# Augmented Reality-Based Framework Supporting Visual Inspection for Automotive Industry
## 4 Result and Validation  
As mentioned previously, during the vehicle inspection, the operator must check and correct the defects that occur along the production line. For that, a UI was designed, using Unity 3D, to display dynamically the list of errors and controls, which is shown in Figure 5.  
Figure 4: The software framework of the cognitive system. Additionally, markers stored in a cloud database using Vuforia SDK, identifying the vehicle, that need to be tracked are included in the AR application. In our scenario, the marker is presented as a QR code format given its sharpness and precision. As the main output of this study, the proposed system was built successfully into windows (see Figure 6) and Android (see Figures 7 and 8) platforms. For Android, which is our main target platform for the automotive industry requirement, the proposed system is saved in an application format of type *.APK. We have also built the AR application onto an AR head-mounted display (HMD), an Android-based platform, which is Vuzix M300 smart glass [33]. Considering its lightweight (140 g), the industry under study decided to execute the proposed system on the Vuzix M300 smart glasses. To verify the validity of the proposed AR system, we carried out several experiments. In order to do that, we referred to the base of criteria defined in [11] for AR system evaluation which are: reliability, responsiveness, and agility. We started by investigating the reliability by checking the conformity of data received from the IIoT platform. Global validation was performed within other entities that were responsible for IIoT platform conception. Experimental tests using the proposed AR system and the IIoT platform were concluded successfully. Indeed, the validation was realized in different phases. Firstly, the system specification and design were validated with the main customer, which is the automotive industry under study. Secondly, integration of the system within the rest of implemented modules for the automotive industry was successfully concluded regarding the correct data transmission and visualization. For responsiveness criteria, which denotes the ability to provide the augmented content the quickly as possible, we measured the time needed for our AR system to start. To display the tasks related to a vehicle, the AR system needed an average of around 1 s when the marker is placed in the field of view of the camera. This value may be considered low ensuring the responsiveness feature. Then, regarding agility, the software topology is developed in a way to support any device. In addition, the proposed AR system responds and provides accurately the 2D information  
Figure 5: A screenshot of our development environment (Unity), presenting the UI design where BDG/VIS, Estd, Localizacão, and Naturez represent respectively: Vehicle ID, defect type (Control/error), defect location in the vehicle, and defect description. To end up, it is essential to evaluate user acceptance considering the ergonomic aspect and work conditions. Ten people of two separate profiles (five researchers and five operators) were interrogated to evaluate the effectiveness of the AR system in such a manufacturing process. The reason for the low volume of users is highly linked to confidentially, as required by the industry under study. Tests are performed using five researchers within the same laboratory, and who are affected by the same project but with different research backgrounds to avoid the maximum risk of bias in the results. The selected researchers are two professors and three Ph.D. students associated with different tasks in the industry under study. As for the number of operators, we selected five random operators working on distinct shifts at the last inspection station where we implemented the system. Based on the questionnaire posed in [34] for an industrial Virtual Reality (VR) application evaluation, we proposed the following questionnaire for user experience analysis:  
1. Have you felt dizzy during or after the AR experience? 2.