A non-contact measurement method of ship block using image-based 3D reconstruction technology

Abstract

Nowadays, the traditional measurement methods applied in ship sections/blocks are heavily relied on years of experiences and could hardly meet the shipbuilding requirements due to their complicated and time-consuming processes. Furthermore, along with the development of photogrammetry, the image-based three-dimensional (3D) reconstruction technology has emerged and become flourishing. In this paper, we propose a novel measurement method based on image-based 3D reconstruction technology to measure the construction deformation of ship blocks with high accuracy in a simple way. The scheme only needs photos to rebuild the 3D model of ship block. It includes the camera calibration, the image preprocessing, the feature points matching followed by the steps of dense point cloud generation, meshes partition and 3D reconstruction with texture mapping. In the step of feature points matching, the scale-invariant feature transform (SIFT) algorithm is used and optimized with the addition of the global vector to reduce the mismatch and enhance the reconstruction accuracy. The shipyard experiments with shooting photos of arbitrary steel parts proved that the proposed image-based 3D reconstruction technology is able to be applied to measure the ship blocks with satisfied accuracy and less time in shipbuilding industry or other industries with large-scale one-of-a-kind product as well.