SynchronizAR: Instant Synchronization for Spontaneous and Spatial Collaborations in Augmented Reality

We present SynchronizAR, an approach to spatially register multiple SLAM devices together without sharing maps or involving external tracking infrastructures. SynchronizAR employs a distance based indirect registration which resolves the transformations between the separate SLAM coordinate systems. We attach an Ultra-Wide Bandwidth~(UWB) based distance measurements module on each of the mobile AR devices which is capable of self-localization with respect to the environment. As users move on independent paths, we collect the positions of the AR devices in their local frames and the corresponding distance measurements. Based on the registration, we support to create a spontaneous collaborative AR environment to spatially coordinate users' interactions. We run both technical evaluation and user studies to investigate the registration accuracy and the usability towards spatial collaborations. Finally, we demonstrate various collaborative AR experience using SynchronizAR.