基于社会力的信号交叉口施工区交通流建模

由于施工区的存在,城市道路信号交叉口通行能力下降,车流运行混乱.本文为 了从微观层面研究信号交叉口施工区交通流运行特性,以初始社会力模型为基础,首次提 出一种新的适用于交叉口交通流的社会力模型;通过对影响岛式施工区通行能力的因素 进行分析,设计出一套数据采集方案;利用实测数据并结合遗传算法对提出的模型进行标 定,使用统计学指标对标定结果展开评价.结果表明,提出的新模型仿真得到的交通量与 实测值平均绝对相对误差仅为0.028,能为信号交叉口施工区交通流模拟提供参考.     

基于信号交叉口车头时距分布的VISSIM仿真参数校核研究

为了提高微观交通仿真评价分析的精度和可信度,需要根据实际交通情况对微观交通模型 关键参数进行校核。校核分析了VISSIM 微观交通仿真模型中关键驾驶行为参数和车辆动力性能 等参数,选取信号交叉口车头时距作为仿真校核目标参数,提出了信号交叉口仿真参数校核流 程。通过实际调查重庆市多个信号交叉口,统计得到车头时距分布关系,对仿真校核流程进行了 实例验证。实例验证结果表明,经过参数校核后构建的仿真场景与实际交通运行状态相吻合,以 此进行仿真评价分析具有较高的可信度。     

基于UDS协议的并线辅助系统动态校准

并线辅助作为汽车智能安全技术的重要组成部分,越来越被重视,它通过车载毫米波雷达检测车辆后方目标的运动情况,提醒驾驶者安全范围内有无障碍物或来车,从而消除视线盲区,提高驾驶员的行车安全。由于车辆自身及雷达支架结构的误差,新安装后的雷达需要进行校准,而UDS诊断协议作为产线设备及售后诊断设备的基础通信协议,将为并线辅助系统动态校准提供网络通信支持。     

传统方法在水下相机标定应用中的研究

针对加装保护壳体的水下相机光路较空气中复杂,传统成像模型及标定在水下是否满足工程要求的问题,在带畸变的小孔成像模型中利用传统方法进行了大气和水下的相机标定,验证了两种情况下标定偏差的存在;利用神经网络方法对水下相机标定进行了对比实验,结果显示传统方法在工程应用中的水下相机标定中仍具有优势。     

三缸发动机分解摩擦功试验研究

论文主要研究三缸发动机分解摩擦功试验的测量方法,对三缸发动机分解摩擦功的测量流程以及测量结果的有效性进行分析对比,以此来达到分解摩擦功试验的试验目的,为三缸发动机的降摩擦节油设计提供有效方向;此次试验研究主要从电力测功机测量精度标定、零部件摩擦损失功测量方式及注意事项等方面进行研究分析并给出试验结果.     

工业机器人单目双视的应用研究

工业机器人单目双视系统充分利用机器人位姿便于调整的优势,在机器人带动摄像机一起运动过程中,对包含工件的场景进行多次图像采集,实现目标点三维坐标的识别。论文介绍了机器人摄像机的非线性快速补偿算法的定标原理,给出了机器人单目双视三维检测实验。单目双视结合工业机器人控制软件,可使工业机器人能实时调整运动轨迹也可对工件进行非接触测量,提高了工业机器人的适应性和灵活性。     

基于道路标线的交通事故现场摄影测量研究

论述了基于普通相机的交通事故现场测量技术基本理论,提出了一种利用道路标线作为标定参考物的新的标定方法,在小波多尺度边缘检测基础上,利用Harris角点提取对图像进行分析处理,对影响摄影测量精度的有关参数进行了简要描述,对一个实际事故现场的部分数据进行了分析,验证了设计的算法。     

MEPDG路基土动态回弹模量预估模型参数标定——以山西省河运高速公路为例

为了得到某地区回弹模量的预估方程,采用英国GDS室内重复加载三轴试验系统研究了山西省河运高速公路黄土路基土在3种含水率(OMC-3％,OMC和OMC+3％)和3种压实度(91％,96％和100％)水平下的动态回弹模量值.试验方法采用AASHTO路基土与粒料回弹模量试验方法(T307-99)制定的三轴重复加载试验方法.利用测试得到的135个回弹模量值和对应的应力水平对力学经验法路面设计指南(MEPDG)推荐的路基土回弹模量预估模型进行了非线性回归参数标定,得到了研究地区的动态回弹模量预估表达式.     

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.     

Enhancing the performance of existing urban traffic light control through extremum-seeking

Urban traffic light controllers are responsible for maintaining good performance within the transport network. Most existing and proposed controllers have design parameters that require some degree of tuning, with the sensitivity of the performance measure to the parameter often high. To date, tuning has been largely treated as a manual calibration exercise but ignores the effects of changes in traffic condition, such as demand profile evolution due to urban population growth. To address this potential shortcoming, we seek to use a newly developed extremum-seeker to calibrate the parameters of existing urban traffic light controllers in real-time such that a certain performance measure is optimised. The results are demonstrated for three categories of traffic controllers on a microscopic urban traffic simulation. It is demonstrated that the extremum-seeking scheme is able to seek the optimal parameters, with respect to a certain performance measure, for each of these traffic light controllers in an urban, uni-modal traffic environment.