Terrestrial laser scanning assisted dimensional quality assessment for space frame components

Space frame components (SFCs), mainly spherical joints and cylindrical tubes, are characterized by their large number. The dimensional quality assessment (DQA) of SFCs relies on manual measurements, which are subjective and inefficient. Since the surface of SFCs is mainly curved, many DQA items are hardly achieved by manual measurements. As the terrestrial laser scanning (TLS) can record accurate point cloud data of SFCs, it is widely used in the construction industry for DQA. This study proposes an automated method for DQA on SFCs based on TLS, including the component recognition, geometric parameter estimation, and DQA. A feature-based method is applied for component recognition. The geometric parameter estimation algorithms for spherical joints and cylindrical tubes are proposed. The effectiveness of the proposed method is verified by comparing the proposed algorithms with other algorithms and by conducting the validation experiment on 13 spherical joints and 33 cylindrical tubes.