Research On Design Method Of Optimal Transoceanic Ship Weather Route Under Complicated Sea Conditions

Economic globalization has made trade between countries in the world increasingly frequent,and the foreign trade of various countries has continued to increase their dependence on the shipping market.Most of the global commodity trade is realized through maritime transportation.With the development of economy and the growth of shipping volume,the greenhouse gas emissions produced by maritime transportation industry are constantly increasing.In addition,the safety and economy of maritime transportation are deeply affected by the complex and changeable marine meteorological conditions.Therefore,it is of great practical significance to ensure the safety and economy of marine transportation under complex sea conditions and reduce the greenhouse gas emissions caused by the shipping industry.One of the important factors to be considered is the ship route when sailing across the ocean.In this paper,the safety,voyage time and fuel consumption of ship are used as indicators to optimize the ship route,and an optimal weather route design method based on genetic algorithm and simulated annealing algorithm is proposed.The main research contents are as follows:Firstly,the mathematical model in the weather route design problem is established.In this paper,a grid system is used to model the navigation environment of ship,which makes it more efficient to process the dynamic weather forecast data.On this basis,the great circle route is taken as the base route,and the search subspace of the optimal route solution is constructed according to the base route.The state of motion of the ship while sailing at sea is analyzed,the 6DOF motions of the ship is simplified,and the description of the ship’s plane motion variables is given.The factors affecting the risk value of the ship route are analyzed,and an effective and reasonable calculation method of navigation risk is proposed.Furthermore,according to actual sailing requirements,different objective functions are established for ship routes,and penalty functions considering navigation risk are introduced into the objective functions.Next,the phenomenon of ship speed loss is studied and the calculation methods of the ship’s fuel consumption are proposed.The characteristic of ship speed loss during navigation is analyzed,and the calculation formula of ship speed used in the design of weather route is given.At the same time,the problem of ship fuel consumption is studied,and two methods for calculating ship fuel consumption are given.One is based on the speed and fuel consumption table,and Lagrange interpolation method is introduced to calculate the fuel consumption of the ship at different speeds.The other is to use artificial neural network to predict ship fuel consumption under different sea conditions.Then,a new optimal weather route design method based on hybrid genetic algorithm is proposed.Based on the genetic algorithm,the simulated annealing mechanism is introduced,and a hybrid genetic algorithm is designed to solve the problem of ship route design.A set of independently adjustable route control variables is established to determine the ship route,and the ship route is coded as a chromosome in the hybrid genetic algorithm.At the same time,the proposed algorithm is improved,fitness calibration measures,niche technology,and multi-population technique are introduced to improve the performance of the algorithm.In addition,the crossover operator is improved,and a hybrid crossover operator is designed.It is composed of Laplace crossover operator and discrete directed crossover operator,which is combined with Gaussian mutation to jointly complete the search of the route solution space.Finally,a simulation platform for ship route optimization is built based on MATLAB,and the optimization algorithm is simulated and analyzed.The algorithm proposed in this paper is coded in MATLAB language,and at the same time,a GUI is designed for the algorithm program,and a simulation platform for the simulation experiment of route optimization is established.Based on the simulation platform,a series of targeted simulation experiments are designed in this paper,and the simulation results are analyzed and demonstrated.The experimental results verify the effectiveness of the algorithm in solving the weather routing problem.