Machine Learning and Deep Learning for the Built Heritage Analysis: Laser Scanning and UAV-Based Surveying Applications on a Complex Spatial Grid Structure

Abstract

The reconstruction of 3D geometries starting from reality-based data is challenging and time-consuming due to the difficulties involved in modeling existing structures and the complex nature of built heritage. This paper presents a methodological approach for the automated segmentation and classification of surveying outputs to improve the interpretation and building information modeling from laser scanning and photogrammetric data. The research focused on the surveying of reticular, space grid structures of the late 19th–20th–21st centuries, as part of our architectural heritage, which might require monitoring maintenance activities, and relied on artificial intelligence (machine learning and deep learning) for: (i) the classification of 3D architectural components at multiple levels of detail and (ii) automated masking in standard photogrammetric processing. Focusing on the case study of the grid structure in steel named La Vela in Bologna, the work raises many critical issues in space grid structures in terms of data accuracy, geometric and spatial complexity, semantic classification, and component recognition.

Analysis on Using 3D Scanning and BIM to Reduce the Physical and Non-Physical Construction Waste for Sustainable Fireproofing of Steel Trusses

“…This enhances overall project safety by minimizing the risks associated with on-site data collection, particularly in complex construction environments [7]. However, laser scanning also presents some challenges in terms of data acquisition due to the complex configuration of the steel truss, which results in shadowed areas where the laser beam cannot reach [20]. This problem can be overcome by using multiple terrestrial stations or positioning them according to this limitation by using UAVs (Unmanned Aerial Vehicles) equipped with scanning instruments to complement the data acquired by terrestrial scanning [21], or by collecting data using conventional techniques (manual surveying and photographs) when possible.…”