# Automated Fillet Weld Inspection Based on Deep Learning from 2D Images
## 2 Materials and Methods
### Preparation of Fillet Weld Test Piece  
To conduct a visual inspection aligned with weld characteristics, the recommendations and suggestions that appear in the ISO 15792-3:2011 [36] standard were taken into account. The standard, entitled \"Classification testing of positional capacity and root penetration of welding consumables in a fillet weld\", contains a series of suggestions necessary to be able to carry out an evaluation of the fillet weld in an appropriate manner.  
The standard goes on to address general requirements and the type of metal to be used in the weld, as well as the use of different welding wires and their testing. It also covers the material and the thickness that should be used for this type of weld, as discussed in Section 2.1 according to the document of standard, the citation is as follows [36].  
With regard to the preparation of the piece for welding and subsequent visual inspection, the standard establishes the following sections:  
* Prior to the assembly process, the component must be placed in an L-shape, with two plates of the designated metal forming a 90\({}^{\circ}\) angle. This configuration is to be achieved by using a web and a flange, with dimensions of these components complying with those stipulated in section 5.1 of the electrode classification standard [37].
* The subsequent essay will examine the position and conditions of welding. In this instance, the recommendations of the ISO 6947 [38] standard were adhered to withregard to electrode temperature and single-pass weld deposit. It is recommended that the reader consult Section 5.2 of the standard document ISO 15792-3:2011 [36].
* In order to comply with Section 5.3 of the standard document ISO 15792-3:2011 [36], welding speed recommendations were adhered to in accordance with the consumable used.
* It was determined that welding of the second side was not a prerequisite, thus rendering point 5.4 of the standard document ISO 15792-3:2011 [36] superfluous.  
In accordance with the established protocol, the sections pertaining to the examination of the test piece (Section 6) of the document ISO 15792-3:2011 [36] were analyzed. The decisions and actions undertaken in this context are outlined below:  
* In relation to the dimensions of the weld throat thickness, the robotic arm's welding parameters were utilized as the reference point. Subsequent to this, a measurement of the throat thickness was conducted, exhibiting a certain degree of flexibility with respect to the standard specifications. This resulted in a range of \(\pm\)10-15% for the measurement data.
* In order to comply with the measurements and requirements established in Section 6.2 of the standard document ISO 15792-3:2011 [36], the parameters were established in the robotic arm that was used to perform the welding with maximum precision. The welding beads were then measured, as well as the throat thickness. A convex fillet weld was established.
* It is evident that Section 6.2 of the standard has not been given due consideration, as it was understood that it had already been incorporated into prior preparations in other sections.  
Subsequent to the fabrication of the welding beads, the following inspections and measurements were conducted:  
* Visual inspection of defects and correct welds.
* Measurement of fillet leg lengths.
* Visualization of the correct convexity of the fillet.
* Verification of the throat, as previously indicated to the welding robot in the parameters.