Combining Large-Scale 3D Metrology and Mixed Reality for Assembly Quality Control in Modular Construction

Abstract

The quality control (QC) of assembled modules is an essential process when constructing modular buildings such as hotels and hospitals. Defects that go undetected during module assembly may result in lost productivity in the form of unnecessary transportation, rework or project delays. QC has traditionally been performed using specialized tools and carried out a posteriori in an inspection station dedicated solely to this task. Nowadays, large-scale 3D metrology technology provides a more efficient alternative since it enables accurate measurements to be taken in situ. Additionally, mixed reality (MR) supports the immersive projection of information and guidance instructions. This paper introduces a proof of concept of a framework that combines industrial photogrammetry with the HoloLens 2 MR headset to assist with assembly and QC during the off-site construction phase of modular construction. Many tests were conducted in a laboratory and a factory setting to evaluate the system’s user-friendliness and possible challenges associated with its future implementation. The experiments conducted confirmed that combining 3D metrology with MR offers an interesting solution for integrating QC into the assembly process. However, further work is needed to enhance the measurement workflow and optimize the measurement system’s accuracy