萨伯公司多光谱伪装网

美国特种部队与萨伯公司联合研制的安装枪炮车辆（GMV）系统可以对抗多光谱威胁,包括可见光、近红外、热红外和宽波段雷达．其多光谱特性可以确保被保护平台与周围背景环境很好地“融为一体”,可以在任何气候条件下降低目标照射雷达（TIR）的探测,降低热传感器的探测与识别能力,可避免被先进的武器系统锁定．     

汽车数字化标准信源系统识读距离仿真

为实现汽车数字化标准信源系统的采集基站建设和标签安装的最优配置,对无源射频识别（RFID）车辆身份管理系统的识读距离进行了仿真计算。在读写器天线与标签天线远场图确定的条件下,对采集基站的架设参数,例如天线的安装倾角,仿真计算得到目标车辆通过固定式龙门架无源RFID采集基站时的可识读距离,并进行比较分析。为汽车数字化标准信源系统不同车型的标签安装位置以及采集基站的架设提供了参考依据。     

改进希尔伯特-黄变换分析波磨对列车时频特征的影响

本文旨在研究钢轨波浪形磨损对列车时频特征的影响.建立了车辆/轨道空间耦合模型,模拟计算了钢轨短波、长波波磨激励下车辆系统的动力响应.将集成经验模态分解（Ensemble Empirical Mode Decomposition,EEMD）和正交希尔伯特变换（Normalized Hilbert Transform,NHT）应用于车辆/轨道耦合系统的振动信号分析中,分析了不同波深和波长的波磨对转向架动力响应时频特征的影响.结果表明：波磨会引起车辆系统振动响应的频率调制,频率振幅与平均频率之比可作为轮轨冲击的预警指标.     

飞思卡尔芯片驱动下一代汽车车身电子应用

电子安全系统由于影响巨大,在不断进行升级．国际标准组织（ISO）和国际电工委员会（IEC）制定了新的要求。功能安全标准IEC61508及其未来车辆自适应标准IS026262,现已在业内应用,以确保车辆电子系统充分的安全性。该ISO文档定义了4个车辆安全完整性等级（ASIL）,其中ASILD代表最高安全级别。而飞思卡尔半导体推出的SafeAssure计划。旨在帮助系统制造商更加轻松地满足汽车和工业市场中的功能安全标准要求。     

基于连续波雷达的交通信息采集系统研究

以线性调频连续波（LFMCW）雷达参数估计理论和雷达高分辨距离像（HRRP）识别理论为基础,介绍了适用于车辆信息提取的采集系统设计方案,提出基于支持向量机（SVM）算法在车辆类型识别上的应用问题,采用实验数据验证了该方案的有效性和易于推广性。     

射频识别技术及其在交通领域的应用

射频识别（RFID）技术采用大规模集成电路技术，识别技术，计算机及通信技术，通过读写器和安装在载体（车辆或设备或人员）上的RFID卡，构成RFID系统，实现对载体的非接触的识别和数据信息交换，RFID技术已广泛应用于交通、公安，路政、物流管理等领域，本文介绍该技术在交通领域的几个主要应用。     

不停车车辆出入管理系统设计与实现

在单位的出入口安装不停车车辆出入管理系统,可以保证本单位车辆的安全,便于随时了解车辆的进出状况,从而进行有效的管理。设计一套适合于学校大门口的不停车车辆管理系统,基于有源RFID技术,可以进行远距离识别、比对,使合法车辆快速通过,实现车辆出入安全自动化管理,介绍了系统的组成、原理以及门禁控制器和管理软件的设计与实现。     

图像自动识别技术在轨道车辆检测中的应用

在轨道车辆检测中应用图像处理和模式识别,可提高车辆检测效率,对轨道车辆的安全运行具有重要意义。本文旨在对采集的轨道车辆侧底部的裙底板3D图像,运用图像配准,图像对比,霍夫圆检测,神经网络等,通过当前采集的图像与模板图像比对实现轨道车辆裙底板进行自动检测。内容包含:图像的采集方式,模板数据库的建立,部件定位,以及通过对异常识别实例证实图像处理算法与轨道车辆部件检测之间的联系。     

准时的重要性：为嵌入式列车控制系统选择操作系统

为确保安全和效率,铁路和运输系统正在实施各种保护系统,如列车自动保护（ATP）、积极列车控制（PTC）和基于通信的列车控制（CBTC）等。地铁和其他轨道交通系统正在采用自动列车操作（ATO）系统并运行＂无人驾驶＂列车（没有驾驶员或驾驶员只用来处理紧急情况的列车）。这些控制系统与安全息息相关。它们必须满足IEC61508和EN 5012x标准中所设定的严格可靠性要求。     

“汽车数字化标准信源”标签安全研究

＂汽车数字化标准信源＂（即电子车牌）系统依靠UHF频段的射频识别（RFID）标签记录车辆的基本信息,同时凭借架设在道路上的专用读写设备采集车辆、道路等相关信息,以实现对车辆的跟踪定位、实时管理、交通管理、环保、保险状态监察等功能。介绍了＂汽车数字化标准信源＂系统车辆专用UHF频段标签内存数据的不同类型和如何通过ISO18000-6B标签的特性及有效加密手段满足系统对信息安全及隐私保护的需求,提出了一套有效的标签信息安全加密设计方案。     

一种基于DMA的汽车制动检测台驱动电机控制策略

在利用滚筒反力式制动性能检测台对汽车制动性能进行检测的过程中,由于粘砂滚筒附着系数较高,汽车在制动时,轮胎与滚筒之间会产生很大的摩擦力,容易发生剥胎现象。因此,合理采集汽车制动性能相关参数的同时,及时关停制动性能检测台驱动电机以保证被检车辆的安全,成为汽车制动性能检测的关键技术之一。通过对现有的汽车制动性能检测中各种控制方法优缺点的比较,提出了一种基于DMA的汽车制动检测台驱动电机控制方法,提高了控制的实时性和灵活性,在采集到汽车制动性能相关参数的同时,最大限度地保护了车辆安全。试验结果表明,该控制策略稳定有效,检测精度高,具有较高的实用性。     

同频邻频干扰下1.8GHz频段CBTC工作频段和布站间隔优化

现行基于通信的列车自动控制系统(CBTC)部署于2.4 GHz免执照频段,易受手持Wi-Fi热点干扰,已造成深圳和北京多起地铁紧急制动事故.在1785～1805 MHz频段同频邻频先用通信系统的干扰下,为CBTC系统选择合适的部署频段、工作带宽和布站间隔,提高其系统吞吐量并降低紧急制动概率十分必要.针对该问题,首先通过分析确定干扰研究场景,并基于确定性计算的方法得到干扰方和CBTC列车端之间的安全隔离,随后通过系统级仿真比较不同条件下CBTC系统下行链路的吞吐量和CBTC系统紧急制动概率,得到适合CBTC部署的工作频段、带宽和布站间隔.     

Nonlinear brake control for vehicle CW/CA systems

A brake control law for vehicle collision warning/collision avoidance (CW/CA) systems has been proposed in the paper. The control law has been designed for optimized safety and comfort. A solenoid-valve-controlled hydraulic brake actuator system for the CW/CA systems has been investigated. A nonlinear computer model and a linear model of the hydraulic brake actuator system have been developed. Both models were found to represent the actual system with good accuracy. Uncertainties in the brake actuator model have been considered in the design of the control law for the robustness of the controller. The effects of brake control on CW/CA vehicle response has been investigated via simulations. The simulations were performed using a complete nonlinear vehicle model. The results indicate that the proposed brake control law can provide the CW/CA vehicles with an optimized compromise between safety and comfort     

Distributed congestion control strategy using network utility maximization theory in VANET

Cooperative vehicle safety system (CVSS) rely on periodical beacons to track neighboring vehicles.High traffic density often causes channel congestion,seriously damaging the performance of CVSS.Existing congestion control strategies aim to ensure the performance in network layer,without considering the service requirements of vehicles in different driving contexts.To solve the problem,a distributed congestion control strategy using network utility maximization (NUM) theory was proposed.First of all,the NUM model for channel resource allocation was introduced.A utility function reflecting vehicle’s safety requirements was proposed in the model.Then under the condition of fixed transmit powers,a optimization problem of channel resource allocation was proposed.Lastly,to solve the optimization problem,a distributed congestion control algorithm named utility-based rate congestion control (UBRCC) algorithm was designed,the algorithm worked out the optimal beaconing rate by updating vehicle’s congestion price,realizing the resource allocation according to vehicle’s safety requirements.Simulation results validate that UBRCC algorithm can efficiently control channel congestion,reduce transmission delay,ensure reliable data transmission and satisfies the requirements of safety applications.     

Strategies and spacing requirements for lane changing and mergingin automated highway systems

In automated highway systems (AHS) vehicles are expected to operate using their own sensing and control systems by interacting with other vehicles and the infrastructure in a way that guarantees safety, stability, and high capacity. We examine various alternative scenaria for merging and lane changing and we present an algorithm for calculating the minimum safety spacing for lane changing (MSSLC); that is, we calculate the intervehicle spacing that the vehicles should maintain during a merging or lane changing maneuver so that in the case where one of the vehicles executes an emergency braking manuever, the rest of the vehicles have enough time and space to stop without any collision taking place. The calculation of the MSSLCs for merging or lane changing maneuvers is more complicated than the calculation of the minimum safety spacing for a longitudinal vehicle following since, in the former case we have to take into account the particular lane-changing policy of the merging vehicle as well as the effect of combined lateral/longitudinal motion during the lane changing maneuver. The braking profiles of the vehicles involved in an emergency scenario during a lane changing maneuver depends on the particular AHS operational concept, i.e., on the degree of communication between the vehicles and between the vehicles and the infrastructure. We consider six different AHS operational concepts; for each concept we consider possible emergency braking profiles and we investigate the effect of the particular operational concept on the MSSLC     

Optimal robust control of a contactless brake system using an eddy current

As vehicle speed increases, a more powerful brake system is required to ensure vehicle safety and its reliability. A contactless eddy current brake (ECB) is developed to take the superior advantages of fast anti-lock braking to the conventional hydraulic brake systems. Braking torque analysis is performed by using an approximate theoretical model and the model is modified through experiments to have a more reliable result. Designs of an ECB for a scaled model for demonstration and actual vehicle model are performed. Optimal torque control which minimizes a braking distance is achieved by maintaining a desired slip ratio corresponding to the road condition. Optimal controller which is robust to the varying road friction coefficients is designed by using a sliding mode controller. Simulation and experimental results for a scaled model are presented to investigate the performance of a contactless ECB.     

汽车超载监测系统

为了实时识别各种车型的超载车辆,该系统基于开源计算机视觉库(OpenCV),先根据车辆照片库建立车型分类器,然后使用数字摄像机拍摄进入监控区域的车辆,在视频中使用分类器识别车型,根据所识别得到的车型去查询数据库获得该车型的核载,再通过动态称重技术获得车辆的实际载重,及时判别车辆是否超载。此方法可避免过去使用统一重量衡量不同车型是否超载的弊端,并可同时免线圈测量车速。测试结果表明系统能快速准确地识别出车型。配合动态称重系统,就能实时得出所通过的车辆是否超载,对公路养护和道路交通安全有相当大的实用意义。     

汽车防抱死制动系统常见故障诊断

制动系统是汽车的一个重要组成部分,是保证行车安全极为重要的一个系统,它的好坏直接影响车辆的平均车速和车辆的运输效率。为保证制动效果的有效发挥;为保证汽车紧急情况具有转向操作能力;为提高车辆的安全性能,故在车辆内部加装了防抱死制动系统(简称ABS)。本文对汽车防抱死系统的组成、工作原理及常见故障进行分析、排除诊断。     

Automobile Brake-by-Wire Control System Design and Analysis

The automobile brake-by-wire (BBW) system, which is also called the electromechanical brake system, has become a promising vehicle braking control scheme that enables many new driver interfaces and enhanced performances without a mechanical or hydraulic backup. In this paper, we survey BBW control systems with focuses on fault tolerance design and vehicle braking control schemes. At first, the system architecture of BBW systems is described. Fault tolerance design is then discussed to meet the high requirements of reliability and safety of BBW systems. A widely used braking model and several braking control schemes are investigated. Although previous work focused on antilock and antislip braking controls on a single wheel basis, we present a whole-vehicle control scheme to enhance vehicle stability and safety. Simulations based on the whole-vehicle braking model validate a proposed fuzzy logic control scheme in the lateral and yaw stability controls of vehicles.     

基于驾驶数据的主动安全预警系统设计

随着人们生活水平的提高,车辆的安全性越来越成为人们共同追求和关注的焦点。在“人-车-路-环境”的交通系统中以信息技术为主导的车辆主动安全预警系统是解决车辆驾驶安全问题的最佳方法。文章基于驾驶数据得到驾驶人驾驶风险评估,依据峰值触发系统报警,有效保障了车辆全过程安全行驶,避免交通事故发生。