Vision-Based Quality Assessment of Prefabricated Components Using Images and Camera Poses

In modular construction, poor quality assurance and quality control (QA/QC) at offsite facilities can lead to serious cost escalations and delays. Offsite components that are not properly inspected will lead to incompatibility issues on job site during assemblies, which will lead to re-fabrication and re-shipping. This added lead time can easily affect the critical path. There have been research efforts to perform a visual inspection (although not specific to modular construction) using high precision sensors (i.e., laser scanners) and image-based 3D reconstruction. The former solution can be an expensive solution for smaller firms. The latter solution results in inconsistent results because it results in relatively noisy data. This paper attempts to address this limitation by combining leveraging camera poses from image-based 3D reconstruction and their images to select boundaries to be inspected. The proposed method is validated through a case study. A high precision mobile laser scanner was used for collecting the ground truth. The results demonstrate the effectiveness of the proposed method.