The Research Of Ship Navigation Performance Design Method Based On Expert System And Database

Ship navigation performance includes stability, speedability, manoeuverability, seakeeping performance and so on. Good navigation performance guarantees that ship can sail and work savely in the course of nature under all conditions.Navigation performance plays an important part in the strategic decision during the prophase of ship design,it also have far-reaching and overall influence on the quality of ship.But, an excellent ship navigation performance design demands to be considered the above monomial navigation performance.It is a difficulty now.Ship navigation performance design is a complicated course which not only depend on experiential formula and theoretical computation,but also rely on some means such as ship model test and ship test,it refers to the using of many knowledge.The development of ship CAD has provided powerful design means for every stage of ship design up to the present.However,presently ship CAD only give priority to aided drawing and structural properties analysis according to algorithm,and it cann't satisfy the demands of ship navigation performance design.Only combining together artificial intelligence and CAD technique, introducing the ideas of knowledge expression and knowledge processing in artificial intelligence,and simplifing the complicated problems can resolve the difficulty.In the paper,expert system(ES) technology in artificial intelligence and database(DB) technology are introduced,and then a system prototype for ship navigation performance evaluation and optimization based on ES/DB is constructed. This system relates to mountains of theoretical knowledge and technology connotation,so it's impossible to reach every aspect in the process of the system research.In the article,the applications of ES/DB technology in ship design and ship navigation performance design are summarized firstly.Next,the character of the knowledge in ship navigation performance design is analysed, the knowledge expression method and saving way in expert system and database are discussed too.Then, based on the exploring of the reasoning mechanism of expert system and database knowledge, the integrated method of expert system and database knowledgeis studied.In addition, Combining the characteristic of ship navigation performance optimization ,a frame of ship navigation performance evaluation and optimization system based on ES/DB is put forward,the function structure and system process of which is also introduced.Finally,using Visual C++ 6.0 and Microsoft Access 2000, a system for ship navigation performance design based on ES/DB is designed,which has friendly interface. Make use of that system navigation performance evaluation and optimizing calculation are carried out for an example of a ship. The operation method of that software is introduced during the course of computing. In the meantime, the advantages of that software are analyzed, and the problems need to be improved are brought forward.The research methods and technologies used in the paper introduce artificial intelligence into the field of ship navigation performance design.They play a guided part in the field, and have important significance in economizing the cost of ship design,shortening ship design cycle,and improving the quality of ship design.