Towards Automatic Digital Documentation and Progress Reporting of Mechanical Construction Pipes using Smartphones

This manuscript presents a framework towards automated 3D digital documentation and progress reporting of mechanical pipes in building construction projects, using smartphones. New methods were proposed to determine the video frame rate required to achieve a desired image overlap; define metric scale for 3D reconstruction; extract pipes from point clouds; and classify pipes according to their planned bill of quantity radii. The effectiveness of the proposed methods in both laboratory (six pipes) and construction site (58 pipes) conditions was evaluated. It was observed that the proposed metric scale definition achieved sub-millimeter pipe radius estimation accuracy. Both laboratory and field experiments revealed that increasing the image overlap improved the pipe classification quality, radius, and length. Overall, using the proposed methods, it was possible to achieve pipe classification F-measure, radius estimation accuracy, and length estimation percent error of 96.4%, 5.4mm, and 5.0%, respectively, on construction sites using at least 95% image overlap.