The design and commissioning of a fully elastic model of a uniform container ship

Experimental hydroelasticity has not followed the rapid evolution of its computational counterpart. Hydroelastic codes have changed significantly in the past few decades, moving to more detailed modelling of both the structure and the fluid domain. Physical models of ships are, even today, manufactured with a very simplified structural arrangement, usually consisting of a hollow rectangular cross section. Appropriate depiction of the internal structural details ensures that properties relevant to antisymmetric vibration are scaled accurately from the real ship to the model. Attempts to create continuous, ship-like structures had limited success, as manufacturing constraints did not allow for much internal structural detail to be included. In this investigation, the first continuous model of a ship with a detailed internal arrangement resembling a container ship is designed, produced using 3D printing and tested in waves. It is demonstrated that the global responses of the hull in regular head waves agree well with theory and past literature, confirming that such a model can represent the behaviour of a ship. Furthermore, it is found that the model is capable of capturing local responses of the structure, something that would be impossible with “traditional” hydroelastic ship models. Finally, the capability of the model to be used to investigate antisymmetric vibrations is confirmed. The methodology developed here opens a whole new world of possibilities for experiments with models that are tailored to the focus of the investigation at hand. Moreover, it offers a powerful tool for the validation of modern state-of-the-art hydroelastic codes. Ultimately, it creates the next step in the investigation of dynamic responses of ship structures, which contribute significantly to accumulating damage of the hull. Better understanding of these responses will allow designers to avoid over-engineering and use of big safety factors to account for uncertainties in their predictions.     

200kN.m扭矩标准装置智能管理系统研究

随着国际工业和智能化的快速发展,大扭矩测量和校准技术需求越来越迫切。上海船舶设备研究所成功研制了国内首台大扭矩标准装置,解决了工业部门对大扭矩标准装置的迫切需求,该装置达到了国际领先水平。文章以一种大型扭矩标准装置智能管理系统的研究工作出发,介绍了静重式大扭矩标准装置电气控制系统的原理、组成、功能、控制软件和组态软件的设计要点等,为200kN.m扭矩高准确度量值传递提供了技术手段。文章为扭矩专业的计量和测试人员提供了静重式大扭矩标准装置控制系统和组态软件系统设计的技术指导。     

A network level connectivity robustness measure for connected vehicle environments

This study introduces a new CONnectivity ROBustness model (CONROB) to assess vehicle-to-vehicle communication in connected vehicle (CV) environments. CONROB is based on Newton’s universal law of gravitation and accounts for multiple factors affecting the connectivity in CV environments such as market penetration, wireless transmission range, spatial distribution of vehicles relative to each other, the spatial propagation of the wireless signal, and traffic density. The proposed methodology for the connectivity robustness calculation in CONROB accounts for the Link Expiration Time (LET) and the Route Expiration Time (RET) that are reflected in the stability of links between each two adjacent vehicles and the expiration time of communication routes between vehicles. Using a 117 sq-km (45-square mile) network in Washington County, located west of Portland city, Oregon, a microscopic simulation model (VISSIM) was built to verify CONROB model. A total of 45 scenarios were simulated for different traffic densities generated from five different traffic demand levels, three levels of market penetration (5%, 15%, and 25%), and three transmission range values [76 (250), 152 (500), and 305 (1000) m (ft)]. The simulation results show that the overall robustness increases as the market penetration increases, given the same transmission range, and relative traffic density. Similarly, the overall connectivity robustness increases as the relative traffic density increases for the same market penetration. More so, the connectivity robustness becomes more sensitive to the relative traffic density at higher values of transmission range and market penetration. Multiple regression analysis was conducted to show the significant effect of relative traffic density, transmission range, and market penetration on the robustness measure. The results of the study provide an evidence of the ability of the model to capture the effect of the different factors on the connectivity between vehicles, which provides a viable tool for assessing CV environments.     

Exploring the impact of connected and autonomous vehicles on freeway capacity using a revised Intelligent Driver Model

ABSTRACT

Connected and autonomous vehicle (CAV) technologies are expected to change driving/vehicle behavior on freeways. This study investigates the impact of CAVs on freeway capacity using a microsimulation tool. A four-lane basic freeway segment is selected as the case study through the Caltrans Performance Measurement System (PeMS). To obtain valid results, various driving behavior parameters are calibrated to the real traffic conditions for human-driven vehicles. In particular, the calibration is conducted using genetic algorithm. A revised Intelligent Driver Model (IDM) is developed and used as the car-following model for CAVs. The simulation is conducted on the basic freeway segment under different penetration rates of CAVs and different freeway speed limits. The results show that with an increase in the market penetration rate, freeway capacity increases, and will increase significantly as the speed limit increases.     

铁路槽罐车智能监测系统的设计

针对铁路槽罐车运输过程中仍需企业员工随车押运,存在无法准确掌握货物状态、出现紧急情况不能发现、随车押运条件艰苦等诸多问题,提出了铁路槽罐车智能监测系统,实现了列车押运的自动化、无人化、远程化,使传统押运模式得到极大改善.     

中韩造船业国际竞争力对标分析

为迎接全球船舶行业面临的世界经济发展停滞和船海市场需求不足带来的严峻挑战,全面对标分析中国造船企业与世界一流的韩国造船企业之间的差距。对比2020年中韩造船三大指标和主要船型建造的实动工时与关键周期数据,对中韩造船企业在设计、生产、管理等三大方面的精细化、标准化、机制模式等关键性问题进行对标分析,找出原因并提出解决问题的建议。中国造船业应积极开展常态化、精细化的对标工作,准确研判新发展格局带来的新机遇、新挑战,明确主攻方向,聚焦关键环节,找准融入新发展格局的着力点和突破口。     

Analysis of a cooperative variable speed limit system using microscopic traffic simulation

Variable speed limit systems where variable message signs are used to show speed limits adjusted to the prevailing road or traffic conditions are installed on motorways in many countries. The objectives of variable speed limit system installations are often to decrease the number of accidents and to increase traffic efficiency. Currently, there is an interest in exploring the potential of cooperative intelligent transport systems including communication between vehicles and/or vehicles and the infrastructure. In this paper, we study the potential benefits of introducing infrastructure to vehicle communication, autonomous vehicle control and individualized speed limits in variable speed limit systems. We do this by proposing a cooperative variable speed limit system as an extension of an existing variable speed limit system. In the proposed system, communication between the infrastructure and the vehicles is used to transmit variable speed limits to upstream vehicles before the variable message signs become visible to the drivers. The system is evaluated by the means of microscopic traffic simulation. Traffic efficiency and environmental effects are considered in the analysis. The results of the study show benefits of the infrastructure to vehicle communication, autonomous vehicle control and individualized speed limits for variable speed limit systems in the form of lower acceleration rates and thereby harmonized traffic flow and reduced exhaust emissions.     

船舶云制造服务平台及运营模式研究

船舶制造由传统的制造模式向服务化制造的转变是未来船舶制造业的发展趋势。根据船舶制造特点及云制造理念,提出了船舶云制造服务的概念模型和信息模型,设计了船舶云制造的系统结构和云制造服务平台的架构及运营模式,以实现一定区域范围内,船舶制造资源与制造任务间最大限度的快速匹配,实现船舶制造过程和管理的服务化、集约化。     

南通市港口货物集散运输控制方案的设计与研究

文章从交通工程学的角度,分析了南通港口运输目前的现状,以智能交通调度为指导思想,提出了一套合理、经济的港口大交通控制方案。该方案配合铁路、公路和管道运输,将货物合理分配到各种运输方式中,使南通市各个港口到不同货物中转站的交通更畅通、高效、安全。该方案的实施将有利于南通在长江三角洲地区“中心两翼”型合理运输格局的形成．具有较高的实用价值。     

公路收费站横杆状态的视频检测方法及应用

以高速公路收费站监控视频为背景,提出一种可自动分析和检测横杆运行状态的方法,从而判断车辆通过与否并统计车辆数。该方法的实现,首先对横杆的颜色特征和轮廓几何特征进行学习;然后对监控视频图像进行颜色和几何特征匹配以滤除非横杆区域;再对得到的疑似横杆区域进行修复;最后计算横杆的重心坐标及其运动状态以判断开闭状态。样本测试显示,新方法能有效克服视频场景中各种干扰因素的影响,提高车辆计数的准确性。