A localization algorithm for improving fabrication of curved hull plates in shipbuilding

Abstract

In this paper, a localization method is proposed for improving the curved plate fabrication process. In the curved plate forming, checking the similarity of a manufactured plate to a CAD model is a critical step, which can be done by aligning the manufactured plate to the CAD model. Although there exist several localization methods, they may not be suitable for the curved plate forming since they do not consider production efficiency (the shortest cutting length for trimming margin) for the subsequent assembly process. Therefore, in this work, a constraint for minimizing the cutting length is introduced in the localization scheme and an algorithm is proposed to handle the problem. A manufactured plate is measured and a constraint is imposed on the reference points of a CAD model and the measured points to limit the direction of the movement of the measured points in the solution process. Through this algorithm, the CAD model and the measured points are aligned such that the shortest cutting length is obtained. After the alignment, the cutting lines are computed for marking on the manufactured plate. Various curved plates taken from the real ship manufacturing process are used to demonstrate the performance of the proposed algorithm.