重载铁路移动闭塞系统架构研究

依托大秦铁路,研究重载铁路移动闭塞系统架构.根据移动闭塞原理,设计重载铁路移动闭塞系统架构.详细介绍系统架构设计要点、重载铁路既有信号系统实现移动闭塞功能需新增的关键技术和设备,以及基于列车位置追踪的移动闭塞安全功能.在重载铁路既有线引入移动闭塞系统,可以提升大秦铁路乃至我国重载铁路货物运输能力.     

ATS仿真平台中列车追踪设计与实现

列车追踪是列车自动监控系统的重要功能.首先分析了列车追踪原理.根据ATS仿真平台中站场图实例,重点介绍列车追踪设计与实现过程中需要的线路设备数据和车次号追踪的实现方法.最后通过Visual C++6.0平台根据实际线路数据仿真验证.     

Accommodating user preferences in ad hoc shared ride trip planning using GIS

Ad hoc shared ride trip planning (SRTP) utilizes mobile devices, geo-sensors and wireless networks to match on-the-fly individual travel demand with transport supply. It represents one of many alternatives to single occupancy vehicle use. This paper outlines a SRTP approach via a two-phase algorithm based on user preferences in a time-dependent routing. Whereas current algorithms use minimization of travel time as the only optimization criterion in trip planning, in the framework presented here, the user can specify multiple trip preferences including travel time, walking time, number of transfers between cars and trip length. Various scenarios are simulated in the city of Tehran (Iran) to demonstrate how preference settings affect the routes of ad hoc shared journeys.     

基于路径规划数据的公共交通站点覆盖水平评价方法

为科学合理地评价城市公共交通站点覆盖水平,提高评价方法的准确性和有效性,在分析我国城市公共交通站点覆盖现状和存在问题的基础上,结合基于互联网开放地图平台的路径规划数据,采用以步行实际可达性为主要依据的评价方法对公共交通站点覆盖水平进行研究分析。结果表明：此方法不但适用于区域公交站点布局评价,还可以聚焦于某一条具体的公交线路、自行车停靠点、P+R（Park and Ride）设施、交通枢纽等交通设施,以及快递服务点、公共厕所等生活服务设施的可达性分析和布局优化。最后,从向内深挖自身潜力、向外争取良好环境两个层面,提出了提升我国城市公共交通覆盖水平的措施建议。     

基于运动学和动力学模型的无人驾驶路径跟踪控制器设计

设计了一种应用于无人驾驶控制的基于车辆运动学和动力学模型的路径跟踪控制器,包括运动学和动力学模型、路径跟踪控制模型、地图匹配模型和执行命令融合模型,使用实时车辆姿态信息进行转向角度预测,使用实时车辆定位信息进行反馈控制以消除系统干扰和模型误差。系统硬件包括车辆平台、嵌入式Mbed开发平台、Ubuntu系统运行平台和惯性导航系统,软件框架使用robotic operation system(ROS),使用rosserial服务连接嵌入式Mbed开发板与ROS。实车测试表明控制器系统达到设计目的。     

基于模型预测控制无人驾驶车辆避障轨迹跟踪器设计

针对无人驾驶车辆的轨迹跟踪和避障问题,基于模型预测控制算法设计了避障轨迹跟踪控制器,实现避障和轨迹跟踪功能。在不同车速下采用Matlab和CarSim进行联合仿真试验,结果表明:设计的控制器控制性能和稳定性良好,能满足无人驾驶车辆的避障和轨迹跟踪需求。     

自动化码头多AGV路径冲突的优化控制研究

针对自动引导车(AGV)在自动化码头水平运输过程中可能发生的路径冲突问题,提出一种将AGV路径容量、安全距离、行驶时间及行驶速度相结合的多参数优化控制模型.Dijkstra算法规划多条AGV路径,位向量交集运算法检测路径冲突,改进的速度控制策略通过控制AGV在冲突节点处的行驶速度,解决冲突问题.对某自动化码头的AGV路网进行仿真实验和分析.比较停车策略、速度控制策略和改进的速度控制策略的结果,验证了改进速度控制策略在AGV路径冲突问题中的可行性及有效性.     

线性计划方法及其应用研究

CPM作为十分有用的计划技术在建筑业得到了广泛的使用,但也存在一些不足．而线性计划方法作为一种新的计划技术,针对诸如高速公路、铁路工程等线状工程项目的特点,是编制其进度计划十分有效的工具,但目前在理论和应用研究方面还存在许多不足．因而,文章介绍了线性计划方法并对该方法提出了一些改进．同时,通过案例介绍了线性进度计划的绘制方法和步骤．     

观测路径出行时间下随机网络交通需求估计

道路网络起讫点(OD)需求是城市决策长期交通规划和短期交通管理中的基础参数,准确的交通需求更是实施交通拥堵控制、限行限速、路径诱导等措施的先决条件.综合运用观测的轨迹已知和未知路径出行时间,建立随机网络交通需求估计双层规划模型.上层广义最小二乘模型最小化历史交通需求与待估交通需求、观测路径出行时间与待估路径出行时间之间...     

Monitoring wildlife crossing structures along highways in Changbai Mountain,China

In China, the construction and monitoring of wildlife crossing structures is uncommon. Mountainous area occupies two-thirds area of China. A lot of tunnels (similar to overpasses in developed countries), bridges, and culverts (similar to underpasses) are constructed along highways. In general, these structures are multifunctional, including wildlife migration. However, studies on monitoring these potential crossing structures are almost vacant. Taking two highways in Changbai Mountain area as case studies, infra-red camera trapping and snow tracking were used to investigate the efficiency of tunnels, bridges and culverts on the highways. A total of 13 medium and large-sized wildlife species crossed highway through tunnels, bridges and culverts. One third of species were Chinese national protective species, and almost all species were present within 500 m from Ring Changbai Mountain Scenic highway used bridges and culverts to cross this highway. The tunnel along the expressway (length = 1000 m) and the bridges along the highway (width > 8 m) have been important passages for ungulates, Eurasian red squirrels (Sciurus vulgaris), yellow throated martens (Martes flavigula) and sables (Martes zibellina). Different species preferred to different types of structures, although most species preferred to bridges and tunnels. We suggest that short fences should be set around the bridges and culverts to guide animals to cross the passages, especially for ungulates. Monitoring programs of uses of crossing structures by wildlife should be conducted for at least 2 months to catch most species activity.