Abstract:

By analyzing the nonlinear influence of ship speed on fleet planning decision,the mathematical functions are deduced to describe the relationships between the ship speed and three parameters,namely,the round voyage time,the voyage cost,and the ship allocation. On the basis of these functions,a mixed integer nonlinear model for fleet planning is established. Then,according to the characteristics of the nonlinear model,a hybrid particle swarm optimization algorithm is designed by combining the feasibility rule-based update strategy with the local search technique of simulated annealing. Finally,the nonlinear model is compared with the linear one by performing simulations for a shipping enterprise. The results show that the nonlinear model can simultaneously solve the problems of fleet investment,ship allocation and ship speed,and that the corresponding optimal solution accords well with the practical application.

Key words: fleet planning, ship speed, nonlinear model, hybrid particle swarm optimization algorithm