Point cloud classification and part segmentation of steel structure elements

Abstract The classification and part segmentation of point clouds have gained significant attention in the field of artificial intelligence (AI), especially in the construction industry. However, addressing the dataset directly in AI models remains a challenge, as most existing methods are not well-suited for processing point cloud data. PointNet has emerged as an AI architecture algorithm. It transforms individual points independently to learn local and global features. This research aims to develop a comprehensive framework for classification and part segmentation for point clouds of steel structure elements. The framework enhances the accuracy of the PointNet algorithm, and it consists of three stages: (1) dataset creation; (2) model classification; and (3) part segmentation. First, the dataset creation procedure encompasses modeling steel columns, beams, and braces using Autodesk Revit software. For the classification dataset, a dataset comprising 580 columns and 920 beams is obtained. In the part segmentation dataset, five categories of steel braced frame elements are generated, yielding a total of 21,870 elements for braced frame structures. Several point cloud experiments have been applied, including adjusting the number of points in the point cloud, altering the batch size, and fine-tuning the number of epochs. These experimental settings were systematically investigated to identify the optimal combination that yields the highest (AI) model accuracy. PointNet model achieved 100% accuracy across all classification experiments, while part segmentation experiments reached up to 97.10% accuracy, with a mean intersection over union (MIOU) of 93.70%. The comprehensive analysis of the point cloud dataset is applied on an actual case study to demonstrate the practical features of the proposed research.