# Development of a Virtual Reality-Based System for Simulating Welding Processes
## 3 Results and Discussions
### Simulation Results and Discussions
#### 3.3.2 Discussions  
With the simulation results, the system allowed us to describe correctly the welding profile and the weld size. To prove these functionalities, simulations of the fillet weld joint were carried out. Figure 19 shows the dimensions of these plates. The simulation was carried out with the plate thickness changed as shown in Table 4. In comparison with the required results for the fillet weld joint [45; 46], the simulated filled weld profiles were correct. The difference in the weld sizes between the standard dimensions and the simulated dimensions generated by the developed virtual reality-based system was acceptable with errors of less than 9% for all the experiment cases. Figure 19: Dimensions of the plates for simulating the fillet weld joint. Figure 18: Simulation of the TIG welding process. With the target to help the user carry out the real welding process with better-quality joints by performing smoother welding with fewer mistakes, less inquiry time, and fewer hints [1,11,47], the functionality of the developed system was satisfied in comparison with the reported systems [1,11,47] and the commercial systems, such as OcuWeld [36] and VRTEX 360 [16,48]. These systems provide a real-time welding processes and realistic welding practice allowing for the interaction of the user with the welding components as in the real world. However, these systems also have some differences in the functionality as well as the technologies applied for implementation. Some similarities and differences of these systems are shown in Table 5 and are explained as follows:  
* Functionality: With some of the reported systems in the literature, these systems enable to simulate only one kind of welding process, such as SMAW (or MMAW--manual metal arc welding) [1,47] and MIG (or GMAW--gas metal arc welding) [11,13,14]. Some of the commercial systems enable to simulate more kinds of welding processes, such as the SMAW, MIG, and TIG welding processes [16,36,48]. With the objective of developing a VR-based system for education, more kinds of welding processes are necessary. So, we proposed the VR-based system that enables to simulate three welding processes: SMAW, MIG, and TIG. * Tracking the welding torch position: This is one important module for the development of the VR system. Currently, there are some devices applied, such as using cameras [13,14,16,36,48], Vive trackers [47], sensors [1], or both cameras and sensors [11]. With the camera for the tracking module and for processing data, an algorithm for processing the image data was used. With sensors for the tracking module and for processing data, an algorithm for processing the analog signals was used. In this research, the IR transmitters and IR sensors were used for tracking the welding torch position. The algorithm for processing the analog signals was proposed. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Required Results** [45,46] & **Simulated Results** \\ \hline
**Acceptable Fillet Weld Profiles** & & \\ \hline
**Plate Thickness (mm)** & **Weld Size L (mm)** & **Plate Thickness (mm)** & **Weld Size L (mm)** \\ \hline
3 & 3.5 & 3 & 3.8 \\ \hline
4 & 4.0 & 4 & 4.3 \\ \hline
5 & 4.5 & 5 & 4.8 \\ \hline
6 & 5.0 & 6 & 5.2 \\ \hline
8 & 6.0 & 8 & 6.4 \\ \hline
10 & 7.0 & 10 & 7.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparison of the required results and simulated results. Virtual reality module: For programming the virtual reality environment, some platforms and software were used, such as VB.net 2010 [1], Vive input Utility, and SRWorks software development kit [47]. In this research, the Unity3D platform and C# language were used; the PsoCreator was used for programming the connection of the VR module with the other modules. Visualization in 3D and processing of the user interactions in real time: This is a mandatory requirement of the VR system. So, all the VR systems (the reported systems and the commercial systems) have this functionality.