The Research Of Fast Generation Technology In Ship Structure Based On Pattern Recognition

The preliminary design of the ship structure is a key stage of ship design. This stage alsohas the most huge work load in the whole ship design. How to improve the design efficiency,especially the rapid response capability of the structural design is the key to shorten the entirestage. Although general computer aided design (CAD) software provides parametic designcapability in a certain extent, it is still unable to meet the requirements on the rapid deformationand function-oriented in the design of ship structure. The problem of integrating2-D graphicsand3-D graphics is an important technical difficult in computer aided design now. It is acomplicated and arduous process to obtain design information from2-D graphics and create3-Dmodels quickly and accurately.Based on the above ideas and the ship primary design system NuCAS, recognition andtransformation from2-D graphics and3-D graphics, as well as fast generation of ship structure,is realized by using the method of pattern recognition. Combined with hull molded frame lineand transverse section line of1,000t customs boat, the feasibility of identification is verified.Guiding by the notion of functional models, two basic function are realized, including readingand pattern recognizing of2-D graphics. Reading2-D graphics is a process to read data fromfiles with DXF format to the system and create2-D drawing models. The process of graphicspretreatment include separating and setting the proportion of segment, setting the origin of thescale, deleting annotation and linear regularity by interactive. The value of the2-D graphics datacharacteristics is described by using quantitative techniques. The properties vector of the2-Dgraphics template database. Based on the method of Self-Organizing Map, pattern recognitiontechnical could be uesd to judge the vector. Meanwhile, using top-down hierarchical recognitiontechnology, it could collect design information from2-D graphics through recognition anddetermination of one step or several.The system uses object-oriented programming and database design methodology. Inaccordance with the requirements of software engineering, the program is developed on theVC++2008platform. After the test of the instance,85%of the2-D graphics can be recognize. Itis met basic requirements of ship design. Based on the results of recognition, ship structure couldbe established. Compared with Manual modeling and the modeling accuracy is ensured, timeconsuming in modeling is shorten by a wide margin..This paper made a conclusion of fast generation of ship structure. It also provides severalfurther development ideas about the recognizing process and conversion while the identificationcompleted. The method has a bright future in development and application.