A Study on Design Support System for Ship Principal Particulars in Consideration of Uncertainty in Product Information

Abstract

Decision of principal particulars is the first stage of ship design. This stage is an important stage where essential information of the ship is decided and the influence on the cost and performance is extremely larger. However, various analyses which contain the error margin are used because detailed information on the ship is not available. Therefore a higher degree of uncertainty is involved in the early design stage. On the other hand, product information is expressed as a fixed value in the present design support system and the systems can not deal with the uncertainties involved in the design information and design process. The purpose of this study is to propose the new design support system considering uncertainties in the product information.The characteristics of the proposed method are following points.1) In order to express product information as unfixed ones, adjustment parameters are used in the new design support system. Fixed product information in a design solution can assume only a single numerical value. On the other hand unfixed product information can be changed to improve the feasibility or optimality because it can assume more than one numerical value. 2) A optimization method named Wildcard GA is newly introduced. In order to express product information as unfixed ones, "^*" (asterisk) is used in the Wildcard GA. "^*" means both "0" and "1". By using this feature, plural design proposal are made from one gene.Some examples using the proposed method are shown in the paper and these are compared with the solution of present technique. As a result, the possibility of the improvement of the design is shown.