Strategies to improve the isochrone algorithm for ship voyage optimisation
Yuhan Chen, Wuliu Tian, Wengang Mao
Abstract
An optimisation algorithm is an essential part of voyage planning systems to achieve autonomous and intelligent operations.Various algorithms have been proposed for voyage planning to minimise fuel consumption and increase punctuality.Among them, the isochrone method has been recognised for its robustness and efficiency in voyage optimizations.This paper improves it to overcome its incompetence in multi-objective optimisation and reliable route convergence towards the destination.Five improved methods are proposed and compared, to investigate the most effective enhancing strategy to achieve robustness and practicality in real-time application.By changing search space after the middle stage of the voyage, and formulating an augmented cost function to refine search criteria according to different optimisation objectives, one improved isochrone method (named Isochrone-A*) shows more competitive capability, with potential in real-time implementations.The effectiveness and efficiency of these five improved strategies are compared using four ocean-crossing voyages collected by a chemical tanker.