Creating asynchronous Augmented Reality Instructions through a Virtual Reality Framework

Augmented Reality (AR) has proven, in the last years, its value to support professionals while performing tasks with some complexity helping reducing times and errors. Despite recent advances, one significant limitation to the adoption of AR instructions in real applications is related to the authoring process: the creation of AR instructions is an expensive, time-consuming, and task-specific process that is typically performed by experts in computer science and/or 3D modeling. In this work, we propose a framework that uses Virtual Reality (VR) to simplify the authoring process. A user, immersed in a virtual replica of the real space creates, in VR, spatial non verbal instructions and annotations that are then exported in an editable format. The instructions are then interpreted asynchronously by an AR-HMD system to guide a local user during an intervention, such as a maintenance route, in the real environment.The creation of the instructions in VR presents several advantages: users do not need any specific technological knowledge, after the initial modeling there is no need to further access the environment (unless due to significant geometric changes) allowing to perform easily updates even remotely. A user study with 10 participants was conducted to verify the ability of the users to follow the AR guiding instructions created in the VR environment when compared to a traditional pen and papers setting. For the use case, we consider a fire safety control route where users must verify fire protection devices and warning signals in a given building area. The AR system using the created annotations showed better performance than the traditional pen and paper method for task failure rate but worse for total time. Nonetheless, without text insertion tasks, the system also performed better for total time. Users agreed that the system could be used for other tasks, such as assembly/disassembly and that the available annotations were sufficient for any task.