선박 곡부재 계측 포인트에 대한 곡면 모델링 방법

Abstract

Forward and afterward parts of ship and offshore structures are composed of curved plates with a thick thickness. It takes mush time to process the curved plate. If the fabricated curved plate has some dimensional errors, the additional cost is incurred in the assembling process. So, it is important to assess accurate dimensions for fabrication. Recently, photometric systems and 3D laser scanners have been used for this purpose. The dimensional assessment for fabrication is evaluated by comparing the surface created from the measurement points with the design surface. A B-spline surface interpolation is generally used to create the measurement surface, but there may be errors depending on the number and position of measurement points. In this study, we propose a method to improve the generation of the measurement surface. The mesh refinement method is used to obtain an accurate curved surface using a small number of measurement points. A Hermite curve interpolation is applied to reduce the error of the final generated surface. For accurate interpolation, the exact tangential direction is calculated at the vertex of an element, and errors are evaluated for various calculation methods.