基于多智能体仿真的集装箱港口作业效率研究

集装箱港口生产作业系统是复杂的离散事件系统,数学建模方法难以构建针对整个系统的模型,而基于过程的仿真模型通常缺乏对设备调度的灵活性。为准确描述我国集装箱港口的作业流程,分析内卡配置数量对港口作业效率的影响,提出了基于事件驱动的集装箱港口多智能体(Multi-Agent)仿真模型。仿真结果表明:岸桥平均装卸效率(GCR)随着内卡数量的增加先急剧增加后缓慢增加,船舶平均等待时间(AWT)和平均在泊时间(AST)与岸桥平均装卸效率呈明显负相关关系。     

集卡调度方式对集装箱港区碳排放的影响

集卡已成为集装箱港区内的主要碳排放源,尤其两艘大型集装箱船舶同时作业时,港区内集卡碳排放问题严重。针对该情况下集卡调度模式的特征,基于智能体仿真技术构建集装箱码头生产作业微观仿真模型,定量分析传统先卸后装、双船一装一卸、同贝同步装卸工艺下集卡调度方式与集卡配置数量对船舶在港时间、集卡碳排放量的影响。实例表明,采用同贝同步装卸作业方案可保证装卸效率,并有效减少集卡碳排放,而集卡配置数量只对集卡怠速行驶产生的碳排产生影响。     

场桥防吊拖架系统

场桥在作业过程中把拖车车架吊起的事故时有发生 ,此类事故引起的后果严重。防吊拖架系统在场桥上的应用 ,很好地解决了这一问题。     

A fuzzy AHP decision support system for selecting yard cranes in marine container terminals

One of the most important issues that planners and developers of ports have to address at the planning process of container terminals is how to effectively optimize truck turnaround times. The time that a truck spends at a container terminal for loading and/or unloading of cargo is a real cost scenario which affects not only the smooth operation of ports but also the overall cost of the container trade. The main objective of this article is to provide a decision support tool for selecting the best container yard gantry crane for loading/discharging operation of trucks at the landside of marine container terminals. Achieving this goal, this study aims at introducing and recommending the multiple attribute decision-making and the fuzzy analytical hierarchy process models that have been proven to provide a concrete basis for such a selection decision.     

A study of the changes in performance of quayside container cranes

The learning effect, whereby performance improves with experience, is well documented for manufacturing situations. This article applies these learning concepts to quayside container cranes, in order to determine the relationship between number of containers moved and unloading time. The results show that crane performance has improved with time, and that the learning effect is essentially the same for four ports. Container vessel operators are looking for consistency in port operations. An analysis of variability for one port shows that this consistency is not always achieved and that crane performance does not appear to be related to vessel size.     

Application of El Farol model for managing marine terminal gate congestion

Truck queuing at marine terminal gates has long been recognized as a source of emissions problem due to the large number of trucks idling. For this reason, there is a great deal of interest among the different stakeholders to lessen the severity of the problem. An approach being experimented by some terminals to reduce truck queuing at the terminal is to provide live views of their gates via webcams. An assumption made by the terminals in this method is that truck dispatchers and drivers will make rational decisions regarding their departure times such that there will be less fluctuations in truck arrivals at the terminal based on the live information. However, it is clear that if dispatchers send trucks to the terminal whenever the truck queues are short and not send trucks when the truck queues are long, it could lead to a perpetual whip lash effect. This study explores the predictive strategies that need to be made by the various dispatchers to achieve the desired effects (i.e. steady arrival of trucks and hence less queuing at the seaport terminal gates). This problem is studied with the use of an agent-based simulation model and the solution to the well known El Farol Bar problem. Results demonstrate that truck depots can manage (without any collaboration with one another) to minimize congestion at seaport terminal gates by using the provided real-time gate congestion information and some simple logics for estimating the expected truck wait time.     

Empirical studies on yard operations Part 2: Quantifying unproductive moves undertaken in quay transfer operations

The impact of higher container stacking on yard operations has been treated as one of the major factors influencing the efficiency of terminal operations. For terminal operators who have to increase their storage capacity by way of higher container stacking, the consequences must be carefully measured. This paper examines the unproductive container movements undertaken in one high throughput terminal with high land productivity, and provides an example of how terminal operator handles the yard operations and the possible impact on areas of operation.     

Empirical studies on yard operations Part 2: Quantifying unproductive moves undertaken in quay transfer operations

The impact of higher container stacking on yard operations has been treated as one of the major factors influencing the efficiency of terminal operations. For terminal operators who have to increase their storage capacity by way of higher container stacking, the consequences must be carefully measured. This paper examines the unproductive container movements undertaken in one high throughput terminal with high land productivity, and provides an example of how terminal operator handles the yard operations and the possible impact on areas of operation.     

轨道式龙门起重机旋转集装箱形式的探讨

以选择具有旋转机械功能的铁路堆场轨道吊为出发点,对可以实现集装箱旋转功能的现有几种类型轨道吊的优缺点进行分析,并针对我公司铁路堆场布置及装载货物的实际情况进行探讨,最终选择适合我公司的轨道吊。     

An energy-cost approach for evaluation of operating systems in container terminals

The planning, design and development of a container terminal with optimum size and capacity and with a minimum capital cost is fundamentally dependent upon the loading and discharging operations at the quayside. Achieving this purpose, terminal operators have to choose the best operating system in the container yard. The decision on which equipment is used at container terminals depends on several factors. The purpose of this study is to provide a new decision making tool using the first law of thermodynamics. It considers a port as a control volume of a fluid system and models the port and its traffic on it. The results of this study evaluate container yard operating systems and set up a basis for decision making to select the best alternatives.     

A simulation optimization approach for solving the dual-cycling problem in container terminals

Dual cycling is an operation technique whereby quay cranes perform loading and unloading operations simultaneously in the same ship bay. In this article, a mixed-integer programming model for quay crane dual-cycling scheduling is developed. The model considers the stowage plan of outbound containers and the operation sequence of quay cranes. To solve the model, a heuristic method, called bi-level genetic algorithm, is designed. Meanwhile, a simulation optimization method integrating the intelligent decision mechanism of the optimization algorithm and evaluation function of simulation model is proposed. Numerical experiments indicate that dual cycling can reduce the operation time of quay cranes compared to the method of scheduling loading and unloading separately. Moreover, the model and algorithms developed in this article can tackle quay crane dual-cycling problem efficiently.     

海港集装箱码头新型装卸工艺技术和模式的探讨

通过对国、内外海港集装箱码头新工艺和新技术开发研究情况的介绍,认为采用节能减排技术、新型高效的岸边装卸桥和堆场水平运输机械设备,建设自动化集装箱堆场(ACY)和全自动化的集装箱码头(ACT)已成为今后海港集装箱码头发展的方向.根据新时期我国海港集装箱码头发展的特点,提出集装箱码头和堆场装卸工艺模式创新的设想,并建议创造...     

大型集装箱港口近港集疏运道路服务水平提升

公路集疏运是港口集疏运的主要方式之一。针对大型集装箱港口吞吐量较大造成的近港主要集疏运道路拥堵问题,进行现状情况的分析研究,总结近港道路的交通特征和拥堵原因。在此基础上,采用节流和开源的方法,从降低小时流量和提高通行能力的角度出发,提出设置港外堆场的方式平衡公路流量和引入无人驾驶降低平均车头时距两个方面的措施。并以上海洋山深水港区为例,应用本文提出的改善措施,详述港外中转堆场规模、选址和在无人集卡运输要求下集疏运道路断面调整方案,计算得出"改善后集疏运道路服务水平显著提升"的结果,印证了本文提出措施的可行性,为港口集疏运规划决策提供思路。     

Extended gate operations at the ports of Los Angeles and Long Beach: a preliminary assessment

The paper examines the implementation of extended gate operations at the Los Angeles/Long Beach ports. The programme, known as PierPASS, assesses a Traffic Mitigation Fee (TMF) on eligible containers moved into and out of the ports during peak hours. The fees are intended to defray the costs of extended operations at the ports.

In this paper we focus on the implementation of the programme and its outcomes over a year of operation. We discuss the motivations and actions of key stakeholders and place our examination in the institutional framework of the goods movement supply chain. Our results are based primarily on a series of extended interviews with stakeholders, together with data provided by PierPASS and by three drayage trucker surveys. We find that the PierPASS programme was a response by terminal operators and steamship companies to growing political pressure. Given their market power within the supply chain, they were able to create a programme that protected their interests yet responded to political imperative. The PierPASS programme has been a success: the peak fee has shifted a significant share of cargo to evenings and weekends, as intended. Winners and losers of PierPASS reflect the larger structure of the international supply chain.     

Extended gate operations at the ports of Los Angeles and Long Beach: a preliminary assessment

The paper examines the implementation of extended gate operations at the Los Angeles/Long Beach ports. The programme, known as PierPASS, assesses a Traffic Mitigation Fee (TMF) on eligible containers moved into and out of the ports during peak hours. The fees are intended to defray the costs of extended operations at the ports.

In this paper we focus on the implementation of the programme and its outcomes over a year of operation. We discuss the motivations and actions of key stakeholders and place our examination in the institutional framework of the goods movement supply chain. Our results are based primarily on a series of extended interviews with stakeholders, together with data provided by PierPASS and by three drayage trucker surveys. We find that the PierPASS programme was a response by terminal operators and steamship companies to growing political pressure. Given their market power within the supply chain, they were able to create a programme that protected their interests yet responded to political imperative. The PierPASS programme has been a success: the peak fee has shifted a significant share of cargo to evenings and weekends, as intended. Winners and losers of PierPASS reflect the larger structure of the international supply chain.     

旋转吊控制系统设计及其技术创新

使用正面吊调箱门是目前国内集装箱码头广泛采用的作业模式。它需要拖车来回掉头,存在需要场地比较开阔,油耗大、环境污染等劣势。为提高效率,节能减排,对场桥进行了“油改电”改造。并用旋转功能的旋转吊替代正面吊调箱门。重点阐述其中电气控制系统关键部分的创新设计方案及技术特点。     

Impact of container chassis management practices in the United States on terminal operational efficiency: An operations and mitigation policy analysis

Existing policies designed to mitigate the environmental and social impacts of truck queuing at maritime terminals often focus on congestion problems outside of the terminal gate, targeting a reduction in the waiting and turn time of trucks as the measure of success. This paper evaluates the impact that intra-terminal truck and equipment movements have on the terminal’s overall performance and the implications that these movements have on the effectiveness of current mitigation policies. Through a simulation of terminal processes occurring at Southern California ports it is shown that measures driving reductions in truck turn times impose greater operational loads on terminal equipment, essentially transferring savings in truck turn time rather than eliminating it in terms of the overall system. Consequently, the paper finds that total truck and cargo handling equipment movement and operational time constitutes a more accurate measure of the effectiveness of policies seeking to mitigate the impacts of truck operations at marine terminals.     

船舶液压起重机延迟反馈吊重消摆控制

由于操纵和工作环境的变化，起重机的吊重在工作过程中会产生摆动，这种摆动降低了起重机的工作效率和安全性能。文章以集美大学轮机工程实验中心船舶液压起重机为研究对象，采用机电液仿真建模技术及拉格朗日方程，在MATLAB Simulink仿真软件平台上，建立起重机操作液压系统及吊重摆动模型，采用与试验数据对比的方法对所建立的模型进行验证。设计基于吊重摆动位置延迟反馈的控制器，通过将延迟反馈信号叠加到操作信号上的方法实现吊重的消摆控制。结果表明，在各种操作情况下，延迟反馈控制器均能很好地抑制吊重的摆动。     

单箱轨距起重机自动化码头装卸工艺可行性分析

针对自动化集装箱码头堆场起重机大车作为主要工作机构导致能耗增加、效率降低等问题,研究了一种新型单箱轨距集装箱堆场起重机装卸工艺。基于Witness平台,分别建立了新工艺与经典工艺的集装箱码头仿真模型,通过计算和仿真试验对比分析了设备投资、能耗、年通过能力等技术指标。结果表明新工艺具有设备投资低、能耗低、装卸效率高等优势,对箱区间存在的作业干扰问题提出了相应的建议,为自动化集装箱码头的创新发展提供了新方向。     

An integrated programming model for storage management and vehicle scheduling at container terminals

In this paper, we study the optimization of yard operations, which are critical for the terminal efficiency. A linear mixed integer programming (MIP) model is proposed for scheduling different types of equipment and planning the storage strategy in an integrated way. We also investigate a nonlinear mixed integer programming (NLMIP) model to reduce the number of constraints and the computational time. A set of numerical results are carried out for the comparison between the linear model and the nonlinear model. Finally, we propose a genetic algorithm for the MIP model to illustrate how large scale problems can be solved and to show the effect of different factors on the performances of the optimization model.