Model-based planning of complex 3D laser scanning campaigns for bridge digitisation

Large, complex structures like bridges are essential infrastructure, expensive to design, construct, monitor, and maintain. The digitisation of bridges has advanced in areas such as structural health monitoring, maintenance, load simulation, and bridge information modelling. 3D laser scanning captures these structures in digital space, and recent advancements have improved the creation of realistic digital twins. These technological improvements necessitate an optimised planning process for scanning campaigns, aiming to maximise coverage efficiently and reduce reliance on subjective human expertise. This paper introduces a model-based approach for planning-for-scanning (P4S), which devises efficient bridge scanning strategies using single or multiple laser scanners. Utilising existing bridge information, such as architectural plans and scanner properties, the algorithm estimates positions and trajectories to capture high-quality point clouds. Tested on the Gaskugel Bridge over the Dreisam River in Freiburg, Germany, the approach demonstrated enhanced data quality and efficiency compared to traditional methods relying on human expertise.