Optimisation of vessel trafic using fuzzy linear programming

The optimisation of vessel traffic in narrow channels is concerned with the optimisation of vessel passage times with the regulations in force being complied with. These types of problems are normally solved by classical methods of linear programming. However, the implementation of solutions thus obtained is practically hardly feasible. This is due to difficulties in observing exact times of vessel entries into the fairway, maintaining exactly the expected times of passage along particular fairway sections. Therefore, it becomes necessary to account for inaccurate vessel entry and times of passing particular sections. Consequently, an optimisation problem in this context naturally fits in the format of problems of linear programming with fuzzy coefficients. This approach enables a more flexible formulation of an optimisation problem. From the point of view of the solutions obtained, the interpretation of fuzzy inequalities in the system of constraints is of much importance. The article presents solutions to the vessel traffic optimisation problem with the use of various interpretations of fuzzy inequalities. The calculation results are shown. These refer to vessel traffic in the Szczecin-Swinoujscie fairway. The results have been interpreted and conclusions have been drawn. INTRODUCTION