集卡预约模式下集装箱码头可变闸口协同调度优化

针对集卡预约模式下集装箱码头传统闸口存在的作业量不均衡、集卡过闸效率不高和集港高峰时段闸口拥堵等问题,引入不同预约时段间服务类型可切换的可变闸口,研究集卡预约模式下可变闸口协同调度问题。基于集卡平均排队时长最小和闸口各通道总作业时间最小的优化原则,在闸口日服务容量满足集卡日抵港量的条件下,建立闸口调度模型。运用逐点固定流体近似算法估计闸口 M/E k(4)/C/∞集卡排队模型获取不同预约时段各通道平均队长后,设计基于2-opt和随机变异规则的混合模拟退火算法求解闸口调度方案。所构造的测试算例验证模型和算法的有效性。计算结果表明:嵌入可变闸口调度模块的集卡预约系统能降低不同时段间集卡平均排队时长曲线的波动幅度;减小高峰时段集卡等候排队过闸的空耗时间;降低闸口日均服务时长和作业成本;协同优化集卡预约机制下闸口各通道资源配置。

Optimization of Variable Coordinated Gate Scheduling in Container Terminals with Truck Appointment System

The variable gates whose service types are switchable in different reservation periods is devised to deal with the problems encountered when operating with the truck appointment system, such as unbalanced gate workload, gate assignment inconvenience for container trucks, and congestion at gates during peak hours. The gate dispatching model is established with the objective of minimizing both the average queuing time and the total operating time of gate channels under the condition that the daily service capacity of the gate meets the daily arrival volume of trucks. The average length of each queue of trucks in different reservation periods is found in a queuing model under the fluid flow based pointwise stationary approximation. A hybrid simulated annealing algorithm based on 2-opt and random mutation rules is designed to produce the gate dispatching scheme. An illustration example shows the improvements achieved by integrating variable gate dispatching module into the appointment system. The test example verifies the effectiveness of the model and algorithm. The results show that the appointment system embedded with variable gate dispatching module can reduce the fluctuation amplitude of the average queuing time curve of the truck at different time intervals, reduce the empty time of the waiting queue at peak hours, reduce the daily average service time and operation cost of the gate, and coordinate and optimize resource allocation of channels of the gate under the truck reservation mechanism.