基于简化路网模型的城市实时路况监控方法

在城市实时路况监控中, 因交叉路口延误时间的采集困难、计算模型复杂, 导致路况判别失准。针对该问题, 提出了一种基于简化路网模型的实时路况判别方法。该方法通过在道路通行数据采集时将各种类型的交叉口都抽象为一个节点, 并将在交叉口的延误时间计入相连道路的通行时间, 然后在监控时针对不同类型节点进行反推计算, 获得普通道路、环道以及立交桥的路况状态, 实现实时监控。最后通过对城市实时路况监控的仿真实验验证了方法的有效性。     

监控视频中的车辆异常行为检测

针对人工监测道路上车辆超速、违规变道和闯红灯等车辆异常行为各种弊端,提出了一种基于监控视频的车辆异常行为检测方法. 首先使用ViBe（Visual Background Extractor）算法得到车辆的前景图像,利用金字塔Lucas-Kanada光流法跟踪前景图像中的强角点并计算出该点的速度和角度,再利用均值漂移算法对速度和角度两个运动特征标量聚类,经统计得到聚类后的统计直方图. 最后,分别通过运动特征熵和运动特征标量到聚类中心的欧式距离2种方法判断车辆有无异常行为. 实验结果表明,2种方法能够准确、实时地检测出道路中的车辆异常行为.     

基于改进YOLOv5+DeepSort算法模型的交叉路口车辆实时检测

针对传统目标检测跟踪算法检测精度低、鲁棒性差的缺点，以及交叉路口图像视频资源冗余的现象和车辆密集程度高的特点，提出了一种基于改进YOLOv5和DeepSort算法模型的交叉路口实时车流量检测方法，在MS COCO和BDD100k相结合的数据集上，采用改进的YOLOv5算法模型实现视频小目标车辆检测，利用深度学习多目标跟踪算法DeepSort对检测的车辆进行实时跟踪计数，实现了交叉路口监控端对端的实时车流量检测。通过分析比较不同参数的模型，最终选定了YOLOv5m模型。实验结果表明，该方法在复杂环境、车辆遮挡和目标密集程度高等环境下检测速度更加快，对车辆的检测效果更好，平均准确度达到96.6%。该方法完全满足目标实时性检测的要求，能充分满足交叉路口车辆检测的有效性，满足实际需要的使用需求。     

背景估计与运动目标检测跟踪

基于视频的自动目标检测和跟踪是计算机视觉中一个重要的研究领域,特别是基于视频的智能车辆监控系统中的运动车辆的检测和跟踪。提出一种自适应的背景估计方法来实时获得当前背景图像,从而分割出运动物体。为了准确地定位运动车辆的区域,采用差分图像投影和边缘投影相结合的方法来定位车体,同时利用双向加权联合图匹配方法对运动车辆区域进行跟踪,即将对运动车辆区域跟踪问题转化为搜索具有最大权的联合图的问题。该算法不仅能实时地定位和跟踪直道上运动的车辆,同时也能实时地定位和跟踪弯道上运动的车辆,从实验结果看,提出的背景更新算法简单,并且运动车辆区域的定位具有很好的鲁棒性,从统计的检测率和运行时间来看,该算法具有很好的检测效果,同时也能满足基于视频的智能交通监控系统的需要。     

基于AT89C2051的交通车辆检测系统

针对目前道路交通信息采集的应用情况,介绍了一种基于单片机的环形线圈车辆检测器系统,并分析了系统的结构和功能.该系统的硬件主体以AT89C2051为控制核心,实现了路面动态交通数据的采集,采集到的数据实时反映了车辆的通过或存在状况.该系统结构简单,操作容易,能较精确地检测出车辆的存在,可应用于交通检测和道路监控领域.     

危险废物转移实时监控系统成本优化应用研究

研究了利用商业车载信息服务平台进行基于公众网的危险废物运输车辆实时监控,然后租用商业平台服务将GPS监控数据半实时交换入政务内网,供内网中的政务系统进一步利用的实时监控系统成本优化方法。该方法能同时实现上述车辆的实时监控及其政务管理功能,并能大幅度减少系统建设和运营成本。文章以广州市固体废物管理中心为实例对上述方法进行了计算、分析和讨论,并对方法的经济性、实用性、灵活性和安全性进行了总结。     

视频中运动目标的实时检测和跟踪

基于视频的自动目标检测和跟踪是计算机视觉中一个重要的研究领域，特别是基于视频的智能车辆监控系统中的运动车辆的检测和跟踪。提出了一种自适应的背景相减法来分割运动物体，为了准确地定位运动车辆的区域，采用差分图像投影和边缘投影相结合的方法来定位车体，同时利用双向加权联合图匹配方法对运动车辆区域进行跟踪，即将对运动车辆区域跟踪问题转化为搜索具有最大权的联合图的问题。该算法不仅能实时地定位和跟踪直道上运动的车辆，同时也能实时地定位和跟踪弯道上运动的车辆，从实验结果看，提出的背景更新算法简单，并且运动车辆区域的定位具有很好的鲁棒性，从统计的检测率和运行时间来看，该算法具有很好的检测效果，同时也能满足基于视频的智能交通监控系统的需要。     

基于改进动态阈值的运动车辆实时快速检测方法*

提出了复杂交通环境下一种新的运动车辆检测方法。基于背景差分获得运动图像,利用自适应阈值选取方法分别对差分图像的三个颜色通道进行二值化,从而实现运动目标的精确检测。根据检测结果,采用中值更新方法实现背景图像的实时更新。实验结果表明,这种基于改进动态阈值和自适应背景相结合的快速检测算法可以从复杂交通场景图像序列中快速有效地检测出运动目标,能够很好地满足智能交通监控系统中运动车辆实时检测的要求。     

基于AT89C51的实时交通监控系统的研究与模拟

实时交通监控系统采用AT89C51为控制器,通过对各路口来往车辆的流量和速度的实时检测,并根据检测的结果动态、实时地控制当前交通灯时间,使LED显示器进行倒计时工作并与状态灯保持同步,可在保证交通安全的前提下最大限度地提高交通效率,而且允许处理紧急情况的发生。经仿真模拟的试验,该系统得到了预期的实时控制效果。本论文针对道路交通拥挤、交叉路口经常出现拥堵的情况,利用单片机控制技术,从硬件设计和软件设计两个方面分别介绍通用小型实时交通监控系统的设计方法。     

复杂动态环境下运动车辆的识别方法

针对目前车辆识别方法在动态变化的复杂环境中车辆识别正确率低的问题,提出了一种基于动态自适应阈值的车辆识别方法。该方法首先利用基于熵权法的图像质量量化算法计算交通流视频中背景图像的质量值;然后通过对样本交通流设置的车辆检测阈值和基于该阈值识别车辆的正确率进行多项式拟合,获得该样本的车辆最佳检测阈值;最后对样本背景图像的质量值和样本车辆的最佳检测阈值进行高斯拟合,得到自适应阈值计算模型。该方法采用高斯混合模型实时获取交通流视频中的背景图像,计算背景图像的质量值,并输入到自适应阈值计算模型得到实时的车辆最佳检测阈值以识别车辆。实验和理论分析表明,该方法能根据动态变化的环境实时更新车辆检测阈值,有效地提高了车辆识别的正确率。     

基于PCA-SVM准则改进区域生长的非结构化道路识别

针对智能车辆在非结构化道路识别中需要采用众多的特征参数,增加了特征融合识别难度与计算复杂度,并且部分背景与道路区域存在相似性会产生道路识别的误分、误判的问题,提出了一种基于主成分分析的支持向量机（PCA-SVM）准则改进区域生长的非结构化道路识别算法。首先,对非结构化道路颜色、纹理等复杂特征信息进行提取,采用PCA对提取的特征信息进行降维;然后,利用降维后的主元特征对SVM进行训练后作为复杂道路单元格的分类器。利用道路位置、起始单元格等先验知识以及道路边界单元格统计特征改进区域生长方法,在单元格生长时利用分类器判别,排除误判区域。实际道路检测结果表明,所提算法具有较好的鲁棒性,能够有效识别非结构化路面区域。对比结果表明,所提算法在保证准确率的同时,将10余维复杂特征信息压缩为3维主元特征,相比传统算法可缩短计算时间一半以上。针对背景与道路相似区域造成的传统算法10%左右的误判问题,所提算法能够有效排除。在野外环境下基于视觉的局部路径规划与导航方面,所提算法为缩短识别时间、排除背景干扰提供了可行途径。     

Road detection algorithm for Autonomous Navigation Systems based on dark channel prior and vanishing point in complex road scenes

Vision-based road extraction is essentially important in many fields, such as for intelligent traffic and robot navigation. However, the road detection in urban or ill-structured roads is still very challenging at current stage, and the existing methods often suffer from high computational complexity. This paper reports a novel and efficient method for road detection in challenging scenes. First, the dark channel based image segmentation is proposed to distinguish a rough road region from complex background noise, which is envisioned to reduce the workload of road detection. Furthermore, instead of using the conventional pixel-wise soft voting, a new voting strategy based on the vanishing point and the properties of the segmented regions is proposed to further reduce the computation time of road extraction stage. Finally, the segmented region which has the maximum voting value is selected as the road region. Experimental results demonstrated that the proposed algorithm shows superior performance in different kinds of road scenes. It can remove the interference from pedestrians, vehicles and other obstacles. Our method is about 40 times faster in detection speed, when compared to a recently well-known approach.     

A cell-based robust optimal coordinated control on urban arterial road

Process of optimizing coordinated control is divided into two stages.At the first stage,the study improves a robust optimal control model of single-point intersection to optimize cycle and split.At the second stage,the study combines all links with intersections of arterial road as a complete system,and applies cell transmission model to simulate traffic flow on urban signalized arterial road.We propose a coordinated control model based on the platform to optimize offset between adjacent intersections.Genetic algorithm is executed by MATLAB to solve the model.The performance evaluations show that the model not only effectively reduces average delay and stopping rate of vehicles on arterial road and largely enhances traffic capacity of arterial road,but also lowers the sensitivity of signal control for flow fluctuations.     

Detailed traffic animation for urban road networks

We present a new agent-based system for detailed traffic animation on urban arterial networks with diverse junctions like signalized crossing, merging and weaving areas. To control the motion of traffic for visualization and animation purposes, we utilize the popular follow-the-leader method to simulate various vehicle types and intelligent driving styles. We also introduce a continuous lane-changing model to imitate the vehicle’s decision-making process and dynamic interactions with neighboring vehicles. By applying our approach in several typical urban traffic scenarios, we demonstrate that our system can well visualize vehicles’ behaviors in a realistic manner on complex road networks and generate immersive traffic flow animations with smooth accelerating strategies and flexible lane changes.     

基于概率算法自适应更新背景的运动车辆检测

交通流量检测是智能交通系统中的一个重要研究方向和热点问题,基于视频的车辆检测是交通流量采集分析的核心技术,它为交通流量参数的实时获取提供了可能。为实现在复杂交通视频场景中实时准确检测各类的运动车辆,在研究传统背景差分算法的缺点的工作基础上,提出一个自适应的贝叶斯概率背景检测算法,进而完成了较准确的运动车辆分类检测。实验结果表明该方法具有高效实时的特点,能够较准确地实现复杂交通路面的背景提取和运动车辆的检测,具有良好的鲁棒性。     

A roadside simulation of road crossing for children

A simple and safe method is proposed for giving children practical experience similar to crossing the road and for assessing their performance. The method comprises a ‘pretend road’ laid out on the pavement, which the child crosses as if crossing the adjacent road in the face of oncoming vehicles. A comparison of adult performances in crossing through gaps in traffic on pretend and real roads indicates that the pretend task adequately simulates real road crossing. Similar experiments on pretend roads with 5-10 year olds crossing through gaps in traffic indicated that children are able to understand the simulation task and perform sensibly on it. Moreover, there were children of all ages who consistently performed at close to an adult level indicating that the visual timing required in the skill is not beyond young children. The results suggest that children should be trained in crossing in the presence of traffic at an early age. The pretend task could prove a valuable aid to training.     

Road scene analysis for determination of road traffic density

Road traffic density has always been a concern in large cities around the world, and many approaches were developed to assist in solving congestions related to slow traffic flow. This work proposes a congestion rate estimation approach that relies on real-time video scenes of road traffic, and was implemented and evaluated on eight different hotspots covering 33 different urban roads. The approach relies on road scene morphology for estimation of vehicles average speed along with measuring the overall video scenes randomness acting as a frame texture analysis indicator. Experimental results shows the feasibility of the proposed approach in reliably estimating traffic density and in providing an early warning to drivers on road conditions, thereby mitigating the negative effect of slow traffic flow on their daily lives.     

一种基于分层道路网的数据准备模型及实现

为了缩短计算中心与车辆之间的数据传送时间，提出并实现了一种TMSCR数据准备模型，即在包含起止点的一个网格集合的外接矩形区域中，提取起点网格内的低层路段、终点网格内的低层路段和所有高层路段的并集，发送给车辆。实验表明，实现该模型的时间代价很小，TMSCR模型与传统的方法相比，可以大大节省通信时间，从而为车辆导航提供优质的服务。     

对光照鲁棒的道路边缘检测算法

针对在光照变化和强阴影干扰条件下的道路边缘检测问题,提出了一种对光照鲁棒的道路边缘检测算法。该算法结合导向滤波和抗阴影特征提取器,首先,采用导向滤波对图像的边缘进行增强,减少背景噪声干扰;其次,利用抗阴影道路特征提取器提取道路粗边缘轮廓;最后,采用模糊连通性分析,结合道路边缘全局信息将道路边缘分为远、近两部分,对提取的边缘点进行修正,并采用RANSAC进行拟合。实验部分采用ROMA数据集对算法进行验证,实验结果表明,该边缘检测算法的综合性能指标为83.67%,在各种道路条件下,具有较好的鲁棒性和准确性。     

Real-time vehicle tracking mechanism with license plate recognition from road images

Abstract Information about vehicles on the road is very important for the maintenance of traffic control in current complex traffic condition. Images of vehicles are captured by vehicle-directed cameras. This paper proposes a new vehicle tracking mechanism using license plate recognition technology, which is essential to having information about vehicles on the roads. The proposed method is a real-time processing system using multistep image processing, as well as recognition and tracking processes from 2D and 3D images. The experimental results of real environmental images in recognition and tracking using the proposed method are shown.