基于机器视觉的车道偏离预警系统的实现

目前高速公路上由于车道偏离而导致的交通事故造成了巨大的损失,从而使得车道偏离预警系统的研究成为了社会的一大热点.本文基于DSP计算和FPGA计算,构造出一套基于视觉的车道偏离预警系统.本文给出了系统的框架结构以及硬件实现方式,并基于所提出的系统详细研究了视觉系统中大容量数据的传输、存储和处理等问题.最后,基于构造的系统,通过一系列典型的视觉处理算法和应用于车道跑偏决策的软件算法,验证了系统的可行性.     

基于视频的高速车道偏离预警系统

在驾驶过程中发生非意识车道偏离时,偏离预警系统采用报警方式保障行车安全。针对高速公路频发的车道偏离事故,设计和实现了基于视频处理的高速车道偏离预警系统(Highway Departure Warning System,HDWS)。算法处理上,分别进行感兴趣区域(Area of Interest,AOI)设定、图像预处理和Otsu自适应阈值二值化,应用直线模型和改进Hough变换提取车道线,采用像素距离与车道线斜率信息融合的偏离决策,并在MATLAB R2015a上仿真测试。仿真结果表明,该系统能提前1.2 s报警,准确率高于95%,漏报率低于3%,满足高速道路环境下偏离预警性能要求。     

基于OpenCV的嵌人式车辆驾驶偏离报警系统

为减少因驾驶员无意识偏离车道行驶造成的交通事故,基于ARM和OpenCV建立嵌入式车道偏离报警系统。重点介绍了系统的设计、平台的搭建和算法处理流程。该系统通过摄像头采集获取图像信息,并应用OpenCV对图像进行预处理,通过提取图像中车道线信息,评估车辆行驶状态是否偏离车道中心位置,根据车辆的行驶状态,发出报警,提醒车辆驾驶人员当前行驶偏离情况,以达到辅助安全驾驶的目的。     

人机共驾智能车辆车道偏离横向辅助控制仿真

车道偏离辅助控制对于提高人机共驾智能车辆行驶安全性具有重要的现实意义,为此进行人机共驾智能车辆车道偏离横向辅助控制仿真研究.对车道线进行识别与跟踪,并采用基于车辆当前位置和基于车辆跨越车道线时间的联合算法进行智能车辆车道偏离判断;建立车辆系统模型和驾驶员模型,并通过基于转向和制动的可拓联合方法实现车辆偏离的横向辅助控制.实验结果表明,所研究方法在转向反应时间、车道偏离持续时间、最大转向角速度与最大横向偏离量四个指标的表现上更好,人机共驾智能车辆车道偏离横向辅助控制效果更佳.     

车道偏离预警系统关键技术设计

车道偏离系统是一种安全辅助驾驶系统,针对传统车道偏离预警系统实时性不足,设计了基于改进Sobel算法和Hough变换识别车道线的实时车道偏离预警系统。系统将摄像机采集的道路图像经过改进Sobel算法处理,能更快得到车道线边缘像素信息,再应用Hough变换连接有效边缘像素确定车道线位置,最后通过与预警决策模块的匹配度实现车道偏离的预警判定。经测试系统性能良好。     

基于TMS320DM6437的车道偏离报警系统设计

据统计约有50%的汽车交通事故是因为汽车偏离正常的行驶车道引起的,如果在驾驶员无意识偏离原车道时提前预警,则可以大大减少因车道偏离引发的碰撞事故。因此,本文以TI公司推出的达芬奇系列多媒体图像处理器TMS320DM6437为核心,设计了一套嵌入式车道偏离预警系统。本文给出了车道偏离预警系统的结构及工作原理,阐述了硬件设计和软件设计实现方法。实验证明,该系统具有较好的实时性和较高的车道偏离预警准确率,能够满足车道偏离预警要求。     

基于图像处理的车道偏离的研究和实现

利用ADI公司的DSP评估板,结合数字图象处理技术,设计出了一套实用的车道偏离检测系统平台.该系统采用两个CMOS摄像头采集图像信号,输入到DSP评估板中,先利用图像平滑技术滤除噪声,然后采用边缘检测技术识别出车道识别线,结合速度传感器、转向传感器的信号判断汽车是否将要偏离跑道,在LCD模块中,并实时显示车的偏离状态.如果将要偏离或者已经偏离,就会有蜂鸣震动提示.     

基于中间件的高速公路车道控制收费系统的设计

分析了目前常用的基于二层架构的C/S模式的高速公路车道收费系统现状,指出其存在的不足,提出并实现了基于中间件的三层体系结构的高速公路车道控制收费系统,详细介绍了系统的结构、功能、业务流程及关键技术。该系统已在多个收费站成功投运,至今运行情况良好,性能可靠稳定。     

基于DSP的嵌入式车道偏离报警系统的硬件平台

目前普遍采用的车道偏离报警系统的硬件平台是工业PC.为了克服其体积大、功耗高、成本高、可靠性低的缺陷,设计了一种嵌入式车道偏离报警系统的硬件平台.利用基于DM642系统作为视频采集处理模块,采用C8051F040的数据采集系统作为汽车行驶参数采集模块,使用基于LM2576的电源系统为整个系统供电模块.试验表明,该系统具有良好实时性和抗干扰能力,满足了系统设计需要.     

高速公路车道收费与控制系统的实现

介绍了高速公路收费系统中车道收费及控制系统实现的关键技术。重点论述了车道收费及控制系统的设计、数据传输和外场设备控制等方面的内容。     

逆透视投影下车道偏离时间的在线估计

提出了一种基于图像逆透视变换后的车道偏离时间的实时在线估计算法。该算法先对道路图像进行预处理,得到二值化的道路图像,然后通过逆透视变换方法消除图像的透视效果,用Hough变换方法检测车辆所在车道的左右道路标志线,最后估算车辆偏离车道的时间,判定车辆是否会偏离车道。对该算法进行了详细介绍并给出了实验结果,结果表明该算法能够准确地判断车道偏离。     

嵌入式车道跑偏告警系统设计

为提高汽车驾驶的安全性,减少高速公路上由于车道跑偏而造成的巨大损失,基于DSP计算和FPGA计算,构造出一套基于视觉的嵌入式车道跑偏告警系统.重点介绍了系统的框架结构以及硬件实现方式,详细研究并解决了视觉系统中大容量数据的传输、存储和处理而造成的带宽问题,采用FPGA内部构造FIFO及DSP上支持的PDT传输方式,加快总线上的数据传输,提高总线的利用率,满足系统的实时性要求.最后,基于构造的系统,设计了典型的视觉处理算法和应用于车道跑偏决策的软件算法,验证了系统的可行性.     

Does False and Missed Lane Departure Warnings Impact Driving Performances Differently?

Lane Departure Warning Systems (LDWS) are known to be effective at preventing lane departures. The current study aimed to further investigate the influence of LDWS incorrect warnings along with the warning onset on driving performances. Performances were considered during missed warned lane departure episodes, as well as correctly warned lane departure episodes following incorrectly warned (false or/and missed warning) episodes. In the reported experiment, the incorrect warnings order of presentation was manipulated along with the warning onsets (partial and full lane departure). Results pointed out that a missed warning is impairing driving performances during the missed warned situation, whereas a false warning is impairing driving performances for the subsequent lane departure. Moreover, if false warning impairment is magnified by the occurrence of a subsequent missed warning, this multiplicative effect is restricted to the following lane departure only. These findings bring both theoretical and practical insights. From a theoretical perspective, the human–machine cooperation LDWS model was refined by the adjunction of a transitional influence of incorrect warnings on the information processing. From a practical perspective, the recommendation to avoid false warnings as much as missed warnings was made.     

The impact of false warnings on partial and full lane departure warnings effectiveness and acceptance in car driving

In the past, lane departure warnings (LDWs) were demonstrated to improve driving behaviours during lane departures but little is known about the effects of unreliable warnings. This experiment focused on the influence of false warnings alone or in combination with missed warnings and warning onset on assistance effectiveness and acceptance. Two assistance unreliability levels (33 and 17%) and two warning onsets (partial and full lane departure) were manipulated in order to investigate interaction. Results showed that assistance, regardless unreliability levels and warning onsets, improved driving behaviours during lane departure episodes and outside of these episodes by favouring better lane-keeping performances. Full lane departure and highly unreliable warnings, however, reduced assistance efficiency. Drivers’ assistance acceptance was better for the most reliable warnings and for the subsequent warnings. The data indicate that imperfect LDWs (false warnings or false and missed warnings) further improve driving behaviours compared to no assistance.

Practitioner Summary: This study revealed that imperfect lane departure warnings are able to significantly improve driving performances and that warning onset is a key element for assistance effectiveness and acceptance. The conclusion may be of particular interest for lane departure warning designers.     

基于视觉的车道跑偏检测方法研究及仿真

为了保证辅助驾驶技术行车的安全,在分析了基于视觉的车道跑偏检测方法的具体步骤的基础上,首先提出了利用由计算机视觉获得的车道标志线来进一步获得车-路关系的方法,并推导了几种车道跑偏判据TLC(time to lane crossing)的计算公式;然后利用“预瞄最优曲率模型”来仿真人-车-路的关系,并验证了当人的状态发生变化时,TLC判据可以有效地提供报警的效果;最后在红旗自主驾驶样车的视觉导航系统中进行了实验,实验结果表明,上述分析和仿真是可行的。     

基于双曲线模型的车道识别与偏离预警

针对车道识别与偏离预警算法在准确性、可靠性和计算效率方面存在的问题,提出一种基于双曲线模型的车道识别与偏离预警算法。首先,在图像预处理基础上通过特征点搜索筛选道路边缘点,采用双曲线构建道路模型,利用最小二乘原理拟合道路参数,再根据拟合车道线及邻近点信息构建车道置信度函数,将置信度大于设定阈值的车道线作为最终检测结果;然后,根据相邻帧车道线连续变化的特点,在前帧拟合道路线附近使用粒子滤波算法进行道路边缘点筛选、拟合以及置信度计算,实现对车道线的跟踪;最后,在图像坐标系中建立时空联合预警模型,对车道偏离行为进行预警。在PC平台上进行的算法实现与道路实验结果表明:所提方法在一般路况下,具有92%的车道识别和偏离识别正确率和40ms/帧的平均处理速度,满足车道偏离预警应用要求。     

一种基于扫描线和区域生长的行车偏移检测算法

驾驶疲劳是引发高速公路车祸的重要原因之一,而根据行车偏移信息则可以评估疲劳状态。为了实时检测到行车偏移信息,提出了一种基于扫描线与区域生长相结合的视频图像分析算法,从而实现了多种道路车道标线和行车偏移的自动检测。该算法还采用自适应感兴趣区域选择方法以及根据车道状况确定帧处理策略的方法,使运算速度满足实时要求。采用该方法获得的行车偏移信息将给后续的驾驶疲劳分析提供必要的数据。     

Identification of driver state for lane-keeping tasks

Identification of driver state is a desirable element of many proposed vehicle active safety systems (e.g., collision detection and avoidance, automated highway, and road departure warning systems). In the paper, driver state assessment is considered in the context of a road departure warning and intervention system. A system identification approach, using vehicle lateral position as the input and steering wheel position as the output, is used to develop a model and to update its parameters during driving. Preliminary driving simulator results indicate that changes in the bandwidth and/or parameters of such a model may be useful indicators of driver fatigue. The approach is then applied to data from 12 2-h highway driving runs conducted in a full-vehicle driving simulator. The identified model parameters (ζ ω_n , and DC gain) do not exhibit the trends expected as lane keeping performance deteriorates, despite having acceptably white residuals. As an alternative, model residuals are compared in a process monitoring approach using a model fit to an early portion of the 2-h driver run. Model residuals show the expected trends and have potential in serving as the basis for a driver state monitor     

Shared control for lane departure prevention based on the safe envelope of steering wheel angle

The ability to prevent lane departure has become an important feature for commercialized vehicles. This paper proposes a shared steering assistance strategy based on a safe envelope of steering wheel angle (SWA). This solves the human-machine conflict issue in lane departure prevention (LDP) system which uses steering control to help the driver keep the vehicle within the correct lane. The system combines a driver steering control model, current vehicle states and vehicle-road deviation. The desired SWAs are calculated when the driver intends to drive along the left or right side of the lane, and then the two angles are used to generate the safe envelope. Next, a driver intention estimator is designed to predict driver’s intended SWA and the assistance control is activated by judging whether the driver intended SWA is go beyond the safe envelope. Finally, a H∞ controller and a disturbance observer are developed to determine the assistance torque. In this way, the SWA is limited to safe values to mitigate lane departure and the controller intervention is minimized. The effectiveness of the proposed method is evaluated via numerical simulation with different driving scenarios and human-in-the-loop experiment on a driving simulator. The obtained results show that this method not only can avoid lane departures effectively, but also ensures a good human-machine cooperative performance.     

高速公路车道收费系统通用化设计与实现

该文针对目前高速公路收费系统开发周期长、可维护性差等缺点,设计和实现了基于组件和框架复用技术的通用化车道收费系统,开发人员可以在这个系统上进行二次开发,从而大大缩短了开发周期,减少了开发成本。