used to perform an on-line monitoring of an arc-welding process by means of the combined temperature and strain profile. The main goal of this approach is to establish a correlation between the appearance of defects in the seams and the response offered by the FBGs, exploring the optimal disposition of the FBGs in terms of their sensitivity to weld defects. The proposed solution will be explored by means of welding tests and a comparison with a plasma spectroscopic analysis.This work has been supported by the project TEC2010-20224-C02-02 and grant AP2009-1403. Authors would also like to thank Roberto Perez Sierra for his valuable help during the FBGs fabrication process

Spectroscopic optical sensors for welding diagnostics

A review of solutions involving plasma optical spectroscopy applied to on-line welding quality monitoring is presented in this paper. After a brief introduction to welding processes and their requirements in terms of quality monitoring, different proposals for on-line monitoring will be addressed. The basics of welding monitoring via plasma spectroscopy in terms of light capture and hardware and processing requirements will be also introduced, and different approaches will be presented. Finally, a variety of examples regarding field trials in different sectors will be also discussed

Advances in Plasma Arc Welding: A Review

The nature of welding in the aeronautical industry is characterized by low unit production, high unit cost, extreme reliability and severe service conditions. These characteristics point towards more expensive and more concentrated heat sources such as plasma arc, laser beam and electron beam welding as the processes of choice for welding of critical components. Among various precision welding processes, Plasma Arc welding has gained importance in small and medium scale industries manufacturing bellows , diaphragms etc because of less expensive and easy to operate. This paper reviews the works on Plasma Arc welding and associated phenomena such as Micro Plasma Arc Welding, Variable Polarity Plasma Arc welding and Keyhole Plasma Arc Welding. The review covers works carried out by various researchers on various metals using different modes of plasma arc

Hyperspectral imaging sustains production-process competitiveness

A newly developed imaging system aids companies in the agri-food and industrial sectors to achieve high-speed online inspection and enhanced quality control

Colorimetric analysis for on-line arc-welding diagnostics by means of plasma optical spectroscopy

In this paper an analysis on the suitability of employing a colorimetric analysis of the acquired plasma spectra to perform on-line arc-welding quality monitoring will be discussed. Different colorimetric parameters like the color temperature or the parameters associated with the hue, saturation, luminance color space will be evaluated in comparison with the standard approach based on the estimation of the plasma electronic temperature. This approach does not require the identification of the emission lines involved in the analysis, thus giving rise to a more efficient solution in terms of computational efficiency, and avoiding unambiguous identifications that may give rise to incorrect results. In particular, experimental tests performed with a tungsten inert gas arc-welding process will show the feasibility of using the proposed solution and its ability to perform an online detection of different welding perturbations.This work has been supported by the project TEC2013-47264-C2-1-R

Hyperspectral imaging for diagnosis and quality control in agri-food and industrial sectors

Optical spectroscopy has been utilized in various fields of science, industry and medicine, since each substance is discernible from all others by its spectral properties. However, optical spectroscopy traditionally generates information on the bulk properties of the whole sample, and mainly in the agri-food industry some product properties result from the heterogeneity in its composition. This monitoring is considerably more challenging and can be successfully achieved by the so-called hyperspectral imaging technology, which allows the simultaneous determination of the optical spectrum and the spatial location of an object in a surface. In addition, it is a nonintrusive and non-contact technique which gives rise to a great potential for industrial applications and it does not require any particular preparation of the samples, which is a primary concern in food monitoring. This work illustrates an overview of approaches based on this technology to address different problems in agri-food and industrial sectors. The hyperspectral system was originally designed and tested for raw material on-line discrimination, which is a key factor in the input stages of many industrial sectors. The combination of the acquisition of the spectral information across transversal lines while materials are being transported on a conveyor belt, and appropriate image analyses have been successfully validated in the tobacco industry. Lastly, the use of imaging spectroscopy applied to online welding quality monitoring is discussed and compared with traditional spectroscopic approaches in this regard

Application Of Defect Detection In Gluing Line Using Shape-Based Matching Approach

This paper investigates various approaches for automated inspection of gluing process using shape-based matching application. A new supervised defect detection approach to detect gap defect, bumper defect and bubble defect in gluing application is proposed. The creation of region of interest for important region of the object is further explained. The Correlation algorithm to determine better image processing result using template matching techniques is also proposed. This technique does not only reduce execution time, but also produce high accuracy in defect detection rate. The recognition efficiency will achieve more than 95% with defect’s data for further process

Welding process monitoring applications and industry 4.0

With the fourth industrial revolution in progress, traditional manufacturing processes are being transformed. Fusion welding is no exception from this transformation. The centuries-old manual craft is being reshaped by cyber-physical systems, turning into a digitized process governed by industrial informatics. By implementing process monitoring in welding applications invaluable data are collected that can be utilized in the new, futuristic smart factories of Industry 4.0. In this article two purposes are being served. The first is to present the status quo alongside the future trends of welding process monitoring on industrial implementation. The second is to present the results of an ongoing investigation of robotic Gas Tungsten Arc Welding (GTAW) monitoring for defect detection and characterization. Deviations from the optimal values in three welding conditions (surface integrity, shielding gas flow rate and surface contamination) were introduced during stainless steel 316L beads-on-plates welding. Acquired data during the welding process were used to extract features in order to identify correlations between the disturbances and the monitored signals