Berthing plan of bulk cargo terminal considering phased and balanced utilization of loading and unloading equipment
Unbalanced use of mechanical equipment such as ship unloaders and belt conveyors in bulk cargo terminals brings about high energy consumption and labor costs. Considering the influence of ship unloaders and belt conveyors operation on ship berthing plan, based on the research on the periodic equilibrium mechanism and modeling of the unloading equipment of the bulk cargo terminal, mixed integer programming models were established to minimize the total service cost and service time of ships in the planning period. Models were solved by CPLEX. The example results show the berthing position, berthing time, operation duration and other conditions of each ship. Under the goal of minimizing the total cost, the relevant indicators of the total service cost of the ship in the planning period are optimized. When the total idle time of ship unloaders of all ships in the planning period is the same, the total service cost is reduced by 9.375% by minimizing the total service cost in the example. Compared with 4 hours per unit time, the comprehensive resource utilization rate of ship unloaders with a unit time of 8 hours decreased by 1.67%, which shows that the change of unit period length can cause the change of comprehensive resource utilization rate of loading and unloading equipment.