基于激光测距的汽车防碰撞系统设计

设计一款汽车主动防护的激光测距防碰撞系统。该系统利用激光探测前方路况,并通过单片机控制预警和防撞系统,帮助驾驶者对险情提前进行预判并采取相关措施(报警或者自动制动)。经仿真表明:该系统可以有效地减少汽车在公路上追尾碰撞等事故。     

基于单目视觉的智能车障碍物检测及测距算法研究

在自动驾驶场景下,为了实现对智能车辆前方障碍物进行目标检测及测距,提出了一种基于单目视觉的前方车辆及行人检测与测距方法.利用数据集对YOLOv3神经网络模型进行优化训练,利用训练完成的神经网络对实时采集的视频信号中的车辆及行人进行目标检测,输出车辆及行人目标的检测框.以目标检测框底部中心点为参考点,根据相似三角形测距算...     

基于SOPC的汽车测距限速系统设计

为提高行车安全性,提出了一种基于SOPC技术的汽车激光测距限速系统。该系统利用单目标测距原理,可对前方车辆进行自动激光测距,依据不同车速所对应的不同安全距离完成声光报警及车速限制。最后在SOPC开发平台中进行设计,验证了该系统具备测距限速功能。     

基于单目视觉的前方车辆检测与测距方法研究

提出了一种基于单目视觉的前方车辆检测与测距方法.首先利用自适应闻值分割方法得到车辆底部阴影特征,同时采用区域融合方法解决车辆边缘变形问题,得到疑似车辆区域,然后在疑似区域内利用车辆对称性进行验证,得到准确车辆区域,最后利用基于摄像机内部参数和几何关系的单目视觉测距方法得到本车与前方车辆之间的距离.实验结果表明,该方法能...     

基于激光测距传感器的汽车防撞报警器的设计

介绍了一种基于激光测距传感器的汽车防撞报警器的设计原理。在车体上合理布置这些传感器,利用反射激光测量待测距离,实现汽车前行和倒车时对障碍物距离的检测、实时显示和报警,使汽车避免和障碍物发生碰撞。实践表明该汽车防撞报警器具有测距速度快、准确度高、易于实现等优点,具有很好的应用前景。     

基于概率假设密度的汽车防撞雷达多目标跟踪

基于毫米波汽车防撞雷达系统,考虑到雷达测量误差的存在以及道路前方车辆的行驶状态和数目的实时变化,包括新目标车辆出现、目标消失等多种情况,设计了一种多模型高斯混合概率假设密度算法实现对多个机动车辆的检测跟踪。针对高速公路上多个车辆行驶的情况,运用高斯混合概率假设密度算法以及多模型理论进行仿真实验,结果表明该算法不仅能够实时地对雷达探测范围内多个目标车辆进行准确跟踪,而且能够及时地判断出驶入或驶出雷达探测范围的车辆,从而在提高自车与前车之间相对距离、相对速度测量精度的同时,有效地对可探测目标车辆数目进行准确的判断,降低了雷达虚警率,提高了防撞雷达系统的可靠性。     

面向车辆盲区防撞系统的交通目标智能检测

交通目标智能检测是车辆盲区智能防撞系统中的基础技术,该技术的研究和应用对降低交通事故损失具有重要意义.本文面向车辆盲区防撞系统设计的交通目标智能检测,其在基础模型中融合了两个性能提升策略.将该模型应用于国内和国外道路场景检测数据集,以验证模型在所有范围和近距离目标的检测性能.实验结果表明该模型可以对近距目标表现出较高的...     

复杂行车环境下的前方车辆检测算法研究

针对复杂行车环境下的智能车辆行车安全问题,提出了一种基于特征的多目标前方车辆检测算法。算法首先利用车辆底部阴影特征、车辆轮廓特征的先验知识,探测前方感兴趣区域,然后利用车辆边界特征、对称性特征对感兴趣区域进行判别。该算法针对复杂路况下的车辆分布特征进行了适应性设计。能够快速、准确的检测到具有潜在安全威胁的前方行驶车辆。     

基于车底阴影的车前障碍物检测

基于计算机视觉的道路车辆检测是智能车辆导航的核心问题,实时准确地检测前方运动车辆的位置信息是车辆安全驾驶的前提。文中采用车底阴影的前方运动车辆检测算法,在基于车道线检测的基础上,通过车底阴影检测,实时准确地检测前方车辆。该算法通过使用Otsu阈值分割提取出车道线,生成AOI区域,再进行两次自适应阈值分割提取车底与路面的交线,从而检测出前方运动车辆。经过在高速公路上对运动车辆检测实验证明,该算法基本满足车辆安全驾驶的需求,并能准确实时地检测出前方运动车辆,进而减少了交通事故的发生。     

基于激光测距的船舶防撞定位系统设计

介绍一种基于激光测距的船舶防撞定位报警系统的设计原理,给出了系统的硬件设计和程序设计方法.在船舶上合理布置激光测距传感器,利用反射激光测量待测距离.实时自主的监测目标船舶与周围船舶的距离和方位.当进入待测领域的船只与目标船舶达到设定的安全距离时,实现声光报警,避免船舶相撞.由于整个系统的经济性和精确性,适合中小船舶的需求.     

基于车车通信的车辆防碰撞算法

为了提前预测车辆碰撞事故和降低碰撞事故发生概率,提出了基于车车通信的车辆防碰撞算法（VACA）。VACA根据自身和周围邻居车辆的北斗位置坐标,在水平和垂直两个方向上分别采用Kalman预测算法预测下一时刻的车辆行驶状态,采用数据预判断方法直接确定一定发生碰撞或不发生碰撞的情况。当不能直接判断时,则计算加速度可变下的安全距离,建立和求解碰撞状态预测模型,获得碰撞预测时间最小值。如果该最小值小于阈值,则发出报警信号提醒驾驶员。仿真结果表明,与基于车辆间通信的智能防碰撞报警模型（IVCWM）和车辆提前预警的防碰撞算法（ECWA）比较,VACA可提前发现碰撞情况,而且更准确,有一定的应用价值。     

基于激光传感器的自主寻径智能车设计

设计了一种基于激光传感器的自主寻径智能模型车系统,以飞思卡尔公司16位单片机MC9S12XS128为核心控制器;系统采用激光传感器阵列检测路径信息,得到智能车与路径的横向偏差,采用比例控制算法控制舵机转向,并对直流驱动电机进行增量式PID闭环调节控制,从而实现智能模型车快速稳定地自主寻径行驶。     

Experimental Assessment of the RESCUE Collision-Mitigation System

Road-traffic-incident analysis has shown that 52% of incidents are caused by a collision between two vehicles or between a vehicle and an obstacle. In this paper, the REduce Speed of Collision Under Emergency (RESCUE) collision-mitigation system (version 1.0) is presented and evaluated toward various typical road situations. The aim of the RESCUE system is to decrease the kinetic energy dissipated during a collision through automatic emergency braking that occurs 1 s before the collision. This emergency braking is triggered by an alarm coming from a decision unit taking into consideration the results of a generic obstacle-detection system-based on fusion between stereovision and laser scanner-and a warning area in front of the vehicle. The different subsystems are presented. Then, the behavior of the RESCUE collision-mitigation system toward various typical dangerous road situations is assessed through systematic tests. These quantitative tests are completed by qualitative ones carried out on 737 km of open roads (freeways, highways, rural roads, downtown) to provide a more precise idea about the false-alarm rate. The experiments show the system is promising in terms of reliability, genericity, and efficiency     

A Resilient and Scalable Flocking Scheme in Autonomous Vehicular Networks

Vehicular Ad hoc NETworks (VANET) is emerging as a highly promising technology, which aims to provide road safety, environment protection and personal-oriented services. The vehicle ad hoc wireless communications form an indispensable part of truly ubiquitous communications networking. VANET is formed by spontaneously moving autonomous vehicles with the self-organization and self-management capability. In this paper, we focus on the decentralized coordination of multiple unmanned vehicles such that they can freely move and adaptively cooperate in a complex environment. During this procedure, flocking is one of the key operations and requirements. Here, flocking refers to the formation and maintenance of a desired pattern by a group of mobile vehicles without collision during movement. We propose a resilient and scalable flocking scheme for a group of vehicles, which follows the leader–followers moving pattern. In the absence of obstacles, a collision avoidance algorithm is presented to maintain a desired distance among vehicles. This will ensure information completeness and is significant in certain mission critical situations without collision between a unmanned vehicle and its neighboring vehicles. In the presence of obstacles in an environment, this algorithm is able to avoid collision between a vehicle and its neighbor (either a neighboring vehicle or a neighboring obstacle). Theoretical proof has been presented to demonstrate the effectiveness and correctness of the algorithm to guarantee collision-free. In addition, with increasing number of vehicles, the performance of the proposed flocking scheme performs without increasing the processing overhead, which demonstrates the desirable scalability.     

多目标LFMCW车载前向防撞雷达的实现

为主动减少高速公路上碰撞事故的发生,提出一种基于FPGA和DSP芯片的车载前向防撞雷达系统的实时处理方案。分别介绍了LFMCW雷达的基本原理、系统硬件架构、信号处理流程,给出了实测数据的结果分析。系统采用MTD-频域配对法来实现对目标参数的估计,实测数据结果不仅验证了算法的有效性,而且表明系统能够准确实时地检测出前面目标车辆的距离与速度信息。该方法可以应用到LFMCW防撞雷达系统当中,从而给驾驶员提供前方道路行驶参考,以达到减少交通事故的目的。     

基于卡尔曼滤波算法的城市交叉路口车辆检测及分类

为了向相关部门提供更多的过往车辆信息以满足道路交通的需求,设计了一个基于卡尔曼滤波算法的城市交叉路口车辆检测及分类系统,用于对过往的车辆进行检测、计数和分类.首先采用背景差分法和卡尔曼滤波算法对在检测区的车辆进行检测和跟踪;然后使用经过检测、处理的被测车辆图像触发距其最近的相机进行图形分割;最后,通过LDA分类器对分段车辆的几何形状及外观特征进行正确地分类.所提系统的有效性在摄取的3400帧视频序列上得到了验证,实验结果表明,系统的检测率可达97.44％,正确分类率可达88.0％,与先进的方法相比,取得了更好的检测性能.     

Novel Collision Detection and Avoidance System for Midvehicle Using Offset-Based Curvilinear Motion

In recent days, the manufacture of automotive vehicles is dramatically enhanced worldwide. Most vehicle crashes are due to the drive distraction on the real highway roads and traffic-density. In this proposed method, a novel collision detection and avoidance algorithm are coined for Midvehicle Collision Detection and Avoidance System (MCDAS), addressing two scenarios, namely, (a) A rear-end collision avoidance with host vehicle under no front-end vehicle condition and (b) offset-based curvilinear motion under critical conditions, while, suitable parallel parking manoeuvring also addressed using offset-based curvilinear motion. The Monte Carlo analysis of the proposed MCDAS is demonstrated using the Constant Velocity (CV) manoeuvring strategy and simulated with real-time data using the NGSIM database.

     

Hierarchical Longitudinal Controller for Rear-End Collision Avoidance

Rear-end collision is a very serious problem in modern traffic situations, and there have been a great number of research reports on the longitudinal control method for road vehicles. In many cases, however, the control problem is formulated under platoon configuration and for some predictable noncollision situations. For predictable collision situations, regional and hierarchical approaches have been employed, but these approaches render difficulties due to ignorance for modeling error and logical error in a decision process. In this paper, the vehicle control for collision avoidance is studied with two control objectives, i.e., minimization of the safety distance error and regulation of the relative velocity between two vehicles. For this, a longitudinal controller using terminal sliding mode (TSM) with hierarchical structure is proposed for rear-end collision avoidance. The TSM is employed to achieve convergence in finite time, while the hierarchical approach is used for the system to accommodate the intelligence of the driver to handle various situations. The effectiveness of the proposed control scheme is verified by software simulations     

Data dissemination scheduling algorithm for V2R/V2V in multi-channel VANET

Considering that the data dissemination in multi-channel VANET (vehicular ad hoc network),a cooperative data dissemination scheduling algorithm was introduced for V2R(vehicle to roadside unit) and V2V(vehicle to vehicle).The algorithm created initial scheduling operators according to data requisition of vehicles.Then,initial collision graph and collision matrix were generated based on the conflict among initial scheduling operators.After proving the positive semidefinite of collision matrix,SDP (semidefinite programming) was used to channel allocation and collision graph creation.The algorithm then assigned weights for each data requisition according to dwell time and data volume of vehicles in RSU service region.Furthermore,it selected maximum weighted independent set of collision graph.The goal was to satisfy the most urgent data requisitions by V2R/V2V cooperate transmission.Transportation simulation results demonstrate that the proposed solution effectively promotes the service capacity by utilizes the multichannel of VANET and V2R/V2V transmission scheduling.     

LIDAR Sensing for Vehicle Lateral Guidance: Algorithm and Experimental Study

This paper describes a new vehicle detection system based on a laser imaging, detection, and ranging (LIDAR) sensor, and conducts an experimental study to investigate the sensor's role in the current California PATH vehicle lateral guidance systems. The LIDAR sensor is installed on a controlled vehicle and it can measure the relative distance of the vehicle from a preceding vehicle, by scanning the horizontal plane with laser beams. Environmental clutter becomes the main challenge in data processing, when LIDAR tries to track the desired target. A probabilistic data association-based algorithm has been developed to solve this problem, which has been verified in real-time experiments using two Buick LaSabre vehicles. The experimental study also reveals the relation between the LIDAR outputs and the magnetic reference system widely used by the current PATH lateral control systems, and the results provide the guidelines on how this new sensor system may be used for vehicle lateral guidance