Research On Port Tugboat Scheduling Optimization And Simulation

The tugboat operation system is’the first service station’ in the whole port logistics system. Studying how to make feasible scheduling plans for tugboats, is an important topic which can greatly improve the port operation efficiency, reduce the fuel consumption, and improve the port competitiveness. The main work in this dissertation about the above problems is as follows:(1) A2-stage tugboat scheduling model considering multi-anchorage bases was formulated. The hybrid simulated annealing algorithm (HSA) was proposed to solve the problem. Numerical experiments reveal that the HSA resolved results are better than those from the simple SA and existing scheduling rules, which prove the effieciency of the proposed algorithm. By comparisons between the total operation times under different operation modes, the empiristic rules for rational selection on operation modes were concluded.(2) By comparisons between the total operation times and utilization of tugboats on whether tugboats return to the anchorage bases during the planning horizon using the proposed MHSA, decision support can be made on whether tugboats should return to the anchorage bases after finishing each operation, thus the fuel consumption can be reduced and the utilization of tugboats can be improved.(3) After testifying the efficiency of the formulated3-stage model considering the shifting-berth operation and the proposed MHSA2algorithm, the dissertation pointed out by the sensitivity analysis on different parameters, that the total operation time of tugboats is most sensitive to the proportion of the shifting-berth operation and ship style, and influenced slightly by the tugboat deployment scheme, and not sensitive to the handling times.(4) The simulation of the tugboat operation system was realized with the Arena software based on the designed simulation procedure. Results of the simulation run can be concuded as follows:the turnaround and waiting times of ships with more quantities, larger scales are obviously larger than those of normal ships. Besides, comparisons between the tugboat utilization from the simulation system and proposed algorithm point out:by using the proposed algorithm to make the scheduling plans for tugboats, more ships can be served under the same tugboat resources compared with the existing operation system.