| With the continuous development of international trade,tramp ship transportation,as the main mode of international cargo transportation,has also rapidly developed.The main mode of transportation of bulk dry bulk cargo such as coal,iron ore and grain in international trade during tramp ship transportation.At the same time,tramp ship transportation has the characteristics of unstable cargo source and cargo flow,and irregular ship schedules,routes and ports of call.Therefore,the scheduling of ships is particularly complicated.The flow and direction of cargo carried by tramp ships are different,indicating that the demand for this type of cargo is regional,When the shipping company conducts ship scheduling for the contracted cargo transportation,due to the idle tramp ships in the area,they cannot arrive at the port of shipment within the specified loading period to transport the cargo.In the period of fierce competition in the shipping market,reducing the cost of fuel consumption during transportation and improving the service quality of tramp ship transportation.Scientifically dispatching ships will help reduce ship transportation costs and increase shipping companies’ operating profits.Upon analyzing the current research status of tramp ship dispatching,it is found that the current research does not address the ship dispatching problem under the conditions of the supply and cargo demand of the shipping company’s own ships.It is also necessary to consider the fuel price of each fuel port to choose a fuel port.Under the condition of not delaying the deadline of the contract cargo transportation loading period,choose the best fueling port after weighing the fuel price and transportation cost of each fueling port.However,in actual circumstances,when a shipping company’s ships transport contracted goods in this area,it may happen that its own ships cannot meet the requirements for the transportation of contracted goods during the loading period,Shipping companies will also consider chartering ships of other shipping companies in the market for dispatch.Establish a non-linear programming model with the loading period constraint with the goal of maximizing the total profit of the fleet to complete the contract cargo transportation task during the study period,Solve the problem of tramp ship scheduling with multiple ports,multiple cargoes,multiple ships,and multiple routes.Then,according to the transportation characteristics of tramp ships,the corresponding intelligent algorithm is designed to solve the model.At the same time,a shipping company transports contracted goods to dispatch tramp ships as an example to verify the reliability of the model and algorithm.Research shows that this article provides a scientific method of dispatching ships and distributing cargo for operators of non-scheduled shipping companies.The ship scheduling model constructed in this thesis not only enables the shipping company to successfully complete the transportation of contracted goods,but also reduces the transportation cost of this ship scheduling in terms of the choice of refueling ports,formulating a reasonable scheduling plan,and providing a solution. |
