Mathematical Model and IDPSO Algorithm Research on Dynamic Fleet Planning

A mathematical model for dynamic fleet planning with multi routes and multi ship, which took the maximum total operation profits as its objective function, was built up according to the characteristics of the shipping company. The model had the following characteristics: Firstly in the model, the long-term fleet planning and short-term scheduling were combined. Secondly, the economic and technology indexes were changed with ship’s age, which fully reflect the dynamic fleet planning. At the same time, because of being at a large scale, discrete, multi-dimensional and multi-stage optimization problem has become very difficult to solve. An improved discrete particle swarm optimal (IDPSO) algorithm was used to solute the model. According to the characteristics of the traditional discrete particle swarm optimization algorithm, some methods including coding strategy, iterative formula, initialization, dimension mutation operator to avoid precocious etc. for discrete particle swarm algorithm, were used to improve the method, which can be more suitable for fleet planning’s mathematical model and to avoid premature phenomenon. Finally, an example was given to show that the improved method was effective.