基于列车实时数据协议的以太网高速通信技术

为了满足列车通信网络中过程数据与消息数据传输的需要,在可扩展处理平台上,设计了一种基于列车实时数据协议(TRDP)的以太网网卡,并在此基础上提出一种片间总线接口方法,实现了对过程数据和消息数据的实时交互,解决了传统片间总线速率低的问题;同时利用串并联端接电阻,从硬件上改善了高速片间总线的信号完整性,保证了高速模式下过程数据与消息数据的实时交互;在所搭建的研究测试平台上,实现了TRDP对过程数据的高速传输。     

基于Prescan 的信号灯路口跟停场景虚拟重构

为满足我国智能驾驶汽车测试场景库的搭建和ADAS(高级驾驶辅助系统)功能研发和验证的需求,设计了一种基于Prescan的交通信号灯路口车辆跟停场景虚拟重构方法,该方法由道路环境建设模块、初始条件设定模块和车辆控制模块组成。道路环境建设模块通过输入道路参数信息构建虚拟道路,初始条件设定模块通过输入本车和目标车的初始位置、初始速度信息确定零时刻车辆和道路的空间位置及状态信息,车辆控制模块依据车辆速度位置等信息,利用训练的神经网络控制本车加速度,实现跟停场景的虚拟重构。仿真结果表明,该方法可以实现交通信号灯路口车辆跟停场景的虚拟重构。     

不同航态下船舶运动规律仿真研究

主要根据波浪叠加理论,采用ITTC单参数标准海浪谱对随机海浪作用下船舶线性横摇、纵摇运动进行建模和仿真研究,探讨不同船型、各种航态(不同海况、不同航速、不同航向)下船舶横摇和纵摇运动规律,为进一步研究船舶的减摇预报与控制打下基础。     

船舶火灾模拟训练系统研究

船舶火灾模拟训练系统可以仿真船舶火灾的三维环境,对船员和消防人员进行模拟训练．在已研制船舶操纵模拟器的基础上对船舶火灾模拟训练系统各模块的组成及作用进行探讨,分析船舶火灾蔓延模型、船舶火灾仿真等关键技术．在优化大涡模拟技术和合理处理场、区、网模型间的边界耦合问题的基础上,提出了场区网模型模拟船舶火灾蔓延的过程．提出了采用物理模型方法,结合纹理技术和粒子系统方法模拟船舶火灾场景．     

城市轨道交通综合监控系统的实时性设计

综合监控系统的实时性指标是评价系统性能优劣的重要指标,其性能直接影响地铁运营调度的质量.通过对城市轨道交通综合监控系统核心平台及其集成子系统网络结构的分析,构建了一个度量系统实时性的分析计算模型.以该模型为基础,分析研究网络拓扑结构、数据通信机制等因素对系统实时性的影响,并提出了优化系统实时性设计的措施:尽量减少网络层级,推荐集成子系统与综合监控系统核心平台一体化设计;均衡分配每个数据传递路径中低速数据通信设备的数量;根据各层级网络实时数据的容量和网络传输能力,合理确定各层级网络的数据通信机制,底层网络可采用轮询方式,上层网络可采用变化数据主动上传方式;合理提高网络设备的性能,避免通信瓶颈.     

The value of real-time traffic information in urban freight distribution

Routes optimization in urban freight distribution is usually an off-line process based on the knowledge of historical conditions on the network. Real-time data provided by Intelligent Transportation Systems (ITSs) enable online re-optimization on the basis of actual traffic conditions.

?This paper evaluates the added value generated by re-optimizing the off-line solution with real-time information. The study is carried out for a practical application to the freight distribution of perishable goods in the city of Rome (Italy). The off-line problem is formulated as a vehicle routing problem with soft time windows while in the online problem it is also allowed to skip some customers or to re-sequence the deliveries. Both versions are solved with different algorithms and with different data sets. Results can be used to evaluate the potential return on investment on the acquisition of different kinds of traffic data. At the same time, results can be of interest for information providers, to fix the price of off-line and online information and/or to estimate the associated potential market share.     

A real-time impact detection and diagnosis system of catenary using measured strains by fibre Bragg grating sensors

This paper describes an impact detection system using strain signals based on fibre optic sensors(FBG) for the real-time monitoring of the catenary system. The proposed detection system consists of three subsystems: a measuring system, a data processing and analysis system, and a status display and data access system. Because the strain signals obey the normal distribution, to monitor the catenary system in real time, a novel method that combines mobile standard deviation with the mobile Pauta criterion is proposed to distinguish real impact from the strain signal background. The use of this adaptive judging method reduces the misjudgment rate of impacts and improves the impact recognition accuracy. These impacts can be identified by the data analysis system, which provides impact location and their causes using the features of the catenary system. This method can simplify the detection system compared with the traditional location method. An application to a commercial metro line system indicated that the impacts on the catenary system were main caused by overlaps, expansion joints or steady arms, and were verified by correspondence with the floor plan of the catenary and manual inspection results. These results verified the reliability and effectiveness of the proposed impact detection system.     

影视摄影中的“三景”辩证关系

景物、景别、景深是影视摄影中三个非常重要的术语，合称“三景”。“三景”在理论表述中，既有各自不同的特质，又有相互之间的关联；在实际应用中，既有技术操作的参与，又有艺术创作的渗入。理清“三景”之间的辩证关系，将为进一步提高影视摄影的技艺水平开启一个新的思路。     

基于ISaGRAF的船舶空压机实时监控系统

空气压缩机作为气动控制系统的气源设备,其在运行过程中的稳定程度和可靠性直接影响到船舶的安全,因此必须对空压机的运行进行全面的监控。文章通过分析ISaGRAF控制软件的体系结构和运行机制,提出了船舶空压机实时监控系统的软PLC实现方法,介绍了该系统的结构、主要功能特点及软件设计等。