The Optimization Study Of Irregular Feeder Line Container Ship Scheduling

The development of large-scale ship has promoted the increasingly differentiated functions of hub ports and feeder ports,and gradually formed a trunk-line integrated network structure.In this kind of transportation network,feeder transportation provides cargo supply support for trunk transportation,and small sized feeder ships transport containers from feeder ports to hub ports,and then implement intermational trunk liner shipping by large-scale ships.Compared with the development level of trunk transportation,branch transportation faces many practical problems such as complicated operating environment,scattered supply structure and irregular demand,which leads to the existence of tramp feeder business model.Branch line transportation is an important cargo source support for trunk transportation.This positioning has led to many contradictions in the transportation of feeder lines.In this context,how to scientifically allocate the existing capacity of shipping companies,plan a reasonable navigation route,formulate specific dispatching plans,and reduce the operating costs while taking into account the satisfaction of the trunk-branch customers.Is necessary for shipping companies.After summarizing and analyzing the research results in ship scheduling,ship routing and other related fields,it is found that there are few studies on tramp ship transportation based on the characteristics of the internal feeder transportation market,and the role of branch line transportation is measured from a single standard such as cost,profit and time.Focusing on these problems,this paper expounds the characteristics of internal container transportation and transportation network,and then analyzes the contradiction and cost structure of the branch transportation market.Then taking the tramp ship transportation as the research object,and aiming at balancing the contradictions of branch transportation,the feeder line ship scheduling models are established.In the models,the planning period is divided into several time periods.According to the freight demand of different ports,the ship considers the actual constraints such as the time limit of different hub-port ships and the capacity of the branch vessels,and with the aim of minimizing the operating costs(ship allocation cost,transportation cost,container handling cost,parking cost)and cargo rejection cost,ship routing and scheduling plan is concluded.Then,based on the research results of the harmony search algorithm in other fields,the basic harmony search algorithm is improved and applied to the problem of this paper.Finally,an example is given to analyze company A,which provides regional container transportation(collection and distribution)services for different trunk ships.The results show that the model and algorithm of this paper can well design the ships’routes and scheduling plan under the principle of balancing the branch operating cost and service level of the trunk/branch customer,which provides support for shipping companies to make the overall conductive decision.