# 실시간 적응 A* 알고리즘과 기하학 프로그래밍을 이용한 선박 최적항로의 2단계 생성기법 연구

• Park, Jinmo (Department of Naval Architecture and Ocean Engineering, Research Institute of Marine Systems Engineering, Seoul National University) ;
• Kim, Nakwan (Department of Naval Architecture and Ocean Engineering, Research Institute of Marine Systems Engineering, Seoul National University)
• 박진모 (서울대학교 조선해양공학과, 해양시스템공학연구소) ;
• 김낙완 (서울대학교 조선해양공학과, 해양시스템공학연구소)
• Accepted : 2015.06.22
• Published : 2015.06.30

#### Abstract

This paper proposes a new approach for solving the weather routing problem by dividing it into two phases with the goal of fuel saving. The problem is to decide two optimal variables: the heading angle and speed of the ship under several constraints. In the first phase, the optimal route is obtained using the Real-Time Adaptive A* algorithm with a fixed ship speed. In other words, only the heading angle is decided. The second phase is the speed scheduling phase. In this phase, the original problem, which is a nonlinear optimization problem, is converted into a geometric programming problem. By solving this geometric programming problem, which is a convex optimization problem, we can obtain an optimal speed scheduling solution very efficiently. A simple case of numerical simulation is conducted in order to validate the proposed method, and the results show that the proposed method can save fuel compared to a constant engine output voyage and constant speed voyage.

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