Geometric assessment for fabrication of large hull pieces in shipbuilding

In this paper we propose a geometric assessment method in order to establish a theoretical foundation for the automation of fabricating curved steel plates through the line-heating process in shipbuilding. We focus on measurement, comparison and the measurement data process in the overall system which was developed at Seoul National University, Korea, Shin et al. [Shin JG, Ryu CH, Lee JH, Kim WD. A user-friendly, advanced line-heating automation for accurate plate fabrication. Journal of Ship Production 2003;19(1):8–15]. The measurement is performed using a scanning device, which provides the digitized geometric data of a curved plate. The measured data are then positioned against a design plate so that comparison between them is made to determine whether we have obtained the desired shape. If not, the data are approximated in BB-spline surface form and the approximated surface and the measured data are processed to extract necessary information for computing heating lines for the next iteration. Experiments are performed with a real ship hull plate and the result shows the potential of the proposed procedure for the automation of the line-heating manufacturing process at the shipyard.