Aheuristic Algorithm for Berth Scheduling Problem in Container Ports

In this paper,the berth scheduling problem is transformed into a special two-dimensional packing problem with some constraints.A nonlinear programming model for the problem is established,and a heuristic algorithm is proposed to solve the model.Simulation results show that the algorithm can improve the utilization of berths on discrete berth scheduling in the container port.

Study on Ship Automatic Berthing System with Mooring Lines

This study describes an automatic berthing system with mooring lines. It is designed to be berthed by using mooring device on the upper deck of a ship. It is to berth once maintaining parallel with the quay by controlling both forward and aft breast lines. Berthing method is used through length adjustment of mooring lines connected between ship and quay by controlling the angular velocity and the torque of hydraulic motor in mooring device. The study is conducted under three changing conditions of draft, such as even-keel, rise of the gravity center and trim to stern. Variables affecting berthing stability are determined based on the control performance of each condition. Bond graphs method is used to model the system. Controller is designed as PID control method of reference-model algorithm. The control program is composed of synchronous control system based on the equations derived with the numerical analysis. The tank test is conducted to verify the usefulness of the control program.

Integration of Berth Allocation and Quay Crane Assignment in Tidal Container Ports

Tide is a significant factor which interferes with the berthing and departing operations of vessels in tidal ports. It is a preferable way to incorporate this factor into the simultaneous berth allocation and quay crane( QC) assignment problem( BACAP) in order to facilitate the realistic decision-making process at container terminal. For this purpose,an integrated optimization model is built with tidal time windows as forbidden intervals for berthing or departing. A hind-and-fore adjustment heuristic is proposed and applied under an iterative optimization framework. Numerical experiment shows the satisfying performance of the proposed algorithm.

Real Time Math Simulation of Contact Interaction during Spacecraft Docking and Berthing

Contact reactions of guide surfaces of assembly interfaces lead to the decreasing of theirs lateral and angular misalignments. The focus of this paper is the development of algorithms for computation of guide surfaces contact forces with acceptable engineering accuracy for real time simulation of assembly operations. Therefore, each complex guide surface is described as a set of contacting elements. Each contacting element for one＇s part can be represented by a finite set of geometric primitives which geometry is described by low order algebraic equations. So contact conditions and geometric parameters for all pairs of primitives are determined by analytical expressions. Math models are developed for two classes of contact interaction. The first class includes all cases when each contacting surface has several degrees of freedom of motion. Therefore, contact reactions introduced into differential equations of motion are calculated by using contacting elements penetrations, stiffness and damping parameters. The second class corresponds to all cases when one of contacting surfaces has insignificant inertia and only one degree of freedom of relative displacement counteracted by a spring. Here contact reactions are calculated from spring tension with any practical accuracy. This is very useful in some practical applications. Presented algorithms provide real time simulation together with some approaches for reduction of redundant comnutations.

Modeling and Simulation of Automatic Berthing based on Bow and Stern Thruster Assist for Unmanned Surface Vehicle

In order to solve the technical problems of autonomous berthing of the Unmanned Surface Vehicle(USV),this research has met the requirements of maneuverability berthing under different conditions by effectively using the bow and stern thrusters,which is a technological breakthrough in actual production and life.Based on the MMG model,the maneuverability mathematical model of the USV with bow and stern thruster was established.And the motion simulation of USV maneuvering was carried out through the numerical simulation calculation.Then the berthing plan was designed based on the maneuverability analysis of the USV low-speed motion,and the simulation of automatic berthing for USV was carried out.The research results of this paper can be of certain practical significance for the USV based on the support of the bow and stern thruster in the berthing.At the same time,it also provides a certain theoretical reference for the handling of the USV automatic berthing.

Experimental Study on Allowable Berthing and Mooring Conditions of An Oil Tanker

When an oil tanker under the combined action of wind, waves and tidal current and is berthed or moored to a platform, the impact forces on the fenders and the tensile force in the mooring lines are important factors in the studies of berthing and mooring conditions. Based on the experiment of a berthing and mooring tanker model under the action of wind, wave and tidal current in the same direction, this paper studies the allowable berthing and mooring conditions by considering the tensile forces of mooring lines and impact forces on the fenders, as well as the impact energy on the fenders. And a method has been proposed here for motion amplitude analysis. A successful method to decrease impact forces on the fenders is put forward. Blowing in wind and blowing off wind and different angles between waves and the fenders are considered in the experimental study. In the berthing tests of the tanker model, the impact forces are measured and the impact energy is calculated, then the berthing conditions are determined. In the mooring tests of the tanker model, the mooring line tensile forces and impact forces are measured, and the allowable mooring conditions are given that will be useful to engineering design.

An Improved Genetic Algorithm for Berth Scheduling at Bulk Terminal

Berth and loading and unloading machinery are not only the mainfactors that affecting the terminal operation, but also the main starting point ofenergy saving and emission reduction. In this paper, a genetic Algorithm Framework is designed for the berth allocation with low carbon and high efficiency atbulk terminal. In solving the problem, the scheduler’s experience is transformedinto a regular way to obtain the initial solution. The individual is represented as achromosome, and the sub-chromosomes are encoded as integers, the roulettewheel method is used for selection, the two-point crossing method is used forcross, and the exchange variation method is used for variation in the procedureof designing the Algorithm. Considering the complexity of berth schedulingproblem and the diversity of constraints and boundary conditions, the geneticalgorithm combines with system simulation to get the final scheme of berthallocation. This model and algorithm are verified to be practical by analyzingmultiple sets of examples of shorelines with different lengths. When comparedwith the traditional algorithms in three aspects which includes berth offsetdistance, departure delay cost and energy consumption of portal crane, the resultindicates that the improved algorithm is more effective and feasible. The studywill help to lower energy consumption and resource waste, reduce environmentalpollution, and provide a reference for low-carbon, green and sustainable development of the terminal.

Berth-crane allocation under uncertainty:dynamic modeling and nested Tabu search

The integrated berth-crane allocation problem at container terminals is addressed under the uncertainty of vessel arrival time at operational level. To ensure both robustness and flexibility of the 2-stage decision processes,a dynamic decision framework is proposed based on the dynamic analysis of information and operation at container terminal. A mixed integer programming model is established aiming at minimizing total cost of all vessels,including the cost of fixed to-be-executed decisions in the 1^(st) stage and expected cost of the adjustable stochastic-scenario-based decisions of all scenarios in the 2^(nd) stage. A multi-layer nested Tabu search is proposed for each epoch dynamically. Finally numerical experiments have been conducted to testify the effectiveness and efficiency of the proposed model and algorithm.

Numerical Prediction of Hydrodynamic Forces on A Berthed Ship Induced by A Passing Ship in Different Waterway Geometries

An investigation has been conducted to quantify the effect of waterway geometry on the form and magnitude of forces and moment experienced by a berthed ship due to a passing ship.By using the dynamic mesh technique and solving the unsteady RANS equations in conjunction with a RNG k？ε turbulence model,numerical simulation of the three-dimensional unsteady viscous flow around a passing ship and a berthed ship in different waterway geometries is conducted,and the hydrodynamic forces and moment acting on the berthed ship are calculated.The proposed method is verified by comparing the numerical results with existing empirical curves and a selection of results from model scale experiments.The calculated interaction forces and moment are presented for six different waterway geometries.The magnitude of the peak values and the form of the forces and moment on the berthed ship for different cases are investigated to assess the effect of the waterway geometry.The results of present study can provide certain guidance on safe maneuvering of a ship passing by a berthed ship.

Nesting and Berth Allocation by an Expert System Using Heuristic Search

Nesting is a common problem in industries such as shipbuilding, auto-maker, clothing, shoe-making, and furniture, in which various parts are cut off from a stock or stocks while minimizing the wastes or maximizing the utilization of the stock. Berth allocation at seaside is also considered one form of two dimensional nesting problems, in which a ship is assigned a location for service during a certain time slot. This paper presents an expert system using a heuristic search method for nesting problems. The parts and stocks are represented by pixels with which utility function is used to evaluate current state in search tree. The system is developed in CLIPS, an expert system shell and applied to various example problems with different constraints and to a berth allocation example to illustrate its applicability under different conditions.

Collaborative Optimization of Berth Allocation and Yard Storage in Container Terminals

Considering the interaction between the berth and the yard,this paper studies the collaborative optimization problem of berth allocation and yard storage from the point of the ships over a certain planning period.This collaborative optimization problem is formulated as the integer programming,which aims at minimizing the total truck travel distance.And decision variables are the berthing positions for visiting ships and the storage positions for export containers.Meanwhile,this paper demonstrates the complexity of the problem in theory.And the hybrid tabu genetic algorithm is designed to solve the problem to obtain the optimal berth allocation position and export container storage position.For this algorithm,the rule is applied to generate the initial feasible solutions,and the crossover and mutation operation are simultaneously applied to optimize the initial solutions.Finally,this paper discusses two different scenes:the same berth scene and the same ship scene.The influence of two different scenes on truck travel distance is analyzed by different numerical examples.Numerical examples’results show that the collaborative optimization of berth allocation and yard storage can effectively shorten the truck travel distance and improve the efficiency of terminal operation,which provides the decision support for terminal operators.

An Analysis of Net Berth Productivity in the Handling Operations with Dry Bulk Cargoes in a Seaport

Productivity at the berth is one from the group of port productivity measures which is closely tied to ship turnaround times.Net berth productivity is value of productivity related to the operational time at the berth.Based on the facts identified from available literature about minor share of researches related to the net berth productivity in the handling operations with dry bulk cargoes in a seaport,it was decided to take this port productivity metrics as an object of a research.After a detailed analysis of different categories of the net berth productivity in the handling operations with dry bulks,key groups of influential factors which determine values of the net berth productivity are identified and systematized.Some principal elements related to improving net berth productivity are taken into consideration,too.Concrete results shown in this paper are related to the Dry Bulk Cargo Terminal in the Port of Bar(Montenegro).

NUMERICAL SIMULATION OF TRANSIENT FLOW AROUND A SHIP IN UNSTEADY BERTHING MOTION

Ship berthing is a specific maneuver operation. The flow around a berthing ship and the forces acting on the hull are quite different from those for a ship in normal navigation. By solving the unsteady Reynolds-Averaged Navier-Stokes （RANS） equations, the transient flow field around a ship undergoing unsteady lateral motion is simulated and the varying lateral hydrodynamic force acting on the hull is evaluated in this article. The numerical results obtained with different turbulence models are analyzed and compared with experimental results and other numerical results published in literature, and a turbulence model more suitable for simulation of the viscous flow around a ship undergoing unsteady berthing is determined.

Analysis of Angular Side Berthing Against a Rubber Cone Fender

This paper analyzes fender selection process in berth design and focuses on the case of a rigid berth with rubber cone fenders.Fender types and performance comparison methods are studied along with current numerical models.Berth design methods are analyzed with a focus on berthing energy calculation and fender selection.A new approach to determine the required fender capacity is suggested.A finite elements rubber cone model is tested and used in simulations of angular side berthing.Results show that the energy absorbed by the fender can be much higher than what can be calculated with the current berth design method.A new form for the expression of the energy that must be absorbed by the fender during angular berthing impact is suggested.

考虑氢-电负荷特性的港区能量管理方法

为降低港区碳排放并提高港区运行经济性,文中提出一种考虑港区氢-电负荷特性的协调港区氢-电能源供需不平衡的能量管理方法。在港区交通调度阶段,为得到港区日氢-电负荷曲线,按照港区生产作业流程,先通过基于泊位-岸桥优化调度得到港区电力负荷模型,再以集装箱转运总氢耗最小为目标建立基于堆场优化调度的氢负荷模型。在港区能源调度阶段,建立了考虑港区碳排放成本的港区日运行总成本模型,以得到港区能源的日前调度策略。基于历史数据的仿真结果表明,采用所提方法得到的港区运行总成本比仅采用锂电池场景和仅采用电制氢设备场景的运行总成本均显著降低。同时,碳排放比仅升级固定式物流设备场景和仅升级移动式物流设备场景的碳排放均有显著下降。

Numerical Study on Water Depth Effects on Hydrodynamic Forces Acting on Berthing Ships

Due to the restrictions of ports, maneuverability of berthing ships will be affected significantly by water depth. In the present study, numerical simulation of the berthing maneuver of a ship with prescribed translational motion is performed by solving the Reynolds-averaged Navier-Stokes (RANS) equations based on overset grid, and the effects of the quaywall and freesurface are taken into consideration. To validate the present numerical method, comparison is performed between our results and the other results or measurements. It is found that the agreement is significantly better than that resulting from previous CFD-based approach. Subsequently, the effects of various water depths are investigated to evaluate their influences on hydrodynamic forces. The present results can provide helpful guidance on safe maneuvering for vessels’ berthing and fender system design in quays. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

三峡升船机船厢应对水位波动对接方案优化及应用

针对三峡升船机引航道水位快速波动条件下,船厢对接位置选择不合理影响升船机安全高效运行的问题,本文开展了三峡升船机应对水位波动的船厢对接方案优化,研究提出设置过厢船舶临时靠泊区和船厢对接位置判断方法,实现了船厢与航道快速准确对接。总结三峡升船机船厢对接优化方案,现场验证前后受水位波动影响情况的变化。结果表明:对比原方案,方案优化后能够提升升船机船厢对接位置合理性和准确性,并有效减少航道水位波动对升船机运行的影响,为建设在自然河流上的升船机安全高效运行提供了一种更为行之有效的船厢对接方法。

智能船舶靠泊技术研究热点与趋势

在梳理近年来国内外智能船舶靠泊技术研究现状的基础上,首先从靠泊方式、数学模型和控制算法3个方面分别归纳靠泊技术的研究热点与应用情况,分析智能船舶靠泊技术在自主性、建模精度、路径规划、控制算法、节能效果和系统测试等方面尚待解决的问题。然后,从航海实际需求出发,提出下一步需要突破的有关信息融合、在线建模、智能决策、算法优化、绿色节能和测试技术等方面的核心理论和关键技术问题,努力提升靠泊技术的自主性、鲁棒性、快速性和“韧性”,助力实现安全、绿色、高效的智能航运目标。

考虑占用率的大型停车库泊位动态分配模型

为提高驾驶员泊车效率,本文考虑不同停车库占用率下的停车库运营者及驾驶员泊位分配需求,构建大型停车库泊位分配模型。本文引入停车库占用率将停车库空满等级划分为空闲泊位充裕时段、空闲泊位适中时段、空闲泊位紧缺时段,综合考虑停车库运营者运营管理需求与驾驶员快速寻泊需求,以寻位行驶时间、离开停车库行驶时间为参数构建运营管理时间效用函数,以寻位行驶时间、停车入位耗时、步行时间为参数构建驾驶员泊车耗时效用函数;将运营管理时间效用与驾驶员泊车耗时效用加权统一为总时间效用,以总时间效用最大化为目标,建立兼顾停车库运营者及驾驶员泊位分配需求的泊位分配模型;引入泊位利用率、停车总耗时量化模型性能。以西安市某大型商业停车库为例,选取9:00、11:30、13:00表征空闲泊位充裕、空闲泊位适中、空闲泊位紧缺时段进行泊位分配。不同停车库空满等级下,停车库内空闲泊位的总时间效用与停车总耗时均呈负显著相关,其中,空闲泊位充裕时段,停车库内空闲泊位的总时间效用与停车总耗时的相关性最弱,相关系数为-0.461;空闲泊位紧缺时段,停车库内空闲泊位的总时间效用与泊位利用率呈正显著相关,相关系数为0.710。研究表明本模型可在优选停车总耗时较小泊位的基础上,为停车高峰时段预留利用率较高的泊位,提高空闲泊位紧缺时段的泊车效率及驾驶员的泊车满意度。

集装箱港口多码头泊位联合分配优化研究

多码头泊位联合分配是港口资源整合、提升服务水平的重要手段。针对集装箱港口多码头泊位计划,考虑不同码头泊位条件、岸桥能力等因素,构建多码头泊位-岸桥集成分配数学模型。设计改进灰狼算法(IGWO),利用离散化映射进行编码设计,基于优胜劣汰法实现种群动态进化。设计算例,将IGWO与果蝇算法和粒子群算法进行对比。结果显示:IGWO算法优化结果分别提升16.6%和21.1%;利用IGWO对不同船舶到港密度泊位算例进行求解,其中,多码头泊位分配可有效减少总时间成本及延误船舶数量,节省岸线资源约10%。结果表明:设计的模型及算法可有效解决多码头泊位联合分配问题。