Collective AR-assisted assembly of interlocking structures

Research on mobile Augmented Reality (AR) technologies has proven many potentials and benefits for assisting craftspeople in various building applications within the AEC domain. However, little research has been done on the use of multi-user mobile AR systems coordinating several people at the same time. This paper examines the potentials of a collective construction process enabled by AR technology that distributes and guides manual assembly tasks for multi-user participation. For this purpose, a custom mobile AR app is developed that uses cloud services and allows multiple people to participate in the construction and be coordinated with each other at the same time. In the proposed setup, digital building instructions for the stepwise assembly of a physical building structure can be retrieved by multiple users via the app. The app positions these building instructions in 3D space, visually superimposed on the building site, where the building structure is being assembled. Methods are proposed for synchronizing the construction progress via user-specific AR content visualization over the app's user interface (UI). Based on the principle of topologically interlocking structures, the material system developed for this research offers several form-fitting connections with one modular wooden component without the need for mechanical fasteners for their assembly. This principle enables the manual implementation of various complex building structures at full architectural scale, which are reconfigurable and fully disassemblable. The proposed methods were experimentally validated in a 1:1 scale demonstrator. A pavilion was assembled collectively by students and researchers over two days, and the UI was evaluated through a qualitative user study. As an outlook, the paper discusses the potential of such AR systems to make digitally-driven construction processes more tangible and accessible to laypersons and unskilled people and thus encourage community participation.