一种基于定位和姿态数据确定试验船质心的方法

针对试验舰质心确定困难问题,提出了一种基于定位和姿态数据的试验舰质心确定方法。通过建立试验舰姿态与传感器中心诱导升沉的关系,推导出了试验舰锚泊状态下质心在船固坐标系中位置的解算模型。实验结果表明,采用本方法进行试验舰质心确定不需添测深仪以外的设备,确定的试验舰质心具有较高的精度,能明显地提高舰载无人飞行器惯导对准效率。     

海洋生态环境监测传感器的应用与发展

受人类活动的影响,海洋污染日益严重。我国海岸带、河口和海湾生态系统均受到了不同程度的破坏。海洋生态环境监测传感器的应用可实现实时海洋环境的监测和快速预警,对于预防海洋灾害、调节海洋经济发展与环境之间的矛盾有重要意义。文中归纳了海洋生态环境类传感器所应用的分析检测技术,总结了目前所研发的各类海洋生态环境传感器,预测了传感器的发展趋势,并对我国未来传感器的研究工作提出了建议。     

单一移动天线RTK监测船只升沉的测试结果及其分析

根据单一移动天线的GPSRTK测试试验,分析了GPSRTK的测试结果。试验表明在一般海况下单一移动天线的GPSRTK是监测测量船实时升沉的又一种有效手段,对提高海上测深精度具有重要意义。     

使用姿态传感器时动吃水改正问题探讨

根据测深中心深度计算公式,提出了动吃水改正直接采用测深换能器动吃水所存在的问题,详细论证了姿态传感器与测深换能器偏心安装时,采用姿态传感器处的动吃水和静态吃水变化推算测深中心吃水的必要性,给出了动态吃水改正的具体建议.     

水声换能器动态吃水与传感器技术探讨

分析了水声换能器静态吃水和动态吃水的差异,以及由这种差异带来的测量精度误差。对压力式验潮仪测量潮汐变化的基本原理和工作模式进行了剖析,探讨了采用压力传感器进行测量水声换能器动态吃水的可能性,并提出了测量水声换能器动态吃水的新概念、新方法。     

海洋监测传感器网络概念与应用探讨

通过介绍国外在军用和民用领域海洋监测传感器网络的应用情况,结合我国海洋监测技术发展的现状,分析了传感器网络在海洋监测中应用的概念和内容,并对应用技术研究问题进行了探讨。     

Experimental Study and System Identification of Hydrodynamic Force Acting on Heave Damping Plate

Although Morison equation is often applied for simulating hydrodynamic force of marine structure, it may give poor results when non-linear behavior is severe or random wave is encountered. This leads to some modifications of Morison equation or other methods for predicting hydrodynamic force. One of them is the system identification technique. In this paper, NARMAX model theory is firstly used to identify the hydrodynamic system of heave damping plates, which are commonly installed on spar platform. Both linear and non-linear models are obtained. The comparisons between the predieted results and measured data indicate that NARMAX model can predict hydrodynamic force of a heave damping plate very well. The measured data for identification originate from forced oscillation tests, which are random records with given spectrum. The forced oscillation forms in experiment also contain simple harmonic, multi-frequency ones.     

Heave compensation system of lifting pipeline for deep-sea mining based on combined action of vibration absorber and accumulator

ABSTRACT

A heave compensation system combined with a vibration absorber and accumulator is proposed, with regard to the requirement for poly-metallic nodule mining systems at an ocean depth of 6,000?m in China. The principle of the compensation system was analyzed, its main parameters were designed, and its mathematical model was established. The system performance was simulated and analyzed in MATLAB, and the frequency domain characteristics and compensation rate of the system with different volume accumulators, and with or without vibration absorbers, were compared. A simulation test of the compensation system was conducted. The proposed compensation system had a better compensation effect for a random wave interference under level-6 sea conditions, and the compensation rate being more than 72% with optimal system parameters.     

海洋环境无线传感器网络监测体系与应用技术研究

针对目前海洋环境监测中急需解决的主要技术问题.对海洋环境无线传感器网络监测的体系结构进行了研究,通过对Crossbow无线传感器网络的拓扑结构和软件架构进行分析与试验.提出其技术优势和有待解决的应 用问题.     

Experimental Investigation of the Resistance Performance and Heave and Pitch Motions of Ice-Going Container Ship Under Pack Ice Conditions

In order to analyze the ice-going ship’s performance under the pack ice conditions, synthetic ice was introduced into a towing tank. A barrier using floating cylinder in the towing tank was designed to carry out the resistance experiment. The test results indicated that the encountering frequency between the ship model and the pack ice shifts towards a high-velocity point as the concentration of the pack ice increases, and this encountering frequency creates an unstable region of the resistance, and the unstable region shifts to the higher speed with the increasing concentration. The results also showed that for the same speed points, the ratio of the pack ice resistance to the open water resistance increases with the increasing concentration, and for the same concentrations, this ratio decreases as the speed increases. Motion characteristics showed that the mean value of the heave motion increases as the speed increases, and the pitch motion tends to increase with the increasing speed. In addition, the total resistance of the full-scale was predicted.     

Distribution of Time-Averaged Suspended Sediment Concentration Due to Waves

According to the mechanism of sediment suspension under waves,namely,the main reason of sediment suspension changes from the turbulent mixing in the bottom boundary layer to the periodic motion of the water particle near the free water surface,a three-hyer model d sediment concentration distribution due to waves is presented along the whole water depth based on the concept of the finite mixing |ength.The determination of the parameters in the model is discussed and an empirical formula is suggested.Comparisons between the calculated results and the measurements indicate that the resuits of the model agree well with the data from both the large and small scale flume experiments.     

大直径浮式结构涡激振动的数值模拟

通过数值模拟的方法研究Spar平台两自由度涡激运动,建立考虑流固耦合时Spar平台涡激运动时域数值模型,采用Matlab软件编程计算了Spar平台在不同流速下的两自由度涡激运动响应,并比较了Spar平台涡激运动时非线性阻尼对于结构的影响。通过对数值模型模拟结果的比较发现,非线性阻尼能降低Spar平台两向涡激运动响应的计算结果,尤其是当平台发生共振时,这个影响更为显著。