# Effect of Augmented Reality Support on Quality Inspection of Welded Structures
## 2 Related Work  
This section presents the results of the theoretical research related to the topic. With the new industrial revolution, production systems are evolving, and so should inspection systems. The development of new technologies and the transformation of the industrial environment result in increasing efficiency, higher quality, and reduced costs [21; 22; 23]. Technological research focuses on adapting quality control to the new industrial revolution by providing faster, more accurate and reliable decision support systems [24]. To support the flexibility of inspectors, it is necessary to increase the availability of information and to link relevant quality characteristics as a basis for product quality assessment. The rising availability of holistic data, such as product and process specifications, historical measurement data, and production efficiency, should be used not only to assess geometric characteristics but also to strategically manage the manufacturing and inspection process in a closed loop [25; 26]. This technological transformation will have a significant effect on the nature of work in the industrial environment, as the new working environment has a direct impact on the operator by creating new interactions between people and machines, as well as between the digital and physical worlds [23; 27; 28; 29]. In this perspective, the worker becomes a skilled smart operator whose physical, sensory, and cognitive skills can be enhanced and complemented by new systems and tools equipped with advanced technologies [23; 30; 31]. According to [PERSON]. [32; 33], AR is one of the most promising techniques for enhancing the transfer of information between the digital and physical worlds. With its ability to integrate virtual information into the user's perception of the real world, AR can support operators directly in their workplace. It can support operators in real time during manual operations and enable them to reduce the risk of human error caused by dependence on the operator's memory, printed workflows, or printed technical drawings that must be interpreted in advance by the supervisor or technologist [32; 33]. AR can improve operators' skills by providing relevant data in the users' field of view. Thus, it can play an important role in various industrial applications to support operators, including the following:  
* Assembly [34; 35; 36; 37];
* Maintenance [38; 39; 40; 41; 42];
* Training [43; 44; 45; 46; 47];
* Monitoring and quality assessment [48; 49]. The link between inspection models and the Industry 4.0 concept was first identified by [PERSON] et al. [50]. The authors have identified five main development areas of quality inspection that must respond to the trends and challenges of the fourth industrial revolution. The first three are mainly related to technological advances. The last two also involve a change in the methodological approach. These challenges include the following:  
* Speed;
* Accuracy;
* Reliability;
* Flexibility;
* Holistic approach. The authors evaluate the use of information systems capabilities, specifically AR, as part of the Industry 4.0 concept as a technological opportunity that has the potential to increase process efficiency and reduce errors by supporting the operator's attention to the activity being performed by providing visual support [16; 51]. By using AR, the operator can focus on the task at hand while receiving visual feedback. By displaying relevant information, AR tools can support workers in less routine tasks or relatively complex operations [31; 52]. Augmented reality allows for the display of digital information in a real situation. This presents the potential for quality control processes by, for example, providing instructions or other related data. It can also lead to reduced costs, errors, and inspection time [53; 54].