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951.
Energy efficient techniques are receiving increasing attention because of rising energy prices and environmental concerns. Railways, along with other transport modes, are facing increasing pressure to provide more intelligent and efficient power management strategies.This paper presents an integrated optimization method for metro operation to minimize whole day substation energy consumption by calculating the most appropriate train trajectory (driving speed profile) and timetable configuration. A train trajectory optimization algorithm and timetable optimization algorithm are developed specifically for the study. The train operation performance is affected by a number of different systems that are closely interlinked. Therefore, an integrated optimization process is introduced to obtain the optimal results accurately and efficiently.The results show that, by using the optimal train trajectory and timetable, the substation energy consumption and load can be significantly reduced, thereby improving the system performance and stability. This also has the effect of reducing substation investment costs for new metros. 相似文献
952.
Cross-border transit facilities constitute major public investment, and thus must serve the long-term needs of the communities, such as providing access to schools and businesses, contributing to a shared regional culture and lifestyle, fostering international trade, and supporting jobs for the region’s residents. Numerous studies have been conducted to evaluate the economic implications of vehicular flow delays at border crossings, however none of the studies focused on assessing cross-border flow of bus passengers and pedestrians. Since pedestrians are considered to be autonomous, intelligent, and perceptive, it is a challenging task to predict pedestrian movement and behavior in comparison to vehicular flows which follow a specific set of traffic rules. This paper presents a multiagent based multimodal simulation model to evaluate the capacity and performance of a cross-border transit facility. The significance of this research is the use of dynamic mode choice functionality in the model, which allows an individual person to make instantaneous choices between available modes of transportation. The scope of interest of the paper is limited to simulating access interface, circulation areas, ancillary and processing facilities. The developed model was calibrated to ensure realistic performance, and validated against specific performance criteria such as throughput per processing facility. In order to demonstrate the applicability of the developed simulation model, capacity and operational planning of a pedestrian transit facility was performed. The relative performance of alternative design or configuration was evaluated using the level of service criteria. Lastly, the effectiveness of each proposed capacity or operational improvement strategy was compared to the “do-nothing” scenario. 相似文献
953.
Arctic sea routes have for long attracted interest from observers and shipping companies because of their shorter distances between the Atlantic and the Pacific. The prevalence of sea ice prevented the real development of a significant traffic, but did not prevent research from trying to assess the economic viability of these routes. With the actual present melting of sea ice in the Arctic, this effort at modeling the profitability of Arctic shipping routes received a new impetus. However, the conclusions of these studies vary widely, depending on the chosen parameters and their value. What can be said of these models, from 1991 until 2013, and to what extent can a model be drawn, capitalizing on twenty years of simulations? 相似文献
954.
955.
汽车车身板料冲压成形分析与模拟 总被引:1,自引:0,他引:1
本文综述了车身板料冲压成形分析与模拟的产生,发展和基本方法,及其对优化冲压工艺过程,降低生产成本和缩短开发周期所起的重要作用,文中着重介绍了板料成形分析与模拟的基本数值方法-逐步更新Lagrange方法(U.L.法)以及关于车身覆盖件的数值例子,并指出了今后研究中值得强调和注意的一些问题。 相似文献
956.
本文分析了汽车车轮制动瞬态动力学,结合精确的15自由度空间刚体动力学模型,定量地分析了车轮抱死松开所获得的加减速度值,并为防抱制动提供了准确的加减速度阈值,同时考虑到防抱制动系统本身装置的特性,提出了最佳又符合实际的制动矩控制参数,使用仿真结果更接近实际,为电子防抱制动系统的研究提供较完整的理论体系和分析方法,并开发了汽车电子防抱制动系统模型(HVOSM-ABS)及模拟程序,该程序具有16种不同的 相似文献
957.
本文描述了17自由度汽车全工况操纵与制动过程动力学模型的建模,仿真与验证。该模型考虑了侧风,有无防抱系统,高速,变车速,双移线转变制动等各种极端工况,仿真结果与美国密执安大学的仿真结果十分吻合,证实了该算法与模型具有很好的精度。 相似文献
958.
介绍了柴油机气缸盖进气道芯盒模具的传统制造工艺,针对其人为因素影响较多,模具制造精度低,周期长和使用寿命短等问题,采用了CAD/CAM技术,从而缩短了模具制造周期,提高了产品质量,重点阐述了采用CAD/CAM技术制造该模具的工艺流程和需解决的关键性技术问题。 相似文献
959.
汽车安全气囊展开过程计算机仿真及其接触搜寻方法 总被引:3,自引:0,他引:3
本文系统地讨论了安全气囊展开过程计算机仿真中接触界的搜寻方法。该方法以级域理论的基本思想为基础,分接触前搜寻和接触后搜寻两大部分,具有速度快,可靠性好,通用性强等优点,并被移植到LS-DYNA3D中进行了初步验证。 相似文献
960.