Monitoring of suction bucket jackets for offshore wind turbines: Dynamic load bearing behaviour and modelling

Suction bucket foundations for offshore wind turbines (OWT) have considerable advantages compared to conventional foundation types: Due to the installation process with dead weight and applied negative pressure, noise from pile driving can be completely avoided. In addition, the installation process of the whole substructure, consisting of the buckets connected to the jacket, can be carried out in one work step, which increases efficiency. A prototype of the suction bucket jacket was installed in the wind park ‘Borkum Riffgrund 1’ (North Sea) in August 2014. Due to the pre-installed and comprehensive measuring system, it was possible to monitor all installation and operating phases. The data analysis of a storm event show an amplitude and frequency-dependent behaviour of the soil stiffness and the suction bucket foundation without wind turbine. In the frequency range of the first and second eigenfrequency (0.2 Hz < f < 5 Hz), the system behaves linearly. Here, the Frequency Domain Decomposition is used for identification and monitoring. For the lower frequency band (0.05 Hz < f < 0.2 Hz) where higher forces and displacements occur, a non-linear multilayer perceptron is chosen to model the non-linear relations between measurements. By applying two mathematical models for the relevant frequency ranges, all the information from the measurement data can be used for system identification and novelty detection under varying environmental conditions.     

Rollover prevention for heavy trucks using frequency shaped sliding mode control

Control and handling of heavy commercial vehicles carrying liquid cargo are influenced by liquid movement within the partially filled tank. During steering and braking maneuvering tasks, the truck may exhibit unstable behavior at lateral acceleration levels of 0.3 g to 0.4 g [m/s²]. The fluid slosh forces and dynamic load transfers in the lateral and longitudinal directions and parametric uncertainties caused by moving liquid cargo affect the overall dynamics of the vehicle. To solve a physical problem about the minimal excitation of the slosh dynamics associated with the longitudinal and lateral excitation of the vehicle, dynamic sliding surface design combined with recursive backstepping algorithm is introduced. Compensator dynamics are introduced in the sliding mode through a class of switching surfaces which has the interpretation of linear operators such that the resulting closed-loop system retains the insensitivity to uncertainties in the sliding mode while minimizing the excitation of flexible modes and unmodeled dynamics. The frequency shaped backstepping sliding mode algorithm, proposed by Acarman and Özgüner [Frequency shaping compensation for backstepping sliding mode control. Paper presented at the 15th IFAC World Congress, Barcelona, Spain, 2002], is designed to stabilize and to attenuate the sloshing effects of moving cargo by properly choosing the crossover frequencies of the dynamic compensators in accordance with the fundamental frequencies of the slosh dynamics.     

基于先验信息的自适应核函数设计

针对多分量线性调频信号，提出一种新的自适应核函数，并给出了有效的核参数估计方法。相对于自适应高斯核函数而言，该核函数既能获得更好的交叉项抑制效果，又避免了较大的信号能量损失，因而是一种更好的核函数。计算机仿真结果验证了其有效性。     

电控自动变速系统原理分析及应用

以林德正面吊变速系统为例,介绍和分析电控自动变速系统的电路组成及工作原理,并针对实际工作中遇到的典型故障,举例说明检测修理方法.     

20.5万吨散货船轴带发电机系统设计研究

为降低大型商业运输船舶无限航区航行时能源消耗,在20.5万吨级大型散货船上采用PWM型轴带发电机,以降低运输成本,提高环保性能,提高经济效益。     

浮式抗冰平台设计理念及水动力特性研究

钻探极地地区近海石油和天然气资源对移动式离岸钻井平台的水动力性能、抗冰性能和作业性能有着极大的要求。本文主要介绍了浮式抗冰平台的设计方案,并结合当今最新一款半潜式抗冰平台的设计理念,分别从频域和时域分析的角度与传统的半潜式平台作对比,分析得出其具有优越的水动力性能,垂荡、横摇、纵摇运动响应都优于传统的半潜平台,为下一步抗冰性能分析及其关键技术的研究做基础,同时也给半潜式平台带来新的设计理念,为浮式抗冰平台的设计建造提供合理思路。     

ZPW-2000A型无绝缘移频轨道电路室内设备故障处理

通过对ZPW-2000A无绝缘移频自动闭塞室内设备的探究,结合现场实际情况,用示意图的形式直观地表达出室内设备的工作条件及发生故障时的现象,通过现象快速定位故障原因,对于安全行车、压缩延时有着重要意义.     

Case study on health assessments related to a modal shift in transportation

Historically, the emphasis on environmental problems has been on visible pollution. However, as a result of the reduction in visible pollution in recent years, many people have become anxious about invisible dangers. The method for objectively evaluating these invisible dangers is risk assessment. Therefore, in the present study we propose and discuss a method for evaluating the influence of a modal shift in transportation on cancer risk using the technique of risk assessment. First, two representative transportation routes were selected for analysis. Subsequently, the level of airborne carcinogens from the exhaust of ships and trucks was determined. Next, the concentration of each carcinogen in locations across Japan was calculated. Finally, the number of people in Japan who will suffer from cancer related to these emissions was derived and the effects of the modal shift on health are discussed.     

ZPW-2000A移频监测系统的解决方案

在ZPW-2000A移频监测系统设计中，构成分布式采集方式，解决了设备安装的问题，采用通信前置机＋现场总线＋100Mb／s以太网，提高了系统的采集速率，增加了系统构成的灵活性。专门设计的采集盒，提高了信号采集的准确性和实时性，有利于进行专业化的开发和生产。