排序方式: 共有47条查询结果,搜索用时 46 毫秒
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电动汽车用NiMH电池建模及基于状态空间的SOC预测方法 总被引:1,自引:0,他引:1
电动汽车的电池管理系统需要精确、可靠的电池荷电状态(SOC)预测器。针对氢镍(NiMH)电池,提出了一种集总参数等效电路模型,介绍了通过实验获得电池参数的方法。该模型考虑了温度对电池参数的影响,能反映电池充放电的动态过程。文中用状态空间描述了R—C电池模型,在此基础上建立了一种新的基于状态空间的SOC递推算法,并对电池的充放电过程进行了仿真计算。分析表明,提出的SOC估计方法同样可用于其它类型的动力电池。 相似文献
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OD矩阵是交通规划、管理与控制的重要决策支持数据,OD矩阵估计是获得OD矩阵数据的一种先进技术方法。主要对道路交通系统的OD矩阵估计(静态和动态)方面的相关主要文献进行概括总结与简单评述,包括研究现状及存在的主要问题等。主要涉及道路观测点的优化布设、静态OD矩阵估计模型及算法、动态OD矩阵估计模型和方法等几方面。最后,总结了近期OD矩阵估计方面的主要研究热点。 相似文献
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The Macroscopic Fundamental Diagram (MFD) has been recognized as a powerful framework to develop network-wide control strategies. Recently, the concept has been extended to the three-dimensional MFD, used to investigate traffic dynamics of multi-modal urban cities, where different transport modes compete for, and share the limited road infrastructure. In most cases, the macroscopic traffic variables are estimated using either loop detector data (LDD) or floating car data (FCD). Taking into account that none of these data sources might be available, in this study we propose novel estimation methods for the space-mean speed of cars based on: (i) the automatic vehicle location (AVL) data of public transport where no FCD is available; and (ii) the fused FCD and AVL data sources where both are available, but FCD is not complete. Both methods account for the network configuration layout and the configuration of the public transport system. The first method allows one to derive either uni-modal or bi-modal macroscopic fundamental relationships, even in the extreme cases where no LDD nor FCD exist. The second method does not require a priori knowledge about FCD penetration rates and can significantly improve the estimation accuracy of the macroscopic fundamental relationships. Using empirical data from the city of Zurich, we demonstrate the applicability and validate the accuracy of the proposed methods in real-life traffic scenarios, providing a cross-comparison with the existing estimation methods. Such empirical comparison is, to the best of our knowledge, the first of its kind. The findings show that the proposed AVL-based estimation method can provide a good approximation of the average speed of cars at the network level. On the other hand, by fusing the FCD and AVL data, especially in case of sparse FCD, it is possible to obtain a more representative outcome regarding the performance of multi-modal traffic. 相似文献
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U. Hjorth 《Transportation Research Part B: Methodological》1999,33(8):345
From basic assumptions about independent and consistent driver behaviour, and with data from traffic counts, we derive statistical properties of regression or correlation estimates of route selection probabilities, turning probabilities and travelling times. Our modelling is conditional in a way that avoids most traffic generation problems and permits an asymptotic analysis of the precision under mild assumptions allowing non-stationarity. This allows us to put together non-stationary data from the corresponding time intervals during several days when we aim at high precision estimates. 相似文献
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介绍了一种方法,可以对结构使用寿命进行概率评估及选择最佳养护计划。这种方法基于一种新的方法,以评估侵蚀环境扩散侵蚀下混凝土结构的时变性能。概率分析的结果可以用来帮助选择不同养护类型下的修复方案,以使结构使用寿命达到设计值。在一个空心墩上的应用显示了本方法的效果。 相似文献
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目前在公路建设项目前期工作中,经济评价结论决定了项目的可行性。随着高速公路建设步伐的加快,由于项目造价高而交通量预测值低且车辆收费标准增长缓慢,经济评价特别是财务评价效果越来越差,部分项目经济评价无法通过。综合评价是在经济评价的基础上。综合项目在经济、政治、国防、社会效益等多领域因素的分析,得到项目的综合评价结论,为项目的可行性提供依据。 相似文献
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锚泊中船舶卧底链长的一种估算方法 总被引:1,自引:0,他引:1
为了从定量上掌握锚泊船卧底锚链的长度 ,保证锚泊安全 ,本文根据锚链悬链线特殊性质 ,提出了在出链长度一定的情况下估算卧底链长的一种简易方法 ,即根据锚链在锚链筒外孔处与铅垂线的夹角来估算卧底链长的方法 ,并对估算误差作了简要分析。分析表明 ,当锚链张角 <5 0°时 ,误差较小 ;当锚链张角 >6 0°时 ,误差偏大 ,但仍可满足航海实践需要 相似文献