| The ship's General arrangement design plays an important role in the course of whole shipping design. Drawing the general arrangement graphs is a complex and meticulous task. At present, most designers have used directly computer aided drawing software, such as AutoCAD, to draw the graph. Although the computer aided drawing tools break the designers away from drawing broads, the design efficiency is still not high. Especially one place of the graph is modified, while other related places are also necessary to be modified. The reason is that only geometry information of the graph is used to draw in this way. In fact, there is much other parameter information with engineering meanings in the graph, such as relations of geometry topology and constraints of dimension. Hence adding the function of parameterization design under the foundation of computer aided drawing software can enhance drawing efficiency and quality.The parameterization design is one of the development directions of CAD presently. It can't only provide the function of interactive drawing, but also can implement automatization of drawing. Therefore, the method can lighten working intension for designer, quicken design speed and decrease the amount of information to store. In this paper, the relevant theories about the parameterization design are introduced briefly and the similarities and differences of several parameterization design methods and their application scopes are compared. Then we analyze the constraints of dimension in the general arrangement graph and set up related data structure. Through merging the dimension parameters into the data structure, the solutions to the constraints are solved using geometry organon.Intelligent CAD is another developing direction of CAD. The development status and several methods of intelligent CAD are introduced in the paper. According to the characteristics of design, the feasibility to found expert system oriented the design of general arrangement for passenger shipping is discussed in the paper.Considering the properties of multiple objects and uncertainty in ship's general arrangement design, a fuzzy optimize design method of multiple objects is used to set up the mathematics model of space arrangement of passenger shipping. And in order to optimize space arrangement, a subjection function for the set of fuzzy objects and the set offuzzy judgements is constructed and the optimal point is also formed adopting the maximal and minimal method.Based on the researches as above, a parameterization design and drawing system for the general arrangement graph of passenger shipping is designed, which is developed on the platform of AutoCAD using VC++6.0 and ObjectARX 2000 as development tools. The system is made of four function modules: the module of initializating drawing environment ,the module of graph library for the general arrangement graph, the module of parameterization design for local cabin and the help module of specification about passenger shipping. The main functions of the module for initializing drawing environment are to set up the scale.linetype.breadth and frame of drawings according to the characteristics of the general arrangement drawing to passenger shippings.The main functions of the second module is to establish and extend graph library, retrieve from graph library and output graph blocks. Using the parameterization design method to design interactively and modify automatically graphs of the local cabin are the tasks of the third module. In the help module, the drawing specifications of passenger shipping are integrated, such as equipments of anchor and moor, arrangement of cab, cabin and baggage, measures to come through and ration of passengers, etc.There are some advantages in the proposed system, such as friend interface, operation easily, drawing conveniently and modification automatically. Therefore, it is very suitable for the drawing and modification of the general arrangement for middle or small passenger shipping. |
PDF Full Text Request