# Virtual Reality Training Application for the Condition-Based Maintenance of Induction Motors
## 2 Related Work  
### Virtual Reality Applications  
The development of VR-based environments represents a practical and effective solution for training new technicians. Thanks to this technology, a deeper understanding of the operation of the machinery involved in industrial processes can be achieved; in this regard, several investigations have reported the frequent use of non-immersive VR training systems. Certainly, the implementation of training VR tools for the instruction of new technicians is a promising alternative to simulate industrial processes, where the reduction of time, the analysis of different real scenarios without any risk, and the reduction of accidents are the main benefits of VR training in comparison with classical face-to-face training approaches [17]. Thus, there are several works that have reported the use of VR-based tools in the field to train new technicians in real cases referring to different applications. In this sense, a VR training system was reported in [18] to perform both the maintenance and operation of high-voltage overhead power lines where, in a real situation, the technicians are exposed to high-risk procedures and lethal accidents. Similarly, [19] presents the development of a VR-based training system that was designed for industrial operators to perform assembly tasks, in which workers are placed on assembly lines in accordance with their experience; additionally, trainee workers with basic experience can be trained with those assemblies that the expert workers have previously introduced in the system. The general purpose of these applications is to provide practical utility regarding a suitable work-force training for certifying new operators to work under dangerous and complex environments [20; 21].  
Over the last few years, several research works have explored the use of immersive virtual reality applications for training; thus, in [22], the development and implementation of a training environment using VR to improve technical skills in the maintenance of live-line power distribution networks is presented. This contribution is focused on improving technical skills in maintenance. It provides the trainer with a workforce training system suitable for instructing and certifying operators who will thus be more competent in tasks that involve complex and dangerous environments.  
Some examples are also found in virtual training tools for electrical engineering education. In [23], users have the possibility of comparing structural differences between different devices, assembling and disassembling the machines and testing them under extreme conditions. Some examples that present specifically designed solutions for the teaching of induction motors [24; 25] are used with head-mounted displays (HMDs) and controllers with only three degrees of freedom (3 DOF), such as the Oculus Go, with which users cannot interact with the equipment in a natural way. The use of virtual laboratories in virtual reality stands out against other methods, such as web or video content, due to its ability to provide spatial and embodied interactions that allow hands-on practice for novices. VR has proven itself to be an effective medium to improve knowledge acquisition, retention and self-efficacy, in addition to reducing the error rate when compared to other traditional training methods [26; 27].