Evaluation of SLAM technology in 3D data acquisition and implementation for HBIM applications

This study analyzes a SCAN-to-BIM workflow for the documentation of historic structures from survey data acquired by 3D laser scanning technology, specifically through Simultaneous Localization and Mapping technology (SLAM). The chosen case study is the Engineering Faculty of the University of Bologna, a historic building of rationalist architecture. The Geomatic group of University of Bologna tested the SLAM X120GO 3D laser scanner for data acquisition due to its portability, speed, and affordability, even though it is less precise than traditional instruments like accurate 3D laser scanners for static surveys (an example is the Leica RTC360 used in this experience as a reference). The main objective of the study was to assess the quality and precision of point clouds produced using SLAM technology. To accomplish this, the data generated by SLAM technology was compared against the reference data of a high quality 3D laser scanner. The findings suggest that while the point cloud obtained by the 3D laser scanner RTC360 is relatively more accurate than the SLAM-generated point cloud obtained by the X120GO, the accuracy and quality of point clouds produced by SLAM technology is generally acceptable for many applications. Autodesk Revit was then used for the Scan-to-BIM process to generate a BIM 3D model. In the final phase, cloud-to-mesh distance calculations were performed on the 3D model and the point cloud. In the context of HBIM documentation and 3D geometric restitution, the SLAM X120GO 3D laser scanner has proven to be a reliable device for data acquisition and surveying.