An architectural design of control software for automated container terminals

Automation of handling equipment is a current trend in port container terminal. Because a large number of equipment of different types are involved in the handling operation, the structure of control software is highly complicated. This paper introduces an architectural design of control software and a simulation-based test-bed for testing various control rules of the control software. The suggested control system consists of a ship operation manager (SOM) and system controllers for automated guided vehicles (AGVs) and automated yard cranes (AYCs). A SOM is in charge of dispatching tasks to equipment for preplanned load/unload operations. System controllers assign equipment to the SOM and maintain the information about the location and the status of equipment. To test the control system and the operation methods of the suggested container terminal, an object-oriented simulation system was developed using Java. Using the simulation system, several operation-related issues were tested, including the postponement of dispatching decisions and the sequence rearrangement of AGVs entering transfer areas under quay cranes (QCs).     

Operator-scheduling using a constraint satisfaction technique in port container terminals

In port container terminals, the efficient scheduling of operators of handling equipment such as container cranes, yard cranes, and yard trucks is important. Because of many complicated constraints, finding a feasible solution, as opposed to the optimal solution, within a reasonable amount of computing time can be considered satisfactory from a practical point of view. The major constraints include the following: restrictions on the minimum workforce assignment to each time slot, the maximum total operating time per operator per shift, the minimum and maximum consecutive operating times for an operator, types of equipment that can be assigned to each operator, and the available time slots for each operator or piece of equipment. The operator-scheduling problem is defined as a constraint-satisfaction problem, and its solution is obtained by utilizing a commercial software. An actual problem, collected from a container terminal in Pusan, Korea, is solved through the solution procedure proposed in this study.     

铁路集装箱中心站装卸系统排队模型及分析

针对铁路集装箱中心站装卸系统的设备性能运用闭排队网络模型进行研究。根据铁路集装箱中心站装卸系统的作业特点建立其闭排队网络模型,在该模型中内部集装箱卡车作为顾客在轨道门吊和正面吊两个服务节点以及一个虚设的“运输”服务节点接受服务。由于服务节点的服务时间不能很好地用传统分布表示,导致针对乘积形式排队网络的求解方法并不适用。于是采用近似平均值分析算法求解闭排队网络模型并获得相关的设备性能参数,并分析了装卸系统的设施配置。最终通过与仿真模型所得结果的对比,验证了模型和求解算法的正确性。     

A simulation analysis for a transtainer-based container handling facility

The efficiency of a marine cargo terminal depends primarily upon a smooth and orderly flow of material during the container loading process. It has been observed that the transtainer operation is the bottleneck in the loading process due to the frequent container rehandles and its speed. Past attempts at improving port operations have concentrated on the computerization of the load planning function and the efficient warehouse of the outbound containers. These attempts have, to some extent, been successful but have not been able to significantly eliminate the unproductive movements of the material handling equipment during the load operation.This study proposes a methodology of utilizing a buffer space as a method to increase the utilization of the material handling equipment and reduce the total container loading time. A stimulation model using a graphics simulation system is developed to compare the proposed methodology with the current practice at the Port of Portland.The results from 96 simulation runs show that the use of a buffer space significantly improves the flow of material during the loading operation, resulting in an average of 4% reduction in the total loading time. The methodology proposed in this study can be evaluated and implemented for any transtainer-based container port operation, and is anticipated to make considerable contribution to the plannig of future container port design.     

平行系统方法在自动化集装箱码头中的应用研究

平行系统是一种建立在人工社会和计算实验基础上的科学研究方法,它的特点是既能真实反映现实系统的动态过程,又能实时优化现实系统的控制过程.自动化集装箱码头是一类典型的复杂系统,既存在不计其数的作业方案,同时也有大量的约束条件.如何在最短时间和最低能源消耗的前提下,完成具有间歇和批次特征的集装箱转运任务,是涉及到数学、控制、管理和计算机等多个学科的重大课题.本文采用数据引擎作为人工社会中的基本计算单元,构成一个复杂的平行系统,用于自动化集装箱码头信息控制系统的研究.数据引擎作为一种面向图形化元件组态的计算环境,非常适用于复杂系统的建模与计算.在可视化和动态重构技术的支持下,利用380个数据引擎对一个具有8台岸桥、25辆AGV和16台龙门吊组成的港机系统进行了自动化作业过程的计算实验.研究结果表明,数据引擎技术是实现平行系统的有效方法,由多数据引擎组成的计算环境,能够大幅度降低自动化集装箱码头信息控制系统建模的复杂程度,能够将码头系统的管理和控制过程无缝地融合在一起.该平行系统可直接与港机设备对接,建立“人工码头”和“物理码头”之间的平行关系,从而实现对港机设备的最优控制.     

Workload-based yard-planning system in container terminals

Traditionally, the yard-planning problem has been considered to be the assignment of yard spaces to arriving vessels in practices of container terminals. This study proposes an integrated decision-making framework for the yard-planning that simultaneously considers various resources such as storage space, yard cranes, and traffic area in container terminals for planning. The decision-making framework in this study is based on a mathematical model, which supports intelligent yard-planning activities considering work-loads on various related resources. Further, it is shown that the decision-making framework for the yard-planning can be extended to that for simultaneous decisions on yard plans and handling capacity of yard cranes per block. A heuristic algorithm is also proposed in order to reduce the computational time for planning. Numerical experiments are conducted to validate the models and algorithms proposed in this study.     

Quay crane and yard truck dual-cycle scheduling with mixed storage strategy

In order to enhance the efficiency of port operations, the scheduling problem of the quay cranes and yard trucks is crucial. Conventional port operation mode lacks optimization research on efficiency of port handling operation, yard truck scheduling, and container storage location. To make quay crane operations and horizontal transportation more efficient, this study uses a dual-cycle strategy to focus on a quay crane and yard truck scheduling problem in conjunction with a mixed storage strategy. A dispatching plan for yard trucks is considered, as well as the storage location of inbound containers. Based on the above factors, a mixed-integer programming model is formulated to minimize vessels’ berth time for completing all tasks. The proposed model is solved using a particle swarm optimization-based algorithm. Validation of the proposed model and algorithm is conducted through numerical experiments. Additionally, some managerial implications which may be potentially useful for port operators are obtained.     

Evaluation of the floaterm concept at marine container terminals via simulation

International seaborne trade rose significantly during the past decades. This created the need to increase capacity of existing marine container terminals to meet the growing demand. The major objective of this paper is to evaluate the floaterm concept using simulation modeling and determine if it can improve terminal productivity. The main difference between floaterm and conventional marine container terminals is that, in the former case, transshipment containers are handled by off-shore quay cranes and stored on container barges. Two terminal configurations performance is compared (vessel handling times and equipment utilization) under normal and disruptive conditions. Computational experiments confirm preliminary expectations that the floaterm concept can enhance efficiency of marine container terminal operations under normal and disruptive conditions.     

Scheduling automated transport vehicles for material distribution systems

The rise of advanced manufacturing technology has led to enhanced, efficient material handling equipment in manufacturing and container terminal environments. In order to exploit the full potential of advanced material handling equipment in real-world industrial environments, novel scheduling approaches capable of ensuring integrated operations for multiple automated transport vehicles need to be developed. This research develops a methodology for scheduling automated transport vehicles to ensure the smooth flow of materials in production and container terminal environments. The procedure consists of a mixed-integer programming model and two meta-heuristic-based algorithms that are proposed to achieve quality schedules within a reasonable amount of time. The obtained results show a significant reduction in the earliness or lateness of material delivery tasks and an improvement in operational performance, demonstrating that the proposed approaches are capable of ensuring smooth material distribution by scheduling automated transport vehicles in an integrated manner.     

A quay crane dynamic scheduling problem by hybrid evolutionary algorithm for berth allocation planning

A considerable growth in worldwide container transportation needs essential optimization of terminal operations. An operation schedule for berth and quay cranes can significantly affect turnaround time of ships, which is an important objective of all schedules in a port. This paper addresses the problem of determining the berthing position and time of each ship as well as the number of quay cranes assigned to each ship. The objective of the problem is to minimize the sum of the handling time, waiting time and the delay time for every ship. We introduce a formulation for the simultaneous berth and quay crane scheduling problem. Next, we combine genetic algorithm with heuristic to find an approximate solution for the problem. Computational experiments show that the proposed approaches are applicable to solve this difficult but essential terminal operation problem.     

Choice of loading clusters in container terminals

The storage allocation in the export yard of a container terminal determines the efficiency of container loading. Even if the yard manager has optimised the allocation of export containers to avoid rehandling, conflicts among loading quay cranes can still occur. Thus, all the possible handlings during loading must be considered when organising the yard space. In previous studies, the yard storage allocation has been assessed based on the subblock, which consists of several adjacent bays. However, to minimise all possible handlings in the loading process at the terminal, optimising more flexible storage clusters is also important. Thus, our aim in this research is to model the choice of loading clusters and derive a more flexible allocation strategy for organising the space in the export yard. A bi-objective model is built, which considers both the transportation distance and handling balance between blocks. A model aimed at minimising all possible handlings in the export yard for the loading process is also developed, and several of the insights derived can inform yard management in real-life operations. It is proven that the handling requirements have a significant effect on the choice of loading clusters, and yard managers should consider the various features of liner and loading processes when organising their storage space.     

不确定环境下码头堆场设备集成调度优化

集装箱码头堆场设备调度优化中,对确定条件下的内集卡和场桥的联合调度研究较多,且没有考虑外集卡的随机到达情况。考虑内集卡和场桥作业过程中的不确定性因素,包括：内集卡行驶速度,场桥行走速度和作业时间,并考虑外集卡随机到达堆场对于内集卡调度作业的影响,构建了不确定因素条件下的堆场设备集成调度优化模型,其优化目标是在考虑外集卡随机到达的情况下,最优化堆场设备的作业时间。设计了求解模型的粒子群算法,并比较了一般确定性模型和考虑不确定因素优化模型的结果。算例结果表明,所建立的模型和算法能有效真实地反映不确定因素对集装箱码头堆场设备作业的影响。     

Dynamic rolling strategy for multi-vessel quay crane scheduling

This paper focuses on the container loading and unloading problem with dynamic ship arrival times. Using a determined berth plan, in combination with the reality of a container terminal production scheduling environment, this paper proposes a scheduling method for quay cranes that can be used for multiple vessels in a container terminal, based on a dynamic rolling-horizon strategy. The goal of this method is to minimize the operation time of all ships at port and obtain operation equilibrium of quay cranes by establishing a mathematical model and using a genetic algorithm to solve the model. Numerical simulations are applied to calculate the optimal loading and unloading order and the completion time of container tasks on a ship. By comparing this result with the traditional method of quay crane loading and unloading, the paper verifies that the quay crane scheduling method for multiple vessels based on a dynamic rolling-horizon strategy can provide a positive contribution to improve the efficiency of container terminal quay crane loading and unloading and reduce resource wastage.     

铁路集装箱中心站装卸设备优化调度研究

为了提高铁路集装箱中心站的作业效率,研究了带有干涉约束的轨道式门式起重机（轨道吊）调度问题,为其建立了混合整数规划模型。分析了轨道吊调度问题的作业特点,提出了一种求解该问题的改进遗传算法。在以最小化最大装卸作业时间和均衡设备负荷为目标的情况下,设计了合理的交叉算子和对局部最优个体操作的变异算子。使用随机算例对算法进行测试,结果表明：该算法能在极短的时间内找到此类调度问题的最优或近似最优解。     

A heuristic for the quay crane scheduling problem based on contiguous bay crane operations

Quay cranes (QC) are key resources at container terminals, and the efficiency of QC operations is vital for terminal productivity. The Quay Crane Scheduling Problem (QCSP) is to schedule the work activities for a set of cranes assigned to a single berthed vessel with the objective of minimizing the completion time of all container handling tasks. The problem is complicated by special characteristics of QC operations. Considering QC moving time and interference constraints, the concept of contiguous bay operations is proposed and a heuristic is developed to generate QC schedules with this feature. The heuristic is efficient and effective: it has polynomial computational complexity, and it produces schedules with a completion time objective bounded above by a small increment over the optimal completion time. Importantly, the heuristic guarantees that no quay cranes are idle due to interference. Numerical experiments demonstrate that the optimality gap is small for practical instances.     

基于工业以太网和WinCC的港口移动机械监控系统的实现

本文介绍某港口的大型桥式集装箱起重机的监控系统。上述起重机由GE Fanuc 9030／9070等四种品牌PLC控制，监控系统以工业以太网和WinCC组态软件为基础，实现了对该港口大型移动机械设备的实时数据采集和状态监控。     

集装箱码头装卸作业的调度控制模型及算法设计

对集装箱码头上装卸作业的调度控制直接影响码头的整体运营效率．本文研究了集装箱码头装卸作业的调度控制问题,提出了一个基于柔性化flow shop的集成化控制模型．该问题具有非线性规划(NP：non- polynomial)难度,因此本文开发设计了两类基于优先级规则的启发式调度算法．利用该模型来对码头中多种装卸设备进行总体调度可以提高设备之间的协调性,提高码头效率,降低成本．实验研究证明算法能有效地解决该问题．     

The optimum route problem by genetic algorithm for loading/unloading of yard crane

In recent years, the scale of container transportation and the size of vessels are becoming larger and larger; development of automatic container cranes becomes a necessity. As a key function of automatic control of unmanned cranes, the optimum route can minimize the cycle time by calculating the most efficient combination of horizontal and vertical motions of container loading/unloading. In this study, we have comprehensively studied various issues in the route planning in different fields. Later, the mathematical model based on the problem analysis of loading/unloading process was presented. Particularly, to solve the problem, an optimum route method based on genetic algorithm, which satisfies the criteria such as length, smooth degree and safety distance, was developed. Finally, the computational experiments testified the effectiveness of the algorithm and explored a new way to increase the efficiency of container loading/unloading process.     

基于滚动窗策略的港口海铁联运集装箱转运优化

为了解决港口海铁联运转运集装箱作业规模过大的问题,采用滚动窗策略方法研究港口船舶与列车之间转运进口集装箱作业问题,在每个窗口内建立以列车在港停留时间和集装箱在堆场的堆存时间总时间最小为目标的整数规划模型,设计双层遗传算法进行求解。在此基础上,分别讨论了以固定任务数量和固定时间长度为滚动窗口的情况,对比发现以固定时间长度为窗口的滚动窗策略更适用,并将其与已有的调度策略研究成果作比较分析。最后,设置实验比较双层遗传算法和单层遗传算法,并对设备的工作能力进行灵敏度分析。结果表明,滚动调度策略可以灵活解决大规模集装箱转运问题,双层遗传算法的解优于单层遗传算法的解,增加装卸线数和轨道起重机工作能力可以提高集装箱转运效率。     

大型门座起重机振动模态测试技术探讨

门座起重机作为港口重要的起重运输设备,由于其在潮湿、腐蚀性较大的环境中频繁工作,负荷变化大,且服役时间较长,使得金属结构的振动问题日益突出,非常有必要对金属结构进行振动模态测试分析。本文基于加速度传感脉冲击振测试技术,对某港口MQ1030门座起重机转台平面进行振动测试,并对测试信号进行互功率谱处理,得出转台平面振动模态参数,为该起重机金属结构动态安全评估提供了参考依据。