Optimization Model And Algorithm Of Feeder Line Containership Scheduling Based On Variable Speed

Shipping companies continue to seek economies of scale and the continuous development of shipbuilding technology,leading to the large-scale development of container ships.At the same time,large-scale container shipping also contributed to the continuous development of the port,there is an growing number of port handling equipment in port,which matches the large container ships.But the large container ships have high requirements on the ports.Only some of the larger deep-water ports are on their lists.However,more and more customers need"door-to-door" transportation services,which leads to the contradiction between this two aspects.So,a hub-and-spoke shipping network emerges.The hub-and-spoke shipping network refers to that large container ships are used for trunk transportation,giving full play to the economies of scale and the small container ships are used for transport between hub ports and smaller feeder ports.The emergence of the hub-and-spoke shipping network has prompted an increasing number of scholars to paying attention to the branch network optimization problem serving the trunk network.In this paper,by analyzing the status quo of the research on dispatching of regional container ships,we found that although many experts and scholars pay attention to the optimization of shipping grids,they mostly optimize the trunk network by referring the vehicle routing optimization problem,and there are relatively few scholars studying the branch network optimization.The fuel consumption of ships determined by the speed of ships is one of the main components of the operating costs of ships.Some researches have shown that the cost of fuel consumed by during sailing exceeds half of the total operating costs of ships when the fuel price is high.However,most of the current research neglects the influence of speed on operating cost while investigating the problem of dispatching of container ships.Based on the theory of ship speed,this paper designs an algorithm to optimize the speed of branch line ship based on economic speed.On the basis of the above research,knowing loading and unloading capacity of each feeder port,considering the time constraints when the container is delivered to the hub port and the time-window constraints that need to be met when allocating the container to the feeder port,aiming at lowest operating cost of the task,a nonlinear hybrid integer programming model with variable speed was developed.Firstly,this paper used the AMPL integrated development environment to solve the developed model and verify the valid of the model.And then,in order to solve the problem of large-scale branch line ship,this paper has designed a genetic algorithm,at the same time,in order to further improve the accuracy of the solution,this paper also designed a multi-agent evolutionary algorithm which introduces competition operator and self-learning operator to solve the problem.