无线网络导航服务系统的设计与实现

近几年,LBS 位置服务业务已成为热点.据此,提出一种基于无线网络的导航服务(Wireless-based Navigation Services)系统并给出了系统结构设计和各部分功能实现方法.该系统可为智能手机或 PDA 用户路径规划、地图查询和实时定位等导航服务.     

GETA sandals: a footstep location tracking system

This paper presents the design, implementation, and evaluation of a footstep based indoor location system. The traditional Japanese GETA sandals are equipped with force, ultrasonic, orientation, RFID sensors and an accelerometer to produce a wearable location tracking system that demand little infrastructure in the deployed environment. In its basic form, a user simply puts on GETA sandals to enable tracking of his/her locations relative to a starting point (e.g., a building entrance), making it easy for deployment everywhere. The footstep location system is based on dead-reckoning, which works by measuring and tracking displacement vectors along a trail of footsteps. Each displacement vector is formed by drawing a line between each pair of footsteps, and the position of a user can be calculated by summing up the current and all previous displacement vectors. Unlike most existing indoor location systems, the footstep based method does not suffer from problems with obstacles, multi-path effects, signal noises, signal interferences, and dead spots. There are two technical challenges in the proposed design: (1) location error accumulates over distance traveled, and (2) displacement measurements are sporadic during stair climbing. The first problem is addressed by a light RFID infrastructure, while the second problem is remedied by incorporating an accelerometer into the system. Experiments on GETA prototype are conducted to evaluate the positional accuracy of our system.     

Landmark-assisted location and tracking in outdoor mobile network

Modern mobile devices integrating sensors, like accelerometers and cameras, are paving the way to the definition of high-quality and accurate geolocation solutions based on the informations acquired by these sensors, and data collected and managed by GSM/3G networks. In this paper, we present a technique that provides geolocation and mobility prediction of mobile devices, mixing the location information acquired with the GSM/3G infrastructure and the results of a landmark matching achieved thanks to the camera integrated on the mobile devices. Our geolocation approach is based on an advanced Time-Forwarding algorithm and on database correlation technique over Received Signal Strength Indication (RSSI) data, and integrates information produced by a landmark recognition infrastructure, to enhance algorithm performances in those areas with poor signal and low accurate geolocation. Performances of the algorithm are evaluated on real data from a complex urban environment.     

二元传感器网络目标定位与跟踪研究

传感器的通信带宽和能量资源有限使传统的位置测量传感器的应用受到了限制,对此,选择利用二元传感器网络进行相应的研究．基于二元传感器传送信息量少的特性,提出一种新的二元传感器网络目标定位与跟踪算法．仿真结果表明,该算法在传感器个数和探测半径较大、采样周期较短的情况下较质心算法具有更好的性能．     

基于UKF-RSS在线建模的WSN节点跟踪定位算法

在传感器网络中（WSN）锚节点负责接收GPS定位信号,但其使用寿命受能量约束,为了提高传感器网络的生存周期和定位精度,提出基于无迹Calman滤波（UKF）和传感器网络锚节点RSS在线建模的WSN定位算法,实现高效资源管理和利用方式。该算法主要包括位置预测和目标定位两个步骤,利用UKF算法对目标节点的下一位置进行预测,选择开启距离预测位置最近的几个锚节点,关闭无用锚节点,有效降低网络能耗。利用锚节点之间相互信号强弱基于RSS对开启锚节点周围的距离与RSS信号强弱关系进行建模,降低RSS算法对环境的依赖度。实验结果表明该算法能够有效对锚节点的开启/睡眠进行管理,并可降低环境依赖性,从而实现负载均衡降低能耗和提高定位精度的效果。     

基于Mega2560的人脸检测与定位跟踪

为了解决存在外界干扰的人脸的检测和准确定位与跟踪问题,避免过于依赖软技术造成的算法复杂性,采用软硬件结合的方式,基于Mega2560单片机、VS2008开发环境与OpenCV函数库,实现了人脸检测与准确定位与跟踪。首先,利用Haar-like特征法寻找出图像中的人脸特征矩形,通过AdaBoost算法生成级联分类器,实现人脸检测;然后,将图像显示窗口中心选为坐标原点,计算人脸位置,用线性变换的方法获取人脸位置偏差,进而转换成角度偏差发送给下位机Mega2560;最后,单片机根据接收到的角度偏差信息,控制摄像头使人脸始终在坐标原点位置,实现人脸的准确定位与跟踪。通过实验表明系统具有较好的稳定性和准确性。     

Robust location tracking using a dual layer particle filter

Location awareness is an important part of many ubiquitous computing systems, but a perfect location system does not exist yet. Among many location tracking systems, we choose the radio frequency identification (RFID) system due to its various applications. However, the received signal strength indicator (RSSI) signals are too sensitive to the direction of the RFID reader’s antenna, the orientation of the RFID tag, human interference, and the diversity of propagation media that might be present. As a result, the direct use of a conventional particle filter does not provide satisfactory tracking performance. To overcome this problem, we suggest a dual layer particle filter, where the lower layer determines the tag’s location in the block level using a triangulation technique or the support vector machine (SVM) classifier, and the upper layer accurately estimates the tag’s location using the conventional particle filter within the pre-computed or classified block. This layered structure improves the location estimation and the tracking performance, because the location evidence from the lower layer effectively restricts the range of possible locations of the upper layer. We implement the proposed location tracking method using a ubiquitous RFID wireless network in an intelligent office, where several RFID readers are located in fixed locations and people or objects with active RFID tags move around the office. Extensive experiments show that the proposed location tracking method is so precise and robust that it is a good choice for person or object tracking in ubiquitous computing contexts. We also validate the usefulness of the proposed location tracking method by implementing it for a real-time people monitoring system in a noisy and complex steel mill.     

非视距传播环境下的AOA定位跟踪算法

基于几何结构的单次反射统计信道模型,提出了一种在非视距(NLOS)传播环境下对移动台的到达角(AOA)的定位与跟踪算法.首先利用径向基函数(RBF)神经网络对NLOS误差进行修正,再利用最小二乘(LS)算法进行移动台位置估计,然后配合相关检测距离门对移动台进行跟踪.仿真结果表明,该跟踪算法能够有效地实现移动台的静态定位...     

Global radionavigation and location systems for tracking marine mammals

Over the past decade the Argos System has become a widely used tool for animal tracking. This paper investigates whether lower costs and energy requirements could be achieved by alternative techniques. These include the global radionavigation systems GPS and Omega which employ low-powered receivers rather than the high-powered transmitters of Argos. A variety of systems are studied and their costs and energy requirements modelled within specific marine mammal tracking scenarios. This paper presents a fundamental analysis exploring current and future options available to researchers who need to track marine mammals.     

基于RSSI的高精度实时室内人员跟踪定位的改进

在能量有限的网络节点中,利用RSSI测距只需较少的通信开销和较低的实现复杂度.实际应用环境中,由于受不同的传播方向和传播介质的影响,在定位过程中产生的距离误差比较大.在此算法的基础上结合平滑算法,提出了增强型RSSI算法.增强型RSSI算法是将前一个 RSSI的值大小与当前的做一个平滑动作,主要降低移动目标的动能波动,从而对室内的人员进行更加精确的跟踪定位,通过与简单的RSSI进行比较,仿真验证了平滑算法的定位的精确性与有效性.     

基于DSP的说话人定位跟踪系统的设计

针对室内说话人实时定位跟踪不准确的问题,提出了一种基于TMS320DM6437硬件平台的音视频融合定位跟踪方法。该方法利用Kalman滤波器和Mean-shift算法搜寻说话人最优位置进行视频定位跟踪。同时,采用到达时间差的音频方法进行目标位置估计。由Kalman信息整合中心进行音视频融合,以提高视听系统定位跟踪的稳定性。实验结果表明,与单模态定位跟踪系统相比,该方法对320×240的图像可实现平均20frame/s的跟踪速度,能提高目标定位跟踪准确度17%,改进效果明显且稳定。     

Emitter location using an angle-only tracking filter with own-ship trajectory estimation

An angle-only tracking algorithm to locate the emitter source position from an overflight vehicle is presented. The algorithm uses an extended Kalman filter with angular data from an onboard direction finder. The dynamic relationship between the emitter and own-ship motion is formulated in modified polar coordinates (MPC), which yields good noise-handling performance. The MPC filter method, however, encounters slow convergence problem under realistic overflight scenarios, where the lateral sightline motion inputs are mild. By using the knowledge on an own-ship estimator and computed pseudo-measurements for range and range-rate over range, the convergence of estimator is greatly accelerated. The combined scheme of this trajectory estimation filter and the MPC filter markedly improves the tracking accuracy as well. Simulation results reveal that the proposed algorithm is superior to that of the MPC filter algorithm.     

MoteTrack: a robust, decentralized approach to RF-based location tracking

In this paper, we present a robust, decentralized approach to RF-based location tracking. Our system, called MoteTrack, is based on low-power radio transceivers coupled with a modest amount of computation and storage capabilities. MoteTrack does not rely upon any back-end server or network infrastructure: the location of each mobile node is computed using a received radio signal strength signature from numerous beacon nodes to a database of signatures that is replicated across the beacon nodes themselves. This design allows the system to function despite significant failures of the radio beacon infrastructure. In our deployment of MoteTrack, consisting of 23 beacon nodes distributed across our Computer Science building, we achieve a 50th percentile and 80th percentile location-tracking accuracy of 0.9 and 1.6 m respectively. In addition, MoteTrack can tolerate the failure of up to 60% of the beacon nodes without severely degrading accuracy, making the system suitable for deployment in highly volatile conditions. We present a detailed analysis of MoteTrack’s performance under a wide range of conditions, including variance in the number of obstructions, beacon node failure, radio signature perturbations, receiver sensitivity, and beacon node density.     

基于多尺度的EKF滤波融合定位跟踪算法

针对无线定位中快速移动目标的定位精度差的问题,提出了一种简单有效的定位跟踪算法。该算法将信号的多尺度分析方法与基于TDOA的蜂窝网定位技术相结合,基于某尺度上获得的单一的观测量,建立了一个新的多尺度的观测模型。基于新的多尺度观测模型,利用扩展Kalman滤波对目标进行定位跟踪,获得比在原始尺度上直接进行滤波定位跟踪更好的效果。通过仿真验证了该方法对提高蜂窝网无线定位精度的有效性。     

基于谷歌地球和GPS的物品定位跟踪系统

介绍了基于Google Earth和GPS进行目标物品定位跟踪系统开发的研究背景,借助相关技术进行了目标物品定位跟踪系统的总体构架设计以及功能设计,并选择基于C#语言、ASP.NET技术以及Microsoft Visual Studio 2005开发工具实现了编码开发。进行了实测轨迹实时定位跟踪实验,实验结果表明,基于Google Earth和GPS的目标物品定位跟踪系统能准确的实时定位、跟踪目标物品,达到了预期目的。提出的Google Earth和GPS技术相结合的开发思路,为地图位置服务提供了方法依据。     

公共区域监控视频数据目标特征跟踪定位方法

为了提高公共区域监控视频的目标定位检测能力,需要进行目标特征跟踪定位算法设计,提出一种基于图像超分辨率重建的公共区域监控视频数据目标特征跟踪定位方法。构建公共区域监控视频的三维图像重建模型,采用边缘层的高分辨融合方法进行公共区域监控视频图像数据的三维结构重组,提取公共区域监控视频的关键特征点,用图像退化模型进行公共区域监控视频数据目标特征检测,结合线性滤波模型使得监测输出图像满足最优匹配特征解,提高对公共区域监控视频数据目标特征跟踪能力。引入引导滤波方法进行公共区域监控视频数据的图像超分辨重建,实现对目标特征准确跟踪定位。仿真结果表明,采用该方法进行公共区域监控视频数据目标特征跟踪定位的准确性较高,图像重建能力较强,归一化均方根误差较小。     

Particle filter algorithm based spatial motion tracking of football landing location

In order to improve the accuracy of the tracking of football landing location, a football landing location and spatial motion tracking system based on APRBA multi-camera was proposed. First of all, the study of football movement locus model was conducted. Without considering the speed limit and direction restriction, Bayesian state evolution model was constructed, and based on path loss model, the moving target positioning observation model was established. Secondly, by using the ultrasonic food source localization of the proposed APRBA algorithm and the next target prediction, the particle filter algorithm was improved to realize the effective improvement of target tracking accuracy. Finally, the effectiveness of the proposed target tracking algorithm was verified in the tracking experiment of the moving target model.

     

基于外辐射源的单站无源定位跟踪算法

基于外辐射源的无源定位系统是以电视或调频广播的发射机等作为其辐射源的,具有反侦察、抗干扰,反隐身、抗反辐射导弹等优势.根据基于外辐射源进行定位的特点,提出了一种在利用常用观测量方位角、俯仰角及时差信息的基础上,增加角度变化率信息的单站无源定位与跟踪方法.计算机仿真结果表明,该定位方法具有较好的定位精度和定位速度,具有很大的实用价值.     

An indoor location tracking based on mobile RFID for smart exhibition service

Recently, various smart application services have been developed using GPS (Global Positioning System), RFID (Radio Frequency IDentification) and sensor networks. The GPS has been successfully applied for outdoor location tracking by many applications, but it might still be insufficient in an indoor environment where GPS signals are often severely obstructed. The RFID technology has been utilized to play an important role in location tracking for indoor smart applications. Therefore, in this paper, we present the scenario and architecture of an indoor location tracking service for things or space in an exhibition environment based on mobile RFID. The RFID tags of things or spaces are identified as the locations of point being passed and we obtain the spatial data from the tags using mobile RFID readers, Web server and Database server. We have designed and implemented the prototype of location tracking system for exhibition scenario using Microsoft .NET framework. Additionally, we have verified the functionality of this system so various other indoor smart services may be provided using the proposed system.     

一种基于预测的实时人脸特征点定位跟踪算法

当前的人脸特征点定位跟踪方法因其计算量大,实时特性欠佳。给出了一种基于改进Viola-Jones算法和Kalman滤波器预测机制的定位及跟踪算法。该算法通过使用改进的Viola-Jones算法对本次人脸特征点进行定位,同时使用Kalman滤波算法对特征点下次出现位置进行预测,缩小了下一帧特征点定位过程中特征点的搜索范围,因而缩短了定位搜索时间。实验结果表明该方法在保证定位准确性和鲁棒性的同时明显增强了算法的实时性。