# Design of a Digital Twin Training Centre for an Industrial Robot Arm
## 6 Testing the Effectiveness of Training Using the Virtual Program  
A test was conducted with volunteers to determine the effectiveness of the program's teaching. Students who were never exposed to robot programming in their previous studies have been used to test the software's impact on education.  
The digital twin will be used by various students from the University of Debrecen, Faculty of Engineering. Considering this, it was essential to find volunteers from different groups of students. Overall, 40% of the participants were female, and 60% were male. The age of the participants was between 19 and 25. The students were from the following courses: mechatronics engineering, mechanical engineering, and technical management. Half of the participants were Hungarian students, and the other half of the students came from Asia and Africa, learning English courses.  
The ten students who agreed to participate in the study were divided into two groups of five. The first group, team A, was given the opportunity to study the cyber space created in Unreal Engine 4, while team B was given the documents used in their education so far. After at least a half hour of preparation, each student was assigned a complex robot control task in physical space on a KUKA KRS industrial robot. A top view of the two geometric shapes is shown in Figure 18.  
Path training on a sample LIN part using CIRC motion types was required for the task. The time it took the students to complete the task was carefully planned using stopwatches, beginning when they received the Teach Pendant and ending when the robot returned to its home position. At any given time, there was only one student, one supervisor, and one timekeeper in the Robot laboratory. The two tasks, LIN-Triangle and CIRC -Circle, are performed on the sample part shown in Figure 19.  
The results are presented in Tables 1 and 2.  
Figure 17: Robot control in cyber space.  
Figure 19: Task in virtual and physical form.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{3}{c}{**A Team-Blue**} \\ \hline  & **LIN-Triangle** & **CIRC-Circle** & **Total Time** \\ \hline
1 & 6:18 & 12:27 & 18:45 \\
2 & 8:45 & 10:16 & 19:01 \\
3 & 4:35 & 9:56 & 14:31 \\
4 & 9:27 & 15:37 & 25:04 \\
5 & 7:03 & 8:46 & 15:49 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Team “A” results depending on the use of the program.  
Figure 18: Standard path training tool.  
After completing the exercise, the student received feedback via Google forms [59], after selecting whether they used 'A' software assistance and 'B' traditional teaching aids to prepare before filling out the answers. Responses to the other questions were scaled from 1 to 5 (1--strongly disagree, 5--strongly agree).  
To get feedback on the user experience, 10 questions on the system usability scale (SUS) were asked [60]. The feedback shows that the value fell between 3.6-5.0, which means they were satisfied with the program. This indicates that users could use it for training purposes. The results are presented in Table 3.  
According to the tables, those who had access to the software were able to complete the two types of tasks more quickly. They were also better prepared and more knowledgeable about how to use the Teach Pendant and robot. Those who had been prepared with traditional materials found it much more difficult to understand how and on what basis the tasks should be solved.  
The responses to the Google forms questions indicate that there is a need to expand the educational material using the software. This not only improves efficiency, but it also allows for better distribution of development in other labs, which really is important because lab capacity is limited. However, if the people involved in the training learn how to operate the robot sooner, capacity in the laboratory will be freed up sooner.