高速铁路ZPW-2000A轨道电路故障分析及监测优化

针对客专ZPW-2000A轨道电路故障处理时,仅靠监测手段不能准确区分室内外故障,需要人工测量,处理时间普遍较长的问题,通过分析信号集中监测系统及轨道电路原理,提出在既有监测系统基础上,增设接收电缆模拟网络监测点的优化措施;同时对轨道电路故障进行模拟试验,分析发生故障时各监测点的数据,总结不同种类故障发生时的规律;最后以2个实际案例验证了优化措施的效果。     

Optimal combinations of selected tactics for public-transport transfer synchronization

Handling efficiently and effectively real-time vehicle control is of major concern of public transport (PT) operators. One related problem is on how to reduce the uncertainty of simultaneous arrivals of two or more vehicles at a transfer point. Improper or lack of certain control actions leads to have missed transfers, one of the undesirable features of the PT service. Missed transfers result in increase of passenger waiting and travel times, and of passenger frustration. This work focuses on reducing the uncertainty of missed transfers by the use of control tactics in real-time operation. The developed model improves the PT service performance by optimally increasing the number of direct transfers and reducing the total passenger travel time. This model consists of two policies built upon a combination of two tactics: holding and skip-stop/segment, where a segment is a group of stops. The implementation of the concept is performed in two steps: optimization and simulation. The optimization searches for the best combination of operational tactics. The simulation serves as a validation of the optimal results under a stochastic framework. A case in Auckland, New Zealand is used. The results show that by applying the holding-skip stop, and holding-skip segment tactics the number of direct transfers are increased by about 100% and 150%, and the total passenger travel time is reduced by 2.14% and 4.1%, respectively, compared with the no-tactic scenario. The holding-skip segment tactic results with 47% more direct transfers than the holding-skip stop tactic for short headway operation.     

Eco-driving: An economic or ecologic driving style?

In this work the trade-off between economic, therefore fuel saving, and ecologic, pollutant emission reducing, driving is discussed. The term eco-driving is often used to refer to a vehicle operation that minimizes energy consumption. However, for eco-driving to be environmentally friendly not only fuel consumption but also pollutant emissions should be considered. In contrast to previous studies, this paper will discuss the advantages of eco-driving with respect to improvements in fuel consumption as well as pollutant gas emissions. Simulating a conventional passenger vehicle and applying numerical trajectory optimization methods best vehicle operation for a given trip is identified. With hardware-in-the-loop testing on an engine test bench the fuel and emissions are measured. An approach to integrate pollutant emission and dynamically choose the ecologically optimal gear is proposed.     

Locating charging infrastructure for electric buses in Stockholm

Charging infrastructure requirements are being largely debated in the context of urban energy planning for transport electrification. As electric vehicles are gaining momentum, the issue of locating and securing the availability, efficiency and effectiveness of charging infrastructure becomes a complex question that needs to be addressed. This paper presents the structure and application of a model developed for optimizing the distribution of charging infrastructure for electric buses in the urban context, and tests the model for the bus network of Stockholm. The major public bus transport hubs connecting to the train and subway system show the highest concentration of locations chosen by the model for charging station installation. The costs estimated are within an expected range when comparing to the annual bus public transport costs in Stockholm. The model could be adapted for various urban contexts to promptly assist in the transition to fossil-free bus transport. The total costs for the operation of a partially electrified bus system in both optimization cases considered (cost and energy) differ only marginally from the costs for a 100% biodiesel system. This indicates that lower fuel costs for electric buses can balance the high investment costs incurred in building charging infrastructure, while achieving a reduction of up to 51% in emissions and up to 34% in energy use in the bus fleet.     

铁路调度通信系统的运用与优化

调度通信系统是铁路行车调度指挥的重要组成部分,论述了铁路专用调度通信设备的技术发展历程,针对高铁客专、干线、支线等不同线路主要运用模式和技术特点,提出调度通信系统适应性的发展趋势及技术实现方案。     

铁路路堑挡雪墙设计参数优化数值模拟

风吹雪往往在铁路路堑地段形成较厚的积雪,掩埋线路,影响行车速度,危及行车安全,研究其具有重要的现实意义。基于FLUENT软件,模拟研究不同挡雪墙高度、不同风速下,挡雪墙背风侧风雪两相流的运动特性及挡雪墙参数优化设计。研究表明,风雪流初始速度一定时,挡雪墙背风侧积雪宽度随挡雪墙高度增大而变大,沉积在床面上的雪粒更多,阻雪效果越好;挡雪墙高度一定时,背风侧积雪宽度随风雪流速度的增加逐渐增大,挡雪墙距线路的距离也应越大。在综合考虑工程造价和挡雪效果的基础上,挡雪墙设计时,高度宜在2.5~3.5m,高度越高,风速越大,挡雪墙距线路的距离应越大,一般在20~35m即可。     

基于OIPSO算法的环境最优动力定位控制器设计

环境最优动力定位控制是一种以能量消耗最少为目标的动力定位控制方法,在不需要任何环境传感器的情况下,使其保持在设定区域且消耗能量最少,节约燃料、减少有害气体的排放。首先,提出一种带有目标性初始化粒子群的改进粒子群优化算法(OIPSO),通过引入混沌算子,利用信息熵进行评估对初始化粒子种群进行调整以提高粒子群算法全局搜索能力和收敛速度,具有大范围全局寻优能力。其次,研究设计环境最优艏向控制器控制律,该控制律能满足欠驱动船舶动力定位的控制需求。最后以Cyber Ship Ⅱ动力定位模型船为对象进行仿真验证。结果表明,所提出的寻优算法和改进控制律达到了设计的目的。     

某型矿用胶轮车动力源匹配的研究

随着矿山机械技术的不断提高,在矿山巷道的底板上,液压机械传动防爆无轨胶轮车被大量用来进行运输工作。然而,运输和自卸之间动力源的匹配应加以改善。本文中,在特定类型的防爆胶轮车的基础上,从上述问题出发,通过优化匹配变速箱和匹配动力源,有效提高了防爆无轨胶轮车的动力性能,验证了采用在折中匹配的基础上使用液力机械分流变矩器,以及修正变速箱换挡规律来提升柴油防爆胶轮车的动力性能的方案是合理有效的。     

基于运动学特性的双横臂悬架硬点位置优化

利用空间机构运动学和数值计算的方法对双横臂独立悬架系统进行了运动学分析,以悬架运动学特性设计曲线为优化目标,对悬架硬点的布置位置进行了优化。结果表明,按照优化后的硬点位置计算出的悬架运动学特性曲线与设计曲线基本一致,因此利用该方法可以快速实现对悬架硬点结构的优化布置,提高车辆性能。     

基于时间序列ACO-BP神经网络在基坑变形预测中的应用研究

BP神经网络技术因其良好的非线性动力学特性、函数逼近能力、自组织和自适应能力,已广泛应用于基坑变形预测中。但实际应用过程中发现BP神经网络具有收敛速度慢、初始权阈值对计算结果影响较大,且易陷入局部最优等缺陷。采用引入具有启发式寻优、全局优化特点的蚁群算法优化BP神经网络,对基坑变形进行预测,并与BP神经网络进行比较。结果表明:ACO-BP神经网络模型预测基坑变形可行;预测精度高于BP模型,且结果稳定、速度较快、误差满足工程的要求。