Development and Usability Evaluation of Mobile Augmented Reality Contents for Railway Vehicle Maintenance Training: Air Compressor Case

Abstract

The air compressor of a railroad vehicle is an important equipment that produces compressed air used in braking systems. New visual interaction techniques were proposed and evaluated to develop effective augmented reality content for maintenance support and training of this device. To this end, modeling techniques capable of fast animation, storyboard production to support light maintenance, and visualization algorithms that implement fluid flow have been developed. In the case of air compressors using compressed air, 2D-3D line matching distance calculation algorithm and modified flow generation algorithm were proposed to implement fluid flow for visualization. If two algorithms are used at the same time, the educational effect can be enhanced by visualizing the air flow in the 3D object simultaneously on a 2D air pipe diagram. In addition, the use of flow generation algorithm alone can visualize fluid flow or quantity control, such as air discharge or lubricant supplementation. As a result of usability evaluation of 100 users of the developed air compressor augmented reality content, the system usability scale score was 76.65, which was good. Similarly, the user experience score using six questionnaires was very good with an average of 4.12. Therefore, it was found that this training content could be used very effectively for air compressor maintenance support and training at the site.