Distributed and Redundant Design of Ship Monitoring and Control Network

The world trend in ship automation is to integrate the monitoring, intelligent control and systematic management of the instruments and equipments both on bridge and in engine room. The paper presents a design scheme of the ship integrated monitoring and operating system based on two layers distributed and redundant computer network. The lower layer network is the field bus network connected mainly by CAN bus; the upper one is the PC local network in TCP/IP protocol, which consisted of a database server, monitoring and operating computers, industrial computers and a set of switches. Distributed schemes are fully applied to both software and hardware. This paper specifically describes the composition, software distribution and redundant technology of the upper local network and gives some important sample codes for the implement of the redundant and distributed design. The technologies here have been proved in the many applications and it may be applied to other industrial fields.     

基于模拟减少集装箱船待港时间的实用方法(英文)

The main challenge for container ports is the planning required for berthing container ships while docked in port.Growth of containerization is creating problems for ports and container terminals as they reach their capacity limits of various resources which increasingly leads to traffic and port congestion.Good planning and management of container terminal operations reduces waiting time for liner ships.Reducing the waiting time improves the terminal’s productivity and decreases the port difficulties.Two important keys to reducing waiting time with berth allocation are determining suitable access channel depths and increasing the number of berths which in this paper are studied and analyzed as practical solutions.Simulation based analysis is the only way to understand how various resources interact with each other and how they are affected in the berthing time of ships.We used the Enterprise Dynamics software to produce simulation models due to the complexity and nature of the problems.We further present case study for berth allocation simulation of the biggest container terminal in Iran and the optimum access channel depth and the number of berths are obtained from simulation results.The results show a significant reduction in the waiting time for container ships and can be useful for major functions in operations and development of container ship terminals.     

A second order volume of fluid （VOF） scheme for numerical simulation of 2-D breaking waves

Among all environmental forces acting on ocean structures and marine vessels, those resulting from wave impacts are likely to yield the highest loads. Being highly nonlinear, transient and complex, a theoretical analysis of their impact would be impossible without numerical simulations. In this paper, a pressure-split two-stage numerical algorithm is proposed based on Volume Of Fluid (VOF) methodology. The algorithm is characterized by introduction of two pressures at each half and full cycle time step, and thus it is a second-order accurate algorithm in time. A simplified second-order Godunov-type solver is used for the continuity equations. The method is applied to simulation of breaking waves in a 2-D water tank, and a qualitative comparison with experimental photo observations is made. Quite consistent results are observed between simulations and experiments. Commercially available software and Boundary Integral Method (BIM) have also been used to simulate the same problem. The results from present code and BIM are in good agreement with respect to breaking location and timing, while the results obtained from the commercial software which is only first-order accurate in time has clearly showed a temporal and spatial lag, verifying the need to use a higher order numerical scheme.     

Adaptive vibration isolation system for diesel engine

An active two-stage isolation mounting, on which servo-hydraulic system is used as the actuator (secondary vibration source) and a diesel engine is used as primary vibration source, has been built. The upper mass of the mounting is composed of a 495 diesel and an electrical eddy current dynamometer. The lower mass is divided into four small masses to which servo-hydraulic actuator and rubber isolators are attached. According to the periodical characteristics of diesel vibration signals, a multi-point adaptive strategy based on adaptive comb filtered algorithm is applied to active multi-direction coupled vibrations control for the engine. The experimental results demonstrate that a good suppression in the effective range of phase compensation in secondary path (within 100Hz) at different operation conditions is achieved, and verify that this strategy is effective. The features of the active system, the development activities carried out on the system and experimental results are discussed in the paper.     

Finite element simplified fatigue analysis method for a non-tubular joint of an offshore jacket platform

This paper proposes the finite element simplified fatigue analysis method for fatigue evaluation of the composite non-tubular joint structure of an offshore jacket subjected to wave loads. The skirt pile sleeve of the offshore jacket, which had been in service, was taken as an example of the non-tubular joint structure. SACS software was used for global analysis of multi-directional wave loads for the jacket platform, and ALGOR software was used to build a finite element model, perform finite element analysis, post-process stress results for acquiring the stress range, and perform fatigue evaluation. The analysis results indicate that the extreme stress range is within the allowable stress range and meets the requirements of DNV code. That means the simplified fatigue analysis method is effective and can be used in fatigue design for the non-tubular joint structure of an offshore jacket.     

Floating production platforms and their applications in the development of oil and gas fields in the South China Sea

This paper studies the current available options forfloating production platforms in developing deepwater oil fieldsand the potential development models of future oil and gasexploration in the South China Sea. A detailed review of currentdeepwater platforms worldwide was performed through theexamples of industry projects, and the pros and cons of eachplatform are discussed. Four types of platforms are currently usedfor the deepwater development： tension leg platform, Spar,semi-submersible platform, and the floating production systemoffloading. Among these, the TLP and Spar can be used for dry treeapplications, and have gained popularity in recent years. The drytree application enables the extension of the drilling application forfixed platforms into floating systems, and greatly reduces the costand complexity of the subsea operation. Newly built wet treesemi-submersible production platforms for ultra deepwater are alsogetting their application, mainly due to the much needed payloadfor deepwater making the conversion of the old drillingsemi-submersible platforms impossible. These platforms have beenused in different fields around the world for different environments;each has its own advantages and disadvantages. There are manychallenges with the successful use of these floating platforms. A lotof lessons have been learned and extensive experience accumulatedthrough the many project applications. Key technologies are beingreviewed for the successful use of floating platforms for fielddevelopment, and potential future development needs are beingdiscussed. Some of the technologies and experience of platformapplications can be well used for the development of the SouthChina Sea oil and gas field.     

Dynamic interaction of parallel moving ships in close proximity

Nowadays,there are many studies conducted in the field of marine hydrodynamics which focus on two vessels traveling and floating in sufficiently close proximity to experience significant interactions.The hydrodynamic behavior of parallel moving ships in waves is an interesting and important topic of late.A numerical investigation has been carried out for the prediction of wave exciting forces and motion responses of parallel moving ships in regular waves.The numerical solution was based on 3D distribution technique and using the linear wave theory to determine the exciting forces and ship＇s motion.The speed effects have been considered in the Green function for more realistic results.The numerical computations of wave exciting forces and motion responses were carried out for a Mariner and Series 60 for the purpose of discovering different Froude numbers and different separation distances in head sea conditions.Based on the numerical computations,it was revealed that the sway,roll and yaw have a significant effect due to hydrodynamic interaction.     

Research and development of a digital design system for hull structures

Methods used for digital ship design were studied and formed the basis of a proposed frame model suitable for ship construction modeling. Based on 3-D modeling software, a digital design system for hull structures was developed. Basic software systems for modeling, modifying, and assembly simulation were developed. The system has good compatibility, and models created by it can be saved in different 3-D file formats, and 2D engineering drawings can be output directly. The model can be modified dynamically, overcoming the necessity of repeated modifications during hull structural design. Through operations such as model construction, intervention inspection, and collision detection, problems can be identified and modified during the hull structural design stage. Technologies for centralized control of the system, database management, and 3-D digital design are integrated into this digital model in the preliminary design stage of shipbuilding.     

A dual measurement method of strain and temperature

With the rapid development of China's foreign trade, the coastal and inland waterway transport has been increased rapidly. The potential market for marine engines is more and more obvious. The measurement of the engine temperature and strain becomes very important. The fluorescence fiber sensors are broadly used to measure temperature, concentration, and pH value, etc. The fluorescence sensing systems are based on different principles, namely fluorescence intensity, fluorescence intensity ratio, and fluorescence lifetime. The fluorescence lifetime is an effective parameter for sensing purpose, because it is independent of the intensity of the pumping source and does not need expensive narrow-band filters. An experiment system has been established, in which some samples were produced to measure the fluorescence lifetime and temperature characteristics and the relationship of the strain and temperature versus the fluorescence lifetime was achieved at the same time. The experiment result was fitted and analyzed. The test results show that the fluorescence lifetime decreases with the increasing of temperature. The change of fluorescence lifetime with the strain is inconspicuous comparing to that with the temperature.     

Motor Driving Leg Design for Bionic Crab-like Robot

The paper presents the design of walking leg for bionics crab-like robot, which is driven with micro servo motor. The kinematic characteristics of the bionics machine are analysed for optimized structure parameters, which has been used in the robot design. A three closed loop motor control system structure for joint driver is also given, as well as the multi-joint driving system for walking robot leg.     

船舶电站自动控制系统软硬件设计

随着对船舶电站自动化程度要求越来越高，出现了以计算机和PLC控制为核心的船舶电站自动控制系统．本文给出了这种系统的软硬件设计，上位机控制程序用VC＋＋开发，包括了电站配电、并车、保护等全部功能，利用RS485总线实现与下位机PLC的通讯，PLC完成模拟量采集运算和开关量的控制．整个系统既能通过手动控制开关对现场硬件直接操作，也可通过遥控开关切换到计算机软件来控制硬件部分运行工作．     

船舶监控网络中的冗余设计和实现

当前船舶自动化的发展方向是用计算机网络实现船舶机电设备与航海仪器的综合监视、控制和管理，即实现数字化船舶监控。作者结合三年多来在系统设计、软硬件开发和实际工程应用方面的经验，提出了下层使用现场总线、上层使用以大网实现船舶综合网络监控的系统设计方案，给出了其中上层计算机网络的系统组成、软件分布和确保系统高性能运行的一些技术手段，详细论述了系统中所采用的各种软硬件冗余功能和实现原理，给出了部分实现代码。     

海外某集装箱码头冷藏箱管理系统解决方案

全球集装箱码头自动化发展趋势已日渐明显,将冷藏箱纳入码头自动化管理系统的需求必不可少。研究对冷藏箱进行监控、管理的方法,利用CAN总线将终端设备及控制器组网,实现对冷藏箱温度、工作状态及耗电量的7×24 h监控,并结合境外某集装箱码头,给出一种基于CAN总线及光缆组网方式的冷藏箱监控管理系统解决方案,以实现实时监管,降低人工操作成本,提高整个集装箱码头自动化管理效能。     

内河船舶航速预报及能效评估软件开发

随着船舶行业的不断发展和能效指数概念的推行,迫切需要研发一种计算软件来快速评估船舶能效。文中采用修正的艾亚法进行船舶有效功率估算、基于图谱法进行螺旋桨的设计及推进性能计算、进行船舶航速预报及能效评估,并基于C++开发平台,开发了内河船舶航速预报及能效评估软件。结果表明,该软件使用方便、运算快速,具有良好的实用性。     

基于GPS的港口流动机械实时监控系统

采用MapxInfo公司的MapX作为地图组件,将GPS全球卫星定位技术用于车辆定位,GPRS全球移动通信系统用于与监控中心通信,通过在VisualC++软件开发环境下嵌入地理信息系统组件,实现对港口流动机械的实时跟踪、历史记录回放和实时机械调度。     

基于北斗定位系统和MGIS的海军装备保障指挥自动化系统

针对海军装备保障指挥的军事需求,分析北斗导航定位系统和MGIS的功能特点,提出一种基于北斗导航定位系统和MGIS的海军装备保障指挥自动化系统设计方法。该方法将计算机技术、MGIS、北斗卫星定位通信技术有机结合起来,实现装备保障指挥的自动化和数字化。结果表明,该技术可以使定位信息与电子地图实时地、准确地进行配准,使指挥员对战场环境有更全面、深刻的了解,大大加强对装备保障的全面控制和管理,提高装备保障的效能。     

船舶航行性能综合优化研究

船舶航行性能优化是一个非常复杂的问题,它具有多个设计变量,多个约束和多个极点.传统的优化方法通常无法解决该问题.文中采用了一种传统的优化方法一复合形法(CA)和遗传算法(GA),模拟退火算法(SA)来计算船舶航行性能优化问题,比较了三种优化方法的输出结果并选取最好的那个解作为最终的优化结果.通过这种方法.可以以更高的概率获得真实的最优解.应该指出的是,这三种算法都作了某种程度上的改进.作者采用C++语言基于面向对象思想开发了计算软件-ShipPO.文中列出的所有船舶航行性能优化计算结果都是在ShipPO平台上计算出来的,结果表明采用三种优化方法计算一次船舶航行性能优化问题耗时并不太多.最终的结果表明ShipPO具有很强的寻找全局最优解的能力,它能够很好地满足工程需要.     

基于Bowring公式的超视距目标定位算法实现

针对现代海战中超视距目标探测定位问题,提出利用中继平台探测目标,运用Bowring公式解算出目标到攻击舰的距离和方位角,实现超视距定位的算法,并在Visual C++平台上完成工程实现.经过应用和分析,基于Bowring公式的超视距目标定位算法具有较好的工程可实现性.     

基于MapX的海战战术推演软件设计与实现

针对当前战术推演的实际需要,采用面向对象的思想提取作战实体等对象的属性,进行推演软件的系统设计,完成了战术推演软件的结构、功能和数据库设计。运用多线程的技术,直接将MapX组件的GIS功能嵌入到Visual C＋＋集成开发环境编制的应用程序中,实现了推演软件的各项功能。