基于车载视频监控的乘客检测及跟踪算法

针对公交车上乘客相互遮挡及光照变化明显的问题,提出一种基于头肩部边缘特征和局部不变特征的人体检测及跟踪算法。首先对待检测图像进行自适应阈值背景差分,实现乘客目标分割;然后用样本的梯度方向直方图(HOG)特征训练支持向量机(SVM)基础分类器,结合自适应增强(AdaBoost)算法提炼出最终的强分类器,对前景图像进行扫描实现乘客目标检测;最后提取目标区域和当前搜索区域的快速鲁棒性特征(SURF),通过特征点匹配实现乘客目标跟踪。实验表明,在乘客相互遮挡及光照变化明显的情况下,该算法仍具有高于80%的检测率和跟踪率,且满足系统实时性的要求,可用于客流计数。     

一种结合多特征的前方车辆检测与跟踪方法

车辆检测是汽车防碰撞预警的前提,为了提高前方车辆检测的实时性和鲁棒性,提出一种结合多特征的前方车辆检测跟踪方法。该方法不依赖车道检测,利用车底部阴影的梯度特征确定可能存在车辆的区域,使用差分盒子维计算对应区域的分形维数来排除噪声,根据车辆的水平边缘特征信息精确定位,通过卡尔曼滤波器跟踪检测到的目标,利用归一化转动惯量做车辆验证。实验结果表明,该方法能够在多种交通环境中实时有效地检测前方车辆。     

基于TLD改进的自动人体检测与实时跟踪算法

首先提出一种运动人体检测算法,通过图像序列识别出运动人体作为跟踪目标,然后在TLD算法中引入目标轨迹预测,利用该信息来辅助空间搜索。运动人体检测算法首先采用背景减除和边缘检测算法获得完整目标轮廓,然后使用HU仿射不变矩检测出运动人体,该特征能适应目标旋转、尺度、仿射等变化场合。为提高跟踪实时性,在TLD框架中引入卡尔曼轨迹预测,并先在预测位置邻域搜索。实验结果表明,该运动人体检测算法能够在静态和动态背景下准确地检测出运动人体;改进后的TLD算法与原始算法相比,在准确率不降低情况下,降低了计算复杂度。     

基于半监督自动谱聚类算法的网络故障检测

针对网络故障检测中利用先验知识不足和多数谱聚类算法需事先确定聚类数的问题,提出一种新的基于成对约束信息传播与自动确定聚类数相结合的半监督自动谱聚类算法。通过学习一种新的相似性测度函数来满足约束条件,改进NJW聚类算法,对非规范化的Laplacian矩阵特征向量进行自动谱聚类,从而提高聚类性能。在UCI标准数据集和网络实测数据上的实验表明,该算法较相关比对算法聚类准确率更高,可满足网络故障检测的实际需要。     

考虑侧倾的无人车NMPC轨迹跟踪控制

针对高速行驶工况下,无人车转弯时的侧倾易导致车辆模型非线性程度增加,引起轨迹跟踪精度下降和状态失稳的问题,设计一种考虑车辆侧倾因素,基于非线性模型预测控制(NMPC)的无人车轨迹跟踪控制器.根据拉格朗日分析力学和车辆运动学,考虑车辆侧倾几何学和载荷转移效应,建立考虑侧倾因素的非线性车辆模型,包括车体动力学模型和修正的“Magic Formula”轮胎模型;基于此车辆模型,构建非线性模型预测控制器(NMPC)的预测模型,并设定控制器的线性、非线性约束,以保证车辆的运动状态处于稳定区域内.在Carsim和Simulink联合仿真平台上,验证车辆高速蛇形工况和双移线工况下的轨迹跟踪控制效果,仿真结果显示,所设计的控制器可有效改善高速弯道工况下的跟踪精度和车辆状态稳定性.     

基于轨迹的足球检测与跟踪

在足球比赛视频中对足球进行检测和跟踪,如果球与球场线融合或球与球员形成连通区域,则得到球的位置信息将变得非常困难.针对这类问题提出了一种基于轨迹的解决方案.基于维特比算法检测并跟踪球,应用最小二乘法得到球运动轨迹的插值函数,基于所得到的插值函数,剔除维特比算法检测与跟踪球过程中的一些误检,同时补充漏检处的球位置信息.通过实验验证,算法具有较高的准确性.     

二进制无线传感器网络目标定位跟踪算法

二进制无线传感器网络是一种新的和具有巨大潜在应用前景的目标定位跟踪平台,它具有通信负荷少,生存能力强等特点。提出一种基于网络时间的迭代算法,在目标通过一定数量的节点后,给出较为精确的目标运动参数,并在算法迭代的过程中,不断优化算法结果。最后,运用多Agent仿真思想,借助于RePAST仿真平台对算法进行了仿真验证。     

Real-time multiple vehicle detection and tracking from a moving vehicle

Abstract. A real-time vision system has been developed that analyzes color videos taken from a forward-looking video camera in a car driving on a highway. The system uses a combination of color, edge, and motion information to recognize and track the road boundaries, lane markings and other vehicles on the road. Cars are recognized by matching templates that are cropped from the input data online and by detecting highway scene features and evaluating how they relate to each other. Cars are also detected by temporal differencing and by tracking motion parameters that are typical for cars. The system recognizes and tracks road boundaries and lane markings using a recursive least-squares filter. Experimental results demonstrate robust, real-time car detection and tracking over thousands of image frames. The data includes video taken under difficult visibility conditions. Received: 1 September 1998 / Accepted: 22 February 2000     

Fuzzy-genetic algorithm for automatic fault detection in HVAC systems

Detecting fault before it deteriorates the system performance is crucial for the reliability and safety of many engineering systems. This paper develops an intelligent technique based on fuzzy-genetic algorithm (FGA) for automatically detecting faults on HVAC system. Many researchers have proposed only using fuzzy systems to effect fault detection and diagnosis. Other applications of the FGA are mainly focused on the synthesis of fuzzy control rules. The proposed automatic fault detection system (AFD) monitors the HVAC system states continuously by fuzzy system. The optimization capability of genetic algorithms allows the generation of optimal fuzzy rules. Faults are represented as different fault levels in the AFD system and are distinguished by fuzzy system after tuning its rule table. Simulation studies are conducted to verify the proposed AFD system for the single zone air handler system.     

基于卡尔曼滤波器的抗遮挡车辆跟踪算法

针对由于车辆相互遮挡而不能准确跟踪车辆的问题,提出一种基于卡尔曼滤波器的跟踪算法。算法利用基于图像内容敏感度的背景提取算法,获取目标车辆的二值化图像,然后采用卡尔曼滤波器预测目标车辆在下一帧中的状态,在预测区域中进行搜索匹配,建立相邻帧中目标车辆的对应关系,有效推理目标车辆的驶入、驶出以及遮挡和分离,并根据预测信息对发生遮挡的目标进行跟踪。实验结果表明,该算法能够获得良好的跟踪效果。     

Path tracking controller design of four wheel independent steering automatic guided vehicle

This paper presents a new type of four wheel independent steering automatic guided vehicle (4WIS-AGV) for carrying heavy baggage and proposes a controller for the 4WIS-AGV to track reference trajectories. To do this task, the followings are done. Firstly, a 4WIS-AGV is designed and manufactured for experimental purpose. Secondly, a kinematic modeling for the 4WIS-AGV is introduced based on a single track vehicle model. Thirdly, based on the modeling, a controller is designed based on Backstepping method for the 4WIS-AGV to track reference trajectories. Fourthly, a control system is developed using industrial PC and AVR ATmega128 microcontrollers to implement the designed controller. Finally, simulations and experiments are conducted to verify the effectiveness and performances of the proposed controller in tracking two types of reference trajectories: a trajectory with sharp edges for parallel steering maneuver and a circular trajectory for zero-sideslip maneuver. The results show that the proposed controller can make the 4WIS-AGV track the trajectory with sharp edges and the circular trajectory very well.     

基于UWB的智能跟随车导航定位算法研究

针对目前市场上现有智能跟随车定位精度不足,提出一种基于UWB信号的定位算法。在智能跟随车的上方安置两个固定基站,手持标签到两个基站的距离数据经过卡尔曼滤波算法的处理,利用三角函数进行计算,得出标签到两个基站中点的距离和偏移角度,将距离和角度数据传送给电机控制模块,通过PID控制算法调节PWM值,从而控制电机的转速和转向。实验表明,该方法能够实现标签定位的距离误差小于9 cm,角度误差小于10°,使智能跟随车的定位更为精准。     

基于AUPF的TDOA几何定位跟踪算法研究

使用无源时差（TDOA）定位技术确定无人机等小型辐射源目标的位置是当前研究的热点,针对时差定位算法较为复杂的实际情况,推导了时差双曲线的几何解,并提出了一种基于自适应无迹粒子滤波（AUPF）技术的移动目标定位跟踪方法。通过仿真对该方法在不同场景的应用效果进行了验证,进一步比较分析了算法的定位精度。结果表明,基于自适应无迹粒子滤波的时差几何定位跟踪算法可以在多种情况下较好地拟合出目标真实运动轨迹,实现对运动目标的定位跟踪,同时拥有更低的定位误差和更高的轨迹包容度,使用该方法可以显著提高对非合作移动辐射源目标的位置估计性能。     

Model based vehicle detection and tracking for autonomous urban driving

Situational awareness is crucial for autonomous driving in urban environments. This paper describes the moving vehicle detection and tracking module that we developed for our autonomous driving robot Junior. The robot won second place in the Urban Grand Challenge, an autonomous driving race organized by the U.S. Government in 2007. The module provides reliable detection and tracking of moving vehicles from a high-speed moving platform using laser range finders. Our approach models both dynamic and geometric properties of the tracked vehicles and estimates them using a single Bayes filter per vehicle. We present the notion of motion evidence, which allows us to overcome the low signal-to-noise ratio that arises during rapid detection of moving vehicles in noisy urban environments. Furthermore, we show how to build consistent and efficient 2D representations out of 3D range data and how to detect poorly visible black vehicles. Experimental validation includes the most challenging conditions presented at the Urban Grand Challenge as well as other urban settings.     

Visual vehicle detection and tracking based on the 'sign pattern'

Real-time vehicle detection and tracking applicable for outdoor mobile robots on a structured road is proposed. The method is based on a locomotion strategy known as 'sign pattern based stereotyped motion'. The sign pattern of a vehicle is the shadow underneath. The robot detects a vehicle from a distance of 30 m with a domestic video camera and extracts its front shape in real-time processing. The distance between the robot and vehicle, and the velocity and width of the vehicle are estimated during the tracking process. In addition, the center of the vehicle in two-dimensional imaging is determined during the tracking process to estimate the type of motion. The accuracy rate of vehicle width measurement based on the shadow underneath is better than 90% in practice, which can be adequately used for vehicle avoidance applications. The applied method has been tested on roads covered with different types of shadows as well as under different weather conditions. The results of the experiments verify the validity of the method.     

基于视频的高速公路车辆检测和跟踪算法

采用一种基于像素的新方法来更新背景，同时将工作区域分为车辆检测和车辆跟踪两个部分，在车辆检测区建立跟踪对象，在车辆跟踪区仅仅对跟踪对象进行预测跟踪，从而减少了跟踪的盲目性和算法的计算量，提高算法精度。根据该算法设计的视频检测器已用于实际交通参数的采集，统计的结果表明该算法检测和跟踪的正确率分别高于96%和97%，并具有很好的实时性，能满足管理部门的需求。     

基于多信息综合的运动车辆跟踪算法

综合车辆本身的区域和特征信息,提出了一种在交通场景中跟踪运动车辆的新方法。该方法主要解决运动目标在遮挡、粘连以及分裂情况下的跟踪问题。首先通过引入的预测机制建立序列图像间运动区域的关联,并根据区域关联的结果判断是否出现以上情况。针对车辆遮挡和粘连的问题,采用基于特征点跟踪的方法解决,先根据车辆区域信息对特征点进行初始化,然后在图像中预测位置的邻域内搜索匹配点从而实现特征点的跟踪和聚类。对于车辆分裂的情况,根据提出的规则对判定的区域进行融合后进行模板匹配从而解决分裂的问题。实验结果表明该方法具有较强的鲁棒性和较好的实时性。     

一种波形相似度的车辆检测融合算法

利用磁阻传感器可以实现停车位的车辆{有,无}状态检测,但是磁信号容易受到相邻车位停车干扰而导致误检,针对该问题设计了一种数据融合算法,将车辆磁信号建模为分段线性时间序列,提出了形态距离公式度量时间序列的相似度,计算相邻车位传感器磁信号的波形相似度实现车辆检测,在路面停车区域实地部署了50个磁阻传感器节点,通过长达5个多月的实验,结果表明该算法提高了车辆检测准确率.