中国沿海2018年度船舶黑碳排放分析

对年度船舶黑碳排放进行概述。以2018年度中国沿海为目标区域，对年度船舶活动特征进行分析。基于自动识别系统（Automatic Identification System，AIS）数据，对年度船舶黑碳排放量进行计算，根据计算结果对年度船舶黑碳排放特征进行分析，并提出中国沿海船舶黑碳减排建议。     

Dynamic ice loads for offshore wind support structure design

For offshore wind farms which are planned in sub-arctic regions like the Baltic Sea and Bohai Bay, support structure design has to account for load effects from dynamic ice-structure interaction. There is relatively high uncertainty related to dynamic ice loads as little to no load- and response data of offshore wind turbines exposed to drifting ice exists. In the present study the potential for the development of ice-induced vibrations for an offshore wind turbine on monopile foundation is experimentally investigated. The experiments aimed to reproduce at scale the interaction of an idling and operational 14 MW turbine with ice representative of 50-year return period Southern Baltic Sea conditions. A real-time hybrid test setup was used to allow the incorporation of the specific modal properties of an offshore wind turbine at the ice action point, as well as virtual wind loading. The experiments showed that all known regimes of ice-induced vibrations develop depending on the magnitude of the ice drift speed. At low speed this is intermittent crushing and at intermediate speeds is ‘frequency lock-in’ in the second global bending mode of the turbine. For high ice speeds continuous brittle crushing was found. A new finding is the development of an interaction regime with a strongly amplified non-harmonic first-mode response of the structure, combined with higher modes after moments of global ice failure. The regime develops between speeds where intermittent crushing and frequency lock-in in the second global bending mode develop. The development of this regime can be related to the specific modal properties of the wind turbine, for which the second and third global bending mode can be easily excited at the ice action point. Preliminary numerical simulations with a phenomenological ice model coupled to a full wind turbine model show that intermittent crushing and the new regime result in the largest bending moments for a large part of the support structure. Frequency lock-in and continuous brittle crushing result in significantly smaller bending moments throughout the structure.     

轮毂电机驱动车辆驱动力控制研究

轮毂电机驱动车辆各轮转矩精确可控且响应迅速的特点适用于越野工况，但越野路面起伏不一且附着条件多变，因此，开发基于越野工况辨识的车辆驱动力控制策略，对提升轮毂电机驱动车辆的纵向行驶稳定性具有重要意义。基于动力学模型分析路面附着与路面几何特征，确定可用于越野工况辨识的车辆特征参数集；针对车轮悬空垂向载荷估计失真现象，且由于地面垂向力的实际变化导致车辆垂向载荷分配比例的改变，修正了垂向载荷的计算；利用各特征参数的差异与越野工况的映射关系判定工况属性，采用模糊识别法界定4种地形工况；驱动力控制上层考虑工况与驾驶员影响因素，通过越野工况辨识结果决策驱动利用系数，作为前馈期望转矩调节权重；中层通过四轮垂向载荷得到转矩分配系数，设计驱动力分配算法；下层针对车辆在越野工况下出现车轮滑转与悬空状态，对车轮进行动态转矩补偿。仿真测试与实车验证表明，越野工况辨识结果与预期相符，驱动力控制策略综合优化了车辆稳定性和动力性。