System-of-Systems Modeling and Simulation of a Ship Environment With Wireless and Intelligent Maintenance Technologies

Modeling and simulation environments are needed to support decision making in Navy Warfighters, which are emergent systems that pose a challenge to operations management. Ships consist of complex interconnected systems such as the infrastructure, crew, and workflow. A system-of-systems approach using agent-based modeling is applied here to develop workflow simulations involving a ship's crew conducting routine maintenance, watch duty, and reporting functions. Simple models are used to describe basic behavioral traits and intelligence in crew members; machinery including sensors for intelligent maintenance; equipment consuming power; mobile and stationary communication network access points; models for data transfer over the network; crew mobility models; power distribution and trimming models for the electrical system; and a fire model to simulate emergency scenarios. The simulation results demonstrate an increase in machine availability due to the implementation of intelligent maintenance systems. The effects of wireless-network usage on crew resource utilization and overall ship capability in normal operational scenarios are also demonstrated. A simple rescheduling algorithm is used to improve crew utilization and estimate manning requirements. The effects of emergency scenarios such as fires in different locations are also studied. Sensitivity analysis is presented to verify the developed model, and a note on validation is given.     

粒子群算法在多船避碰决策中的应用

多船避碰是船舶避碰中最复杂的问题,也是船舶自动避碰方法研究中的难点之一.对许多学者的多船避碰研究进行分析,将最近会遇距离DCPA、最近会遇时间TCPA、两船距离、相对距离、本船转向角等作为基本评判参数,利用雷达进行一系列的观测,获得避让要素,建立碰撞危险度的评价模型.应用粒子群算法找出最优的解决方案,得出最优转向避碰幅度解.该方法不仅有助于解决多船会遇情况下的本船最优转向角度值,而且也有助于多船避碰决策系统的智能化设计与开发.     

船舶狭小空间虚拟人维修姿态建模技术

针对现有虚拟人仿真技术在船舶狭小空间维修作业中存在的效率低下、需要较多人工干预、仿真成本高等问题,提出一种虚拟人姿态混合建模仿真技术。根据狭小空间中人体维修作业的特点,将虚拟人姿态建模分为虚拟人躯干及下肢姿态建模与虚拟人手臂姿态建模两部分。首先,提出一种基于姿态库的狭小空间姿态自动匹配算法,以确定虚拟人在狭小空间中的操作位置与姿态;在此基础上,建立多目标优化模型对手臂姿态进行求解,并实现维修仿真姿态的生成。以某型船舶机舱罐体阀门维修为例的实验结果表明,所提方法可以实现虚拟人姿态的自动定位与生成,且可有效提高维修仿真效率。     

虚拟环境的系统设计方法及计算模型研究

面向对象技术和面向Ａｇｅｎｔ技术是虚环境系统的基本设计方法。本文用面向对象的方法来构造Ａｇｅｎｔ,并提供一组支撑Ａｇｅｎｔ的底层计算模型,如神经网络,遗传算法,专家系统和规划管理等。     

一种本安型有水信号传感器设计

为了在恶劣的舱底环境下安全、可靠地检出船舶进水情况,设计了一种本安型有水信号传感器。根据船舶应用的特点和传感器的工作环境,确定传感器类型和防爆形式,并设计传感器外形。根据传感器的物理特性和工作特性,计算传感器参数,并进行本质性能评定。试验验证表明:设计参数与实测值基本一致,可满足船舶蓄电池舱防爆等级的要求。该传感器已经广泛应用于各型船舶,并取得了良好的效果。     

基于LabVIEW的船用发电机特性试验测试系统

造船厂新造的每一只船在出厂前都要对船上发电机进行性能特性试验，其中一项就是突卸和突加负载特性试验，要求显示试验过程中电压，频率的变化过程。介绍了Lab VIEW虚拟仪器在测试过程中的应用，包括硬件连接、软件编制，最后给出实际测试过程中得到的波形。     

突发公共卫生事件的应急响应服务系统的分析与设计

阐述了贵州省疾病控制和预防中心目前阶段的工作成绩和存在的问题。在此基础上,设计了基于传染病学时空传播模型的突发公共卫生事件的应急响应服务系统。系统通过以事件驱动的服务动态整合机制,联合调度分布式的多种信息资源,进行多部门协同办案,为公共安全应急管理体系的建设提供了良好的技术支撑。     

基于LabVIEW的远洋测量船监控系统

出于提高测量船监控系统信息化水平,及消除岸船间信息壁垒的目的,开发以以太网为传输媒介的测量船监综合控系统。鉴于测量船各类设备的特性,选用LabVIEW平台开发该监控系统。测量船监控系统采用分布式发布,集中式存储,选择式接收的策略,使系统可靠性、网络数量流量均达到最优。根据测量船设备现状,提出四种数据采集方法与四种网络通信手段,将目前各类监控设备有机的结合在一起,既提升了监控的信息化水平,又有效保护已有投资,降低开发成本。     

基于NAPA的型线变换研究

NAPA作为一款开发成熟的船舶设计软件,在初步设计和详细设计方面有着相当强大的功能。型线变换又是船舶设计过程中一个必不可少的环节,对船舶性能起着举足轻重的影响。该文对NAPA的型线变换模块进行了分析,针对作者对NAPA的理解,结合例子给出了直观的介绍。     

基于归一化灰度Hough变换的SAR图像舰船尾迹检测算法

舰船尾迹检测作为近年来SAR图像海洋应用的一个重要方面而受到关注。目前大多数研究都是利用Radon变换作为数学工具，结果得到增强的是尾迹特征，而不是尾迹的端点。从提取尾迹的端点坐标出发，在传统Hough变换算法基础上进行改进，提出了基于归一化灰度Hough变换的SAR图像舰船尾迹检测算法，并推导出尾迹端点反演算法，同时自动提取舰船的航速，取得了较好的实验结果。     

VU-flow: a visualization tool for analyzing navigation in virtual environments

This paper presents a tool for the visual analysis of navigation patterns of moving entities, such as users, virtual characters or vehicles in 3D virtual environments (VEs). The tool, called VU-Flow, provides a set of interactive visualizations that highlight interesting navigation behaviors of single or groups of moving entities that were the VE together or separately. The visualizations help to improve the design of VEs and to study the navigation behavior of users, e.g., during controlled experiments. Besides VEs, the proposed techniques could also be applied to visualize real-world data recorded by positioning systems, allowing one to employ VU-Flow in domains such as urban planning, transportation, and emergency response     

Sensor fault masking of a ship propulsion system

This paper presents the results of a study on fault-tolerant control of a ship propulsion benchmark [Izadi-Zamanabadi, R., & Blanke, M. (1999). A ship propulsion system as a benchmark for fault tolerant control. Control Engineering Practice, 7 (2), 227–239] which uses estimated or virtual measurements as feedback variables. The estimator operates on a self-adjustable design model so that its outputs can be made immune to the effects of a specific set of component and sensor faults. The adequacy of sensor redundancy is measured using the control reconfigurability [Wu, N. E., Zhou, K., & Salomon, G. (2000). Reconfigurability in linear time-invariant systems. Automatica, 36 (11), 1767–1771] and the number of sensor based measurements are increased when this level is found inadequate. As a result, sensor faults that are captured in the estimator's design model can be tolerated without the need for any reconfiguration actions. Simulations for the ship propulsion benchmark show that, with additional sensors added as described and the estimator in the loop, satisfactory fault-tolerance is achieved under two additive sensor faults, an incipient fault, and a parametric fault, without having to alter the original controller in the benchmark.     

基于虚拟仪器的舰船腐蚀电场仿真系统

舰船处于海洋中不可避免产生腐蚀,为防止腐蚀,舰船上采用阴极保护系统,从而由阴极保护系统就产生腐蚀静电场和轴频电场,这种腐蚀电场给舰船安全带来威胁,为此提出基于虚拟仪器的舰船腐蚀电场仿真系统。虚拟仪器具有效率高,性能好,控制灵活,精度高等特点,为此仿真系统采用PXI总线仪器和LabVIEW7．1可视化的虚拟仪器系统开发平台,把传统仪器的所有功能模块集成在一台计算机中,用户可以通过修改虚拟仪器的软件改变其功能与规模。舰船腐蚀电场仿真系统实现了腐蚀电场信号的自动采集,并通过仿真系统的计算机进行电场信号的处理和分析。仿真结果表明,腐蚀静电场与阴极保护系统的电极位置有关,而轴频电场产生与阴极保护系统的电流有关,轴频电场的频率与螺旋浆的转速成一定比例。     

变结构控制在船舶操纵中的应用

本文根据船舶操纵系统的具体特点，为限制水域中的船舶操纵提供了一种变结构控制方案，同时考虑了航向纠编和航迹调整。根据一种特定航道设计的变结构控制系统可适用于一定范围内的其他航道内的船舶操纵，且控制精度高，无抖振发生。     

利用Simulink实现船舶运动的虚拟现实

该文建立了某型船平面操纵运动的Simulink的仿真模型，并利用虚拟现实工具箱(virtusl reality toolbox)实现了对船舶运动的虚拟现实，这有利于我们了解和研究船舶的一些极限运动(比如，可能导致倾覆的参数激振、横甩等)的机理。     

Hybrid MCDM based methodology for selecting the optimum maintenance strategy for ship machinery systems

The key to achieving optimum ship system reliability and safety is to have a sound maintenance management system in place for mitigating or eliminating equipment/component failures. Maintenance has three key elements; risk assessment, maintenance strategy selection and the process of determining the optimal interval for the maintenance task. The optimisation of these three main elements of maintenance is what constitute a sound maintenance management system. One of the challenges that marine maintenance practitioners are faced with is the problem of maintenance selection for each equipment item of the ship machinery system. The decision making process involves utilising different conflicting decision criteria in selecting the optimum maintenance strategy from among multiple maintenance alternatives. In tackling such decision making problems the application of a multi-criteria decision making (MCDM) method is appropriate. Hence in this paper two hybrid MCDM methods; Delphi-AHP and Delphi-AHP-PROMETHEE, are presented for the selection of appropriate maintenance strategies for ship machinery systems and other related ship systems. A case study of a ship machinery system maintenance strategy selection problem is used to demonstrate the suitability of the proposed methods.     

基于虚拟柴油发电机控制策略的岸电电源设计

岸电电源需要与各种类型的船舶电源系统进行无缝切换,而传统的基于虚拟同步发电机控制策略的岸电电源只能模拟同步发电机的机械特性,与船舶的主电源——柴油发电机还略有差异。因此并网运行常出现大的超调和低频振荡等问题。针对这些问题,首先对柴油发电机(DG)和传统的虚拟同步发电机控制进行建模分析,然后针对DG动态响应速度慢、电压频率易波动的问题,提出了虚拟柴油发电机控制策略。该控制策略利用补偿网络的惯性抑制了频率的波动,微分环节提高系统的动态特性。最后,建立一套100kVA岸电电源系统样机系统,试验结果验证了该控制方法的有效性。     

基于虚拟柴油发电机控制策略的岸电电源设计

岸电电源需要与各种类型的船舶电源系统进行无缝切换,而传统的基于虚拟同步发电机控制策略的岸电电源只能模拟同步发电机的机械特性,与船舶的主电源——柴油发电机还略有差异。因此并网运行常出现大的超调和低频振荡等问题。针对这些问题,首先对柴油发电机(DG)和传统的虚拟同步发电机控制进行建模分析,然后针对DG动态响应速度慢、电压频率易波动的问题,提出了虚拟柴油发电机控制策略。该控制策略利用补偿网络的惯性抑制了频率的波动,微分环节提高系统的动态特性。最后,建立一套100kVA岸电电源系统样机系统,试验结果验证了该控制方法的有效性。     

Using virtual environments to train firefighters

Using virtual environments for training and mission rehearsal gives US Navy firefighters an edge in fighting real fires. A test run on the ex-USS Shadwell measured the improvement. The results suggest that virtual environments serve effectively for training and mission rehearsal for shipboard firefighting. VE training provides a flexible environment where a firefighter can not only learn an unfamiliar part of the ship, but also practice tactics and procedures for fighting a fire by interacting with simulated smoke and fire without risking lives or property. These tests proved a successful first step in developing a new training technology for shipboard firefighting based on immersive virtual environments. The tests also indicated potential areas for improvement, requiring additional research. User interaction techniques for manipulating objects in VEs need further study, along with usability studies to determine their effectiveness or utility. Other areas that could enhance VE training systems include more natural and intuitive I/O devices such as 3D sound, speech and natural language input, integrated multimedia and hypermedia instruction, and multi user interaction     

新型船用电子应急车令设计方案介绍

船用电子应急车令,是应用于船舶的一种驾驶控制的电子通信设备,它是船上驾驶室主控车令控制器的备份控制设备,可以通过车令命令向“机舱”和“集控室”发出指令,使船舶在任何情况下正常行驶。进入90年代以来,各类大中型船舶上纷纷要求安装应急车令系统,以保证船只在航行中的绝对安全,所以电子应急车令系统在这种情况下应运而生且发展迅速。