Automating surface flatness control using terrestrial laser scanning and building information models

• We propose a surface flatness control system integrating laser scanning and BIM.
• The system automatically applies the Straightedge and F-Numbers methods.
• Experiments are conducted using real-life data.
• The system compares favorably with traditional labor-intensive methods.
• A novel Straightedge generation method achieves more reliable and complete results.

Current practice in the control of surface flatness requires a significant amount of time and labor, and delivers results based on few sample measurements. Developments of Terrestrial Laser Scanning (TLS) and Building Information Modeling (BIM) offer great opportunities to achieve a leap forward in the efficiency and completeness of dimensional control operations. This paper presents an approach that demonstrates the value of this integration for surface flatness control. The approach employs the Scan-vs-BIM principle of Bosché and Haas (2008) to segment TLS point clouds acquired on-site, by matching each point to the corresponding object in the BIM model. The novel approach then automatically applies two different standard flatness control techniques, Straightedge and F-Numbers, to the TLS points associated to each floor, and concludes with regard to their compliance with given tolerances. The approach is tested and validated using data from two actual concrete slabs. Results confirm the suitability of using TLS for conducting standard dimensional controls, and validate the performance of our system when compared to traditional measurement methods (in terms of both quality and efficiency). Furthermore, a novel straightedge generation method is proposed and demonstrated that enables more complete and homogeneous analysis of floor flatness for insignificant additional processing times.