无接触网有轨电车车地无线传输系统研究

针对无接触网有轨电车设计了一套基于大数据分析技术及物联网技术的车地无线传输系统。介绍了该系统的系统架构、系统功能及设计要点。该系统能够显著提升列车车地数据传输的安全性、高效性及便捷性,提高了无接触网有轨电车车地传输技术和智能化应用水平。同时,该系统具有良好的可扩展性,可满足各类城市轨道交通车辆车载设备调试、维护以及数据传输的应用需求。     

新型局域共振橡胶减振垫振动传递特性测试分析

为了研究一种应用于浮置板轨道结构的新型橡胶减振垫的振动传递特性,对比某基于局域共振新型减振垫与普通橡胶减振垫的减振性能,研究预压质量与激振加速度对振动传递特性的影响,对新型橡胶减振垫进行刚度试验与振动传递特性试验,测试其在30~200 Hz频率下的传递特性,试验过程中采用不同的预压质量与激振加速度,振动传递特性测试采用加速度激振的方法,以加速度传递率作为减振垫振动传递特性的评价指标。结果表明:新型减振垫加速度传递率更小,减振效果更好,最大可以减小10 dB左右;减振垫上方预压质量对振动传递特性有较大影响,预压质量越大,加速度传递率越大,减振效果越差;减振垫的刚度对其振动传递特性有一定的影响,激振的加速度幅值对加速度传递率影响较小。     

On the network connectivity of platoon-based vehicular cyber-physical systems

In the past few years, vehicular ad hoc networking (VANET) has attracted significant attention and many fundamental issues have been investigated, such as network connectivity, medium access control (MAC) mechanism, routing protocol, and quality of service (QoS). Nevertheless, most related work has been based on simplified assumptions on the underlying vehicle traffic dynamics, which has a tight interaction with VANET in practice. In this paper, we try to investigate VANET performance from the vehicular cyber-physical system (VCPS) perspective. Specifically, we consider VANET connectivity of platoon-based VCPSs where all vehicles drive in platoon-based patterns, which facilitate better traffic performance as well as information services. We first propose a novel architecture for platoon-based VCPSs, then we derive the vehicle distribution under platoon-based driving patterns on a highway. Based on the results, we further investigate inter-platoon connectivity in a bi-directional highway scenario and evaluate the expected time of safety message delivery among platoons, taking into account the effects of system parameters, such as traffic flow, velocity, platoon size and transmission range. Extensive simulations are conducted which validate the accuracy of our analysis. This study will be helpful to understand the behavior of VCPSs, and will be helpful to improve vehicle platoon design and deployment.     

A macroscopic loading model for time-varying pedestrian flows in public walking areas

A macroscopic loading model applicable to time-dependent and congested pedestrian flows in public walking areas is proposed. Building on the continuum theory of pedestrian flows and the cell transmission model for car traffic, an isotropic framework is developed that can describe the simultaneous and potentially conflicting propagation of multiple pedestrian groups. The model is formulated at the aggregate level and thus computationally cheap, which is advantageous for studying large-scale problems. A detailed analysis of several basic flow patterns including counter- and cross flows, as well as two generic scenarios involving a corner- and a bottleneck flow is carried out. Various behavioral patterns ranging from disciplined queueing to impatient jostling can be realistically reproduced. Following a systematic model calibration, two case studies involving a Swiss railway station and a Dutch bottleneck flow experiment are presented. A comparison with the social force model and pedestrian tracking data shows a good performance of the proposed model with respect to predictions of travel time and density.     

Implementing first-in–first-out in the cell transmission model for networks

In traffic assignment models with time-varying flows (dynamic network loading or dynamic traffic assignment), overtaking behaviour is normally not included in the model and, in that case, it is important that the model at least approximates first-in–first-out (FIFO), to prevent deviations from FIFO that are arbitrary or unrealistic or not physically possible. For the cell transmission model (CTM) it has recently been shown that the usual recommended method for preserving FIFO will ensure FIFO for each cell taken separately but does not fully ensure FIFO in the transition between cells and hence does not fully ensure FIFO for sequences of cells or for links or for routes. As a result, deviations from FIFO can easily occur and cumulate along the links or routes. In view of that, we define and analyse three different levels of satisfaction or approximation of FIFO, together with corresponding methods for achieving them. Two of these are existing methods and one is new. We develop, analyse and compare the three methods and the extent to which each of them adheres to FIFO for sequences of cells and links or routes. Also, for two of the methods we present a more detailed algorithm for applying them within the CTM. The paper is concerned with how to implement FIFO in the CTM and not with testing for FIFO or measuring deviations from FIFO.     

基于3D打印技术的两轴变速器教具开发

基于3D打印技术的灵活性、方便性等优点,3D打印技术在许多领域得到广泛的应用;因此引来诸多关注,并在自制教具模型方面得到推广。目前汽车变速器空间结构复杂、难以拆卸,所以在教学中存在抽象、枯燥等现象。为了提高"教、学、做"一体化教学效果,利用3D打印技术打印变速器教具模型,满足汽车专业教学需求。同时提高了学生的实践技能、还为教学节约了成本,还提高了课堂的趣味性及效率。     

简述视频监控系统在地铁通信中的集成与施工经验

为了使读者更多了解视频监控系统在地铁中的应用,简要讲述地铁通信中视频监控系统的集成方案选取、互联互通、录像存储、视频传输及相关施工方面的经验。     

变速器齿轮冲击试验的加载方式研究

通过对变速器疲劳寿命台架试验的故障分析，研究其齿轮在不同加载方式下的损坏情况。     

高速公路收费传输网络的防病毒安全策略浅析

计算机病毒是高速公路收费网络数据和应用系统安全的主要隐患之一。随着我省高速公路规模的不断扩大,传统的完全依赖商品化防毒软件的思想,不足以抗拒日益猖獗的计算机病毒。试图在收费网络整体建设思想上,对我省高速公路传输网络上的防病毒安全策略进行一些探讨。     

240／275系列机车柴油机传动机构中间齿轮装配破损故障的技术对策

根据沈阳铁路局近年240／275系列机车柴油机传动机构中间齿轮装配破损的数据统计，分析了故障发生的原因，提出了解决问题的技术措施。