Exploiting Augmented Reality to Enhance Piping and Instrumentation Diagrams for Information Retrieval Tasks in Industry 4.0 Maintenance

In this work, we present an Augmented Reality (AR) application for handheld devices that support operators in information retrieval tasks in maintenance procedures in the context of Industry 4.0. Indeed, using AR allows the integration of knowledge-based information, traditionally used by operators and mainly provided in the form of technical drawings, and data available from sensors on the equipment. This approach is suggested by companies, especially Small and Medium-sized Enterprises, that want a gradual introduction of Industry 4.0 technologies within their established practices. We implemented a prototype of the application for the case study of a milling plant. The application augments on a Piping and Instrumentation Diagram (P&ID) of the plant some virtual interactive graphics (hotspots) referenced to specific components drawn. Component data are retrieved, through a user interface, directly from the factory database and displayed on the screen. We evaluated the application through a user study aimed at comparing the AR application with the current practice, based on paper documentation, for an information retrieval task within a maintenance procedure. Results of the study revealed that AR is effective for this task in terms of task time reduction and usability. The AR application was tested both with a tablet and a smartphone, but results revealed that using tablet does not improve user performance in terms of task time, error rate, and usability.