Ship part nesting by pattern recognition and group arrangement

The automatic nesting for a computer-aided manufacturing (CAM) system in shipbuilding industry requires more constraints than in other fields such as automobile, clothes and shoes. The nesting software has more influence on the productivity of shipbuilding industry, being equipped with such functions as automated operation, user-friendly interface, generation of stable cutting data and draft, and synchronization with enterprise resource planning (ERP). Many algorithms have been developed to increase the utilization rates of sheet metal plates and decrease scrap ratios. However, the minimization of the computational time and scrap ratio has not been fulfilled yet because of inherent constraints in nesting processes. To increase the efficiency of the part nesting in shipbuilding industry, this study presents pattern recognition and group arrangement method. The form features of ship parts are recognized and classified into pre-defined patterns by using the ray projection method. Then, the parts are grouped based on grouping rules. The proposed method has been validated with actual ship parts. ► A pattern recognition and group arrangement method is proposed for ship part nesting. ► Features of ship parts can be identified by using a ray projection method. ► Ship parts are divided into several groups by their patterns. ► Parts are nested first by group arrangement instead of individual arrangement. ► The proposed method has shown improvements in terms of part utilization ratio and computational time.