Application And Key Technology On Intelligent Virtual Layout Design For Ship Compartments

Ship compartment layout design is a repeated and spiral process. Traditional method is to use the mouse and keyboard interactive in CAD system, which makes the ship compartments layout design process fussy. At president, many researches have been done in terms of improving ship design efficiency. CAD/CAM is instead of time-consuming physical work, and increase the design precision. But the design problem sometimes is revealed in after design process, sometimes is revealed in the building processes, which not only delays ship building cycle, but also makes economic great loss. Contrasted to other ship design aspect, it is little research about ship layout design, especially about 3-D virtual spatial compartment layout research, which restricting the improvement of ship design. So it is an urgent problem to seeking new method of ship compartment layout design to change the traditional design state. This paper applies the research result in layout-problem domain, modern virtual reality design method and artificial intelligence technology. This method breaks the constraint of traditional ship compartment layout design, and establishes some theory and technology basis for new ship compartment layout design method. Main research work is following:Firstly, on the basis of analyzing great literature, combining with modern design methodology, virtual reality technology and artificial intelligence, an effective method of the VR design of ship compartments based on knowledge is put forward.Secondly, the IDEFO method is utilized for analyzing the arrangement design. This simplifies the analysis of the information flow and work flow, and helps extract the knowledge of the machinery arrangement design process. Taking engine room for example, according to the different types of ship compartment objects, the design object are classified into physical objects, spatial objects and design constraint objects. On the basis of analyzing design objects and knowledge structure, the knowledge model of ship compartmentlayout design is largely composed of four parts: A knowledge base, an application program for the ship basic calculation, a case base, and a CAD database. The first contains four kinds of design rules and two methods. A compound knowledge system in intelligent 3D-layout design of ship compartment is set up, by using object-oriented mixed knowledge expression of frames, regulars and methods. The integrated frame structural system of intelligent 3D-layout of ship compartment design and CAD system is established.Thirdly, in virtual layout model of ship compartment, a multi-hierarchical part model is used to represent the part attribute information;the position semantics are adopted to describe the layout relationships between the equipments. In virtual environment, the equipment information is classified into equipment part layer, characteristic layer, geometry layer and display layer. By data mapping and constraint mapping, the information association between equipment is realized. The multi-hierarchical part information model not only satisfies the requirement of VR real-time interaction, but also keeps the integrality of CAD design information, which is helpful to handle the equipment information of different layer level according to different task selection in virtual environment. The layout position semantics establish the relationships between the layout constraints and geometry constraints.Fourthly, it is presented a layout manipulating method for ship compartments virtual design based on analysis of freedom degree. The allowable motion space is obtained through the analysis of freedom degree. Then, the equipment arrangement position solving, motion adjustment are devised to achieve the motion navigation in the virtual arrangement environment. The solving method of constraint equations based on optimization approach can deal with under- and over-constrained problem efficiently.Fifthly, the theories and methods to set up mathematical optimal model of 3D-layout design of ship compartments are researched. Mathematical optimal objective functions are raised by using energy methods dealing with non-equal constraints. The evaluating index of maintenance convenience is introduced by using fuzzy function method. The fuzzy function can express the expert fuzzy knowledge, and has the smoothly continuous surface. A pattern search method isfirstly used in optimal layout design of ship compartments. An optimization algorithm of ship compartments layout design is provided.Finally, pipe routes are expressed as a graph and distance matrix. Distance matrix can not only describe orthogonal pipe routes, but also express the orthogonal distance of pipe graph's nodes. The mathematical optimal model of pipe routes is taken routing length and number of bends as primary optimal goal. An optimization method based on genetic algorithm (GA) for pipe routing is present with Evolver software platform.In a word, on the basis of a great deal of correlation literature, this paper combines AI and VR with ship CAD, explores a new method of intelligent VR 3D layout design of ship compartments improving the quality of ship design.