Cooperative Multi-Agent Control for Autonomous Ship Towing Under Environmental Disturbances

Among the promising application of autonomous surface vessels(ASVs)is the utilization of multiple autonomous tugs for manipulating a floating object such as an oil platform,a broken ship,or a ship in port areas.Considering the real conditions and operations of maritime practice,this paper proposes a multi-agent control algorithm to manipulate a ship to a desired position with a desired heading and velocity under the environmental disturbances.The control architecture consists of a supervisory controller in the higher layer and tug controllers in the lower layer.The supervisory controller allocates the towing forces and angles between the tugs and the ship by minimizing the error in the position and velocity of the ship.The weight coefficients in the cost function are designed to be adaptive to guarantee that the towing system functions well under environmental disturbances,and to enhance the efficiency of the towing system.The tug controller provides the forces to tow the ship and tracks the reference trajectory that is computed online based on the towing angles calculated by the supervisory controller.Simulation results show that the proposed algorithm can make the two autonomous tugs cooperatively tow a ship to a desired position with a desired heading and velocity under the(even harsh)environmental disturbances.

Environmental Lead and Nickel Contamination of Tank Rainwater in Esperance, Western Australia: An Evaluation of the Cleaning Program

A significant number of birds in the port town of Esperance, Western Australia died in the summer of 2006/2007 and elevated lead levels were found in the kidneys, livers and brains of autopsied birds. These elevated lead levels alerted Government authorities to investigate the public health impacts of potential lead contamination in the community resulting from transport of lead carbonate from the Esperance Port. Water samples from domestic rainwater collection systems were collected to determine the extent of heavy metal contamination;19% and 24% of tanks had lead and nickel levels above the Australian Drinking Water Guidelines. The aim of this study was to evaluate whether cleaning of rainwater tanks had reduced exposure to lead and nickel contamination in the community. Follow-up sampling of 176 tanks across Esperance indi-cated that that there had been reductions in both lead and nickel concentrations, but that the reduction has been greater for nickel concentrations. The reduction in nickel concentration was significantly associated with cleaning status, whereas this was not the case for lead. Proximity to the Esperance Port was an impor-tant determinant of lead concentration. Tank and roof characteristics did not significantly influence the fol-low-up lead concentrations. The results suggested that there was ongoing contamination of rainwater tanks from the environment.

The Impact of Shipping Accidents on Marine Environment in Albanian Seas

Shipping accidents are unexpected events that result in financial loss and properties,damages and either loss of people.Several reasons as human errors,technical failures,natural conditions,shipping factors,route conditions and cargo related factors play role in these accidents.Unfortunately,shipping accidents are inevitable cases of maritime field,in contravention of creative and innovative technologies in shipping sector and execution of precautionary safety rules and regulations.Marine accidents adversely affect the human,the marine environment,properties and activities aboard ships and ashore in various forms and degree of extent.The effects of accidents vary from minor injuries to fatalities and from insignificant damage to very severe damage to the environment and property.The cost of accidents,including fatalities and injuries,damage to property and the environment,prevention and mitigating measures,and insurance accounts for a considerable share of transport costs.Main purpose of this paper is to investigate the effects of shipping accidents on marine environment in Albanian Seas.Within this scope firstly,the literature related shipping accidents and marine environment were handled.Then,the statistics of shipping accidents and marine environment in Albanian Seas were analyzed.Finally,future projections were provided in the light of presented matters and current developments.

基于虚拟现实的船舶航行复杂周围环境图像三维仿真

为提升船舶在复杂航行环境中的安全,提出基于虚拟现实的船舶航行复杂周围环境图像三维仿真方法。该方法使用虚拟现实技术中的Vega Prime虚拟现实开发工具,依据海洋、船舶相关数据与图像,使用Crertor工具建立flt静态三维模型库,从该模型库内导出船舶三维模型所需数据后,使用Vega Prime虚拟现实开发工具的LynXPrime图形界面,对船舶航行复杂周围环境的水体、海浪等进行建模并进行纹理制作后,再通过实时驱动、视景仿真驱动以及仿真交互程序运行,实现船舶航行复杂周围环境图像三维仿真模型的交互。实验结果表明,该方法可有效对船舶航行复杂周围环境的洋流流向、流速、海水温度进行三维仿真。同时也可对船舶航行环境内其他船舶进行红外视景可视化,且应用效果较佳。

Investigation of formaldehyde sources and its relative emission intensity in shipping channel environment

Formaldehyde(HCHO)is considered one of the most abundant gas-phase carbonyl compounds in the atmosphere,which can be directly emitted through transportation sources.Long-Path Differential Optical Absorption Spectroscopy(LP-DOAS)was used to observe HCHO in the river channel of Wusong Wharf in Shanghai,China for the whole year of 2019.Due to the impact of ship activity,the annual average HCHO level in the channel is about2.5 times higher than that in the nearby campus environment.To explain the sources of HCHO under different meteorological conditions,the tracer-pair of CO and O_(x)(NO_(2)+O_(3))was used on the clustered air masses.The results of the source appointment show that primary,secondary and background account for 24.14%(3.34±1.19 ppbv),44.78%(6.20±2.04ppbv)and 31.09%(4.31±2.33 ppbv)of the HCHO in the channel when the air masses were from the mixed direction of the city and channel,respectively.By performing background station subtraction at times of high primary HCHO values and resolving the plume peaks,directly emitted HCHO/NO_(2)in the channel environment and plume were determined to be mainly distributed between 0.2 and 0.3.General cargo ships with higher sailing speeds or main engine powers tend to have higher HCHO/NO_(2)levels.With the knowledge of NO_(2)(or NO_(x))emission levels from ships,this study may provide data support for the establishment of HCHO emission factors.

基于单片机技术的无人船湿地环境监测系统设计

针对当前湿地环境监测工作耗时耗力、安全系数低、成本高和采样难度大的问题,提出基于STC89C52RC和HC-12的无人船湿地环境监测系统。系统以STC89C52RC单片机为主控单元,使用便携式移动电源供电,通过导线连接由nRF905无线通信模块、HC-12无线通信模块、电机驱动系统、舵机驱动系统、水样采集系统、全球定位系统(global position system,GPS)和水质指标监测系统等构成的湿地环境监测无人船系统硬件部分,通过串口分别连接和烧写使用C#、keil软件制作上位机程序与nRF905单片机驱动程序,实现计算机通过串口通信方式完成单片机之间的无线通信和AT指令集的收发,从而达成计算机远距离实时遥控无人船进行定点水样采集与pH、浊度、温度指标监测的目的。野外实验结果证明,系统运行稳定,且水质指标测定结果精准。

极地船舶直升机综合保障方法研究

为满足我国日益增加的极地船舶航空保障需求,有必要提出1套符合极地低温、结冰等极端环境条件下的船舶航空保障方法。该文通过对现行常用极地规范、标准及实船配置的研究,分析其与极地极端环境不相称之处,并借鉴国内外相关系统,提出针对性的改进方案。这些改进后的极地船舶航空保障方法,可有选择性地应用于未来极地船舶的设计和建造中。

港航环境管理机制与综合评价研究

为了促进港航行业可持续发展,加快向环境友好型港口转变,提出港航环境管理机制的框架,从管理能力、防污工作和现状反馈3个维度,构建港航环境管理综合评价指标体系。结合德尔菲法、层次分析法和模糊数学等理论方法,建立模糊层次综合评价模型,并对浙江沿海港航环境管理体系进行评价。结果表明,浙江沿海港航环境管理体系属于良好范畴,浙江沿海港航环境管理仍有提升空间。同时,根据各项指标的权重大小,提出相应改善措施和建议,对港航环境管理具有一定的借鉴作用。

无人船走航监测技术在地表水环境监测中的应用

地表水环境监测是生态环境保护监督管理的一项基础工作,通常采用手工监测和自动监测两种形式。无人船走航监测作为一种新型技术手段,目前已在地表水监测中有一定的应用。本文首先开展无人船走航监测技术分析,然后选取某国控断面所在水域开展无人船走航监测,最后指出无人船走航监测存在的问题。随着无人船走航监测技术的不断发展和环境保护资金的投入,无人船走航监测将逐步成为一种可靠便捷的技术手段,为地表水环境治理提供可靠数据支撑。

电动和混合动力船舶减排核算研究及应用

聚焦于电动与混合动力船舶的温室气体减排量核算方法及其节能减排的潜力,通过构建核算方法模型,明确定义基准线情景和项目情景,对各年度的基准线排放量、项目排放量、泄漏排放量和项目减排量进行详细计算,深入分析了项目的减排效果、可持续性和环境贡献。结果表明:①减排效果显著,计入期内的合计减排量达到14 781.09 t,平均年减排量达到1 478.11 t;②可持续性较高,项目排放量和项目减排量呈现逐年递减的趋势,同时仍保持在相对较高水平;③环境贡献显著,项目的减排量占基准线排放量的比例每年都在50%以上,最高达到80%以上。研究成果可为温室气体减排量核算提供参考,有助于推动营运船舶领域的绿色低碳发展。

渤海边际油田延长测试新模式设计与应用

为进一步评价产能,落实地质储量规模及潜山底水水体大小,降低油藏开发风险,在渤海某油田勘探评价井的基础上采用延长测试的方式进行勘探开发一体化评价。结合该井的地理位置及作业特点,创新使用“作业支持平台+环保船转运”的模式开展施工。在作业支持平台上搭建延长测试生产流程,并设置临时储油装置,利用外输软管将原油外输至环保船上,多条环保船轮流转运至生产平台,在摸清油藏动态生产规律的同时,回收作业成本。该模式流程简单、灵活快捷、成本低,是渤海边际油田延长测试作业模式的又一次探索和创新,具有借鉴意义。

Adaptive back-stepping control on container ships for path following

A feedback-dominance based adaptive back-stepping(FDBAB) controller is designed to drive a container ship to follow a predefined path. In reality, current, wave and wind act on the ship and produce unwanted disturbances to the ship control system.The FDBAB controller has to compensate for such disturbances and steer the ship to track the predefined(or desired) path. The difference between the actual and the desired path along which the ship is to sail is defined as the tracking error. The FDBAB controller is built on the tracking error model which is developed based on Serret-Frenet frame transformation(SFFT). In additional to being affected by external disturbances, the ship has more outputs than inputs(under-actuated), and is inherently nonlinear.The back-stepping controller in FDBAB is used to compensate the nonlinearity. The adaptive algorithms in FDBAB is employed to approximate disturbances. Lyapunov's direct method is used to prove the stability of the control system. The FDBAB controlled system is implemented in Matlab/Simulink. The simulation results verify the effectiveness of the controller in terms of successful path tracking and disturbance rejection.

Train-the-Trainer Course on Energy Efficient Operation of Ships

The International Maritime Organization (IMO) expanded, in 2011, its air emissions control regulations by encouraging energy efficiency and added them to MARPOL Annex VI. To assist national implementation of these new regulations, the IMO-KOICA partnership sponsored the development of a Train-the-Trainer (TTT) project on energy efficient operation of ships. The first project objective was to develop a comprehensive training package, which covers company policy and shipping contracts, port/ship interaction, ship technical solutions and day-to-day ship management. The second objective was to enhance capacity building in developing countries by creating a pool of instructors able to raise awareness in their respective regions using the dedicated training material. During each session, pedagogic support tools backed the content delivery. Forty-one participants from thirty-two countries attended two sessions of the TTT course. The TTT training formula, blending content and pedagogics, demonstrated its efficiency by committing and challenging each participant during the entire course. The outcome of the final day assessment showed that participants captured the essence of the issues and were able to absorb the basics of pedagogy to support the distribution of the training content and spread awareness. Know-how gained through TTT will contribute to the advancement of knowledge in promoting sustainable maritime transport development as advanced by the IMO. It is the authors’ strong belief that the way that the TTT course is designed, developed and delivered provides unique benefits for the participants and their countries.

季节因素对二冲程船用柴油机性能参数及排放影响研究

In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine environment.However,these factors are typically neglected,or their consequences are deemed to have little effect on machinery,the environment,or human life.In this study,seasonal air&seawater temperature effects on marine diesel engine performance parameters and emissions are investigated by using a full-mission engine room simulator.A tanker ship two-stroke main engine MAN B&W 6S50 MC-C with a power output of 8600 kW is employed during the simulation process.Furthermore,due to its diverse risks,the Marmara Region is chosen as the application area for real-time average temperature data.Based on the research findings,even minor variations in seasonal temperatures have a significant influence on certain key parameters of a ship’s main engine including scavenge pressure,exhaust temperatures,compression and combustion pressures,fuel consumption,power,and NOx-SOx-COx emissions.For instance,during the winter season,the cylinder compression pressure(pc)is recorded at 94 bar,while the maximum pressure(pz)reaches 110 bar.In the summer,pc experiences a decrease of 81 bar,while pz is measured at 101 bar.The emission of nitrogen oxides(NOx)exhibits a measurement of 784 parts per million(ppm)during winter and 744 in summer.The concentration of sulfur oxides(SOx)is recorded at 46 ppm in winter and 53 in summer.Given the current state of global warming and climate change,it is an undeniable fact that the impact of these phenomena will inevitably escalate.

政府环境规制下港航系统减排演化博弈研究

针对碳达峰目标下我国港航系统的减排问题,通过构建地方政府、港口和航运公司三方主体参与的港航系统环境规制演化博弈模型,系统分析三方主体的策略选择过程与整体演化稳定性,阐明港航系统内各主体演化趋势的驱动机理。并通过数值仿真分析,讨论三方主体初始策略和地方政府不同奖惩监管机制下港航系统的策略选择。研究结果表明,地方政府主动监管策略的选择与港口和航运公司的低积极减排意愿有关;港口和航运公司积极减排策略的演化速率与彼此的意愿成正比;地方政府在静态奖惩监管机制下,对惩罚强度的调整不影响港口和航运公司的积极减排策略,但低补贴强度会导致两者的消极减排;静态监管机制下,地方政府仅有(高补贴,无惩罚)的单一策略可以使港口和航运公司达成(积极减排、积极减排)的演化均衡;动态监管机制下,地方政府采取(低动态补贴,高静态惩罚)的混合监管策略能够以低成本实现港航系统积极减排策略的演化均衡。

中型邮轮舱室绿色阻燃室内装饰材料与设计

基于中型邮轮舱室对绿色阻燃室内装饰材料的应用及设计需求,开展了一系列的研究和分析。针对常用的邮轮舱室装饰材料,详细分析了其阻燃和环保特性,比较了各种材料的性能,从而选取出性能优越的绿色阻燃材料。在材料设计方面,考虑到邮轮舱室的特殊环境因素,提出了一种新的材料配比和加工方法,对绿色阻燃材料进行了优化设计。同时,通过对装饰材料的阻燃性能进行检测和模拟分析,验证了设计的有效性。此外,还对邮轮舱室的绿色阻燃设计提出了一系列具体要求,为邮轮舱室的防火设计提供了重要参考。经过全面研究,得出结论:采用设计的绿色阻燃装饰材料,不仅可以提高邮轮舱室的防火安全性,而且可以满足环保要求,提高旅客的乘船体验。

Decarbonizing in Maritime Transportation: Challenges and Opportunities

As global warming caused by greenhouse gases grows (GHGs) into a global environmental threat, carbon dioxide emissions are drawing increasing attention in these years. Among all emission sources, transportation is a major contributor to climate change because of its high dependence on fossil fuels. The International Maritime Organization (IMO) has therefore been promoting the reduction of fuel usage and carbon emissions for container ships by such measures as improving shipping route selection, shipping speed optimization, and constructing clean energy propulsion systems. In this paper, a review of the impact of carbon dioxide emissions on climate change is presented;the current situations of carbon dioxide emissions, decarbonizing methods, IMO regulations, and possible future directions of decarbonizing in the maritime transportation industry are also discussed. Based on the result, it is found that in the case that non intelligent ships still occupy the vast majority of operating ships, the use of new energy as the main propulsion fuel has the defects of high renewal cost and long effective period. It is more likely to achieve energy conservation and emission reduction in the shipping industry in a short period of time by using intelligent means and artificial intelligence to assist ship operation. .