船舶电站双机并联系统的新型控制器研究

基于离散滑模控制理论设计了船舶电站双机并联系统的稳定和有功分配控制器。分析了变速趋近律的运动机理并给出了一种改进算法,通过引入衰减系数以加快趋近速度。只要不确定因素有界,即可保证闭环系统的鲁棒稳定性。通过调整变速趋近律自身参数,可以避免抖振并使系统具有良好的动态品质。仿真结果表明了本文方法的有效性。     

一种DVSC设计方法在舰船航向控制中的运用

运用变结构的理论和设计方法对舰船航向的问题进行离散变结构设计，对准滑动模态的存在条件进行了分析和研究，运用基于离散变速趋近律的变结构控制设计方法对舰船航向进行了研究和设计，运用仿真证明了设计的有效性。     

基于趋近律方法的永磁同步电机滑模速度控制器设计

为了提高永磁同步电机(permanent magnet synchronous motor,PMSM)调速系统的动态品质,提出了一种基于趋近律方法的滑模速度控制策略。为了解决传统指数趋近律所存在的缺点,文中首先设计了一种改进的指数趋近律算法,该方法能够根据系统状态距离平衡点的远近而自适应调整趋近律速度;基于改进的指数趋近率设计了适用PMSM调速系统的速度滑模控制器。通过仿真结果验证了所提控制算法的有效性和可行性。     

模糊离散变结构控制及在直流伺服系统中的应用

研究基于趋近律方法的离散变结构控制设计问题。提出一种新的趋近律,可以稳定于原点;并与模糊调节技术相结合设计了扰动估计器。将所提方法用于直流伺服系统的控制,仿真研究结果表明,所设计的控制器可以有效减弱抖振,并使伺服系统具有良好的跟踪能力和很强的鲁棒性。     

基于Bech模型的船舶航向离散变结构控制

采用带不确定项的Bech模型可以更好地反映船舶运动的非线性特性以及不确定因素对船舶运动的影响。在Bech模型中增加不确定项，采用离散变结构控制理论设计船舶航向控制器。针对传统设计方法稳态抖振的缺点，提出一种新型的离散趋近律，可以消除传统趋近律自身参数导致的抖振。设计扰动估计器，能够自适应估计不确定因素对系统的影响，只要不确定因素的变化率有界，即可保证闭环系统的鲁棒稳定性，特别是对于幔变不确定性，具有很高的估计精度。仿真结果表明，所设计的离散变结构控制器可以快速准确地跟踪设定航向，并对参数摄动和外部干扰具有很强的鲁棒性。     

基于输入输出线性化的航迹滑模控制及仿真

针对船舶航迹控制系统的非线性及易受外部干扰的特点,提出了一种基于输入输出线性化的航迹滑模控制策略。通过定义输出变量将非线性航迹控制系统转化为线性系统,然后采用指数趋近律的滑模控制方法设计控制器,使得设计的非线性控制律直观简洁,鲁棒性好。通过SIMULINK仿真验证了该算法的有效性。     

Finite-time ship formation control based on extended state observer北大核心CSCD

[目的]为了解决大多数船舶编队控制算法控制周期长和时效性差的问题,提出一种基于扩张状态观测器(ESO)的有限时间控制策略。[方法]采用一种非线性终端滑模算法,通过对控制律分区域设计,克服传统终端滑模存在的奇异性问题;将非线性终端滑模与图论结合,实现有限时间的船舶编队控制;利用扩张状态观测器观测并补偿船舶模型中的不确定性及外界的干扰,以保证船舶编队控制的精确性;运用Lyapunov理论验证船舶编队控制律的稳定性。[结果]仿真结果表明,采用所提控制策略使整个编队系统误差在5 s左右趋近于0,从而实现了稳定。[结论]该控制策略能有效控制船舶编队,且控制速度快、时效性好。     

基于趋近律方法的舰载遥控武器站滑模控制研究

本文首先介绍了国内舰载遥控武器站的发展情况,分析了遥控武器站控制系统的优化方向,针对遥控武器站跟踪射击状态下存在的随机扰动问题,设计了一种改进的趋近律,以解决传统趋近律滑模面趋近时间和系统抖振之间的矛盾,提高系统响应快速性。基于改进趋近律设计了适用于舰载遥控武器站控制系统的速度滑模控制器。仿真结果验证了所提控制算法的有效性和可行性,对舰载遥控武器站算法优化具有工程指导意义。     

一种基于直流电站的变速发电技术研究

本文分析了直流电站变速发电系统的组成配置,对变速发电系统进行理论分析,对变速发电控制策略进行研究论证,提出了功率分配和转速调节的控制方法,并通过仿真验证了提出的控制策略的可行性。     

船用锅炉汽包水位内模滑模控制

为进一步提高传统锅炉汽包水位控制系统的响应速度、抗干扰能力和鲁棒性,提出一种基于全程非线性积分滑模面与扰动补偿的内模滑模控制策略。采用内模控制结构补偿时滞对系统的影响,运用滑模控制律提高系统的鲁棒性,设计基于内模控制结构的全程非线性积分滑模面的滑模控制律(Internal Model Control Structure with Global Non-Integral Sliding Mode Control Law,IM-GNISMC),不仅可改善系统的暂态性能,而且能消除滑模趋近阶段,使系统具有全程鲁棒性。由于锅炉汽包水位是积分非自平衡系统,为改善系统的抗干扰能力,并消除阶跃扰动后的稳态误差,设计扰动抑制控制器。进行理论分析和仿真验证,并与三冲量串级比例-积分-微分(Proportional Integral Differential,PID)控制和内模控制相比较。仿真结果表明:设计的控制器具有响应速度快、超调量小和鲁棒性强等特点。     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。