MagneFi: Multiuser, Multi-Building and Multi-Floor Geomagnetic Field Dataset for Indoor Positioning

Indoor positioning and localization have emerged as a potential research area during the last few years owing to the wide proliferation of smartphones and the inception of location-attached services for the consumer industry.Due to the importance of precise location information,several positioning technologies are adopted such as Wi-Fi,ultrawideband,infrared,radio frequency identification,Bluetooth beacons,pedestrian dead reckoning,and magnetic field,etc.Although Wi-Fi and magnetic field-based positioning are more attractive concerning the deployment of Wi-Fi access points and ubiquity of magnetic field data,the latter is preferred as it does not require any additional infrastructure as other approaches do.Despite the advantages of magnetic field positioning,comparing the performance of positioning and localization algorithms is very difficult due to the lack of good public datasets that cover various aspects of the magnetic field data.Available datasets do not provide the data to analyze the impact of device heterogeneity,user heights,and time-specific magnetic field mutation.Moreover,multi-floor and multibuilding data are available for the evaluation of state-of-the-art approaches.To overcome the above-mentioned issues,this study presents multi-user,multidevice,multi-building magnetic field data which is collected over a longer period.The dataset contains the data from five different smartphones including Samsung Galaxy S8,S9,A8,LG G6,and LG G7 for three geographically separated buildings.Three users including one female and two males collected the data for various path geometry and data collection scenarios.Moreover,the data contains the magnetic field samples collected on stairs to test multifloor localization.Besides the magnetic field data,the data from inertial measurement unit sensors like the accelerometer,motion sensors,and barometer is provided as well.

Wi-Fi Positioning Dataset with Multiusers and Multidevices Considering Spatio-Temporal Variations

Precise information on indoor positioning provides a foundation for position-related customer services.Despite the emergence of several indoor positioning technologies such as ultrawideband,infrared,radio frequency identification,Bluetooth beacons,pedestrian dead reckoning,and magnetic field,Wi-Fi is one of the most widely used technologies.Predominantly,Wi-Fi fingerprinting is the most popular method and has been researched over the past two decades.Wi-Fi positioning faces three core problems:device heterogeneity,robustness to signal changes caused by human mobility,and device attitude,i.e.,varying orientations.The existing methods do not cover these aspects owing to the unavailability of publicly available datasets.This study introduces a dataset that includes the Wi-Fi received signal strength(RSS)gathered using four different devices,namely Samsung Galaxy S8,S9,A8,LG G6,and LG G7,operated by three surveyors,including a female and two males.In addition,three orientations of the smartphones are used for the data collection and include multiple buildings with a multifloor environment.Various levels of human mobility have been considered in dynamic environments.To analyze the time-related impact on Wi-Fi RSS,data over 3 years have been considered.

Indoor 3D Reconstruction Using Camera, IMU and Ultrasonic Sensors

The recent advances in sensing and display technologies have been transforming our living environments drastically. In this paper, a new technique is introduced to accurately reconstruct indoor environments in three-dimensions using a mobile platform. The system incorporates 4 ultrasonic sensors scanner system, an HD web camera as well as an inertial measurement unit (IMU). The whole platform is mountable on mobile facilities, such as a wheelchair. The proposed mapping approach took advantage of the precision of the 3D point clouds produced by the ultrasonic sensors system despite their scarcity to help build a more definite 3D scene. Using a robust iterative algorithm, it combined the structure from motion generated 3D point clouds with the ultrasonic sensors and IMU generated 3D point clouds to derive a much more precise point cloud using the depth measurements from the ultrasonic sensors. Because of their ability to recognize features of objects in the targeted scene, the ultrasonic generated point clouds performed feature extraction on the consecutive point cloud to ensure a perfect alignment. The range measured by ultrasonic sensors contributed to the depth correction of the generated 3D images (the 3D scenes). Experiments revealed that the system generated not only dense but precise 3D maps of the environments. The results showed that the designed 3D modeling platform is able to help in assistive living environment for self-navigation, obstacle alert, and other driving assisting tasks.

A novel particle filter approach for indoor positioning by fusing WiFi and inertial sensors

WiFi fingerprinting is the method of recording WiFi signal strength from access points （AP） along with the positions at which they were recorded, and later matching those to new mea- surements for indoor positioning. Inertial positioning utilizes the accelerometer and gyroscopes for pedestrian positioning. However, both methods have their limitations, such as the WiFi fluctuations and the accumulative error of inertial sensors. Usually, the filtering method is used for integrating the two approaches to achieve better location accuracy. In the real environments, especially in the indoor field, the APs could be sparse and short range. To overcome the limitations, a novel particle filter approach based on Rao Blackwellized particle filter （RBPF） is presented in this paper. The indoor environment is divided into several local maps, which are assumed to be independent of each other. The local areas are estimated by the local particle filter, whereas the global areas are com- bined by the global particle filter. The algorithm has been investigated by real field trials using a WiFi tablet on hand with an inertial sensor on foot. It could be concluded that the proposed method reduces the complexity of the positioning algorithm obviously, as well as offers a significant improvement in position accuracy compared to other conventional algorithms, allowing indoor positioning error below 1.2 m.

双足人形机器人定位及运动规划系统的设计与实现

基于ZigBee技术和多传感器数据融合设计并实现了双足人形机器人的室内定位与运动规划控制系统,并分别对机器人运动过程建立空间模型和姿态模型,以获得机器人实时位置及姿态信息,实现自主运动规划。系统将树莓派4B和32路串口总线舵机控制板结合起来作为核心控制平台,更好地实现了对机器人的方向控制、目标导航等功能。

基于TOA与AOA算法的室内定位方法

为了解决传统室内定位技术成本较高、稳定性差以及难于部署等问题,提出一种将到达时间(time of arrival,TOA)与到达角(angle of arrival,AOA)相结合的室内定位系统.该系统由定位基站与被控定位单元组成,其特征在于使用对射式布置的超声波传感器获取定位基站与被控定位单元之间的距离特征,利用角度传感器获取被控定位单元相对于定位基站的角度特征,以单基站就实现了精确的室内定位过程.分析了该系统基本结构与原理,建立定位与控制模型,在一定范围内对其定点定位精度与跟随定位精度进行了实验验证.实验结果表明:该系统结构简单,易于安装布置,鲁棒性强,在测试范围内的最大定点定位误差不超过5 cm,跟随定位误差不超过15 cm.

基于光电传感器的学前儿童机器人室内自动定位方法

针对学前儿童机器人在与儿童的互动和个性化的陪伴方面,机器人仍不能满足人们的需要。为了提高机器人与儿童的互动性,需要使机器人具备室内自动定位的功能,本文基于光电传感器对学前儿童机器人进行设计。机器人的任务系统按照功能层次可以分为人机交互层、控制层、任务组织层和任务执行层。通过改进机器人定位方式,采用光电图像传感器进行距离测量以提高行进过程中定位精度,实现机器人的自动定位。根据室内障碍物较多的特点,对人工势场算法改进,对机器人的路径进行规划算法,从而设计了机器人的避障规则。为验证该学前儿童机器人的性能,对机器人进行自动定位和路径规划试验。试验结果表明:机器人的自动定位结果准确,定位偏差均小于5%,且可进行路径规划和避障。

基于微气压传感器的室内行人高度估计方法

针对当前气压传感器解算高度存在误差随时间累积的问题,提出了一种基于微气压传感器的室内行人高度估计新方法。该方法结合微气压传感器的输出高度值,对多个相邻时间内的高度值进行合理性判断,并结合室内行人运动状态对高度变化进行约束,使得解算的高度符合室内行人运动规律。通过电脑采集MS5611微气压传感器数据进行仿真验证,结果表明:该方法能够有效地对高度误差进行修正,相较于微气压传感器直接解算的高度,该算法解算的高度更贴合实际情况,解算轨迹也更接近真实轨迹,轨迹的平均闭环误差从1.9%D下降至0.07%D。该算法有效地提高了室内行人高度估计的定位精度,在室内行人三维定位领域具有一定的工程应用价值。

基于视觉和惯性传感器的大型邮轮室内旅客身份识别方法

邮轮内部结构及场景复杂,基于监控用单目摄像头的旅客身份识别方法缺乏深度信息,无法准确识别旅客位置、航向及航向变化信息,难以在复杂场景下准确识别旅客身份。针对上述问题,提出了基于监控用单目摄像头与手持惯性传感器的大型邮轮室内旅客身份识别方法。根据YOLOv5视觉目标检测算法,提取监控视频帧中旅客的像素坐标与边界框;利用2D-3D坐标转换公式,将相机图像中旅客的像素坐标转换为物理世界中旅客与相机的相对坐标;再基于改进神经网络模型,估计旅客在相机相对坐标系下的航向角。利用旅客智能手机中惯性传感器,采集旅客运动数据,检测旅客加速度的变化,判别旅客行走状态;融合磁场强度,推算旅客在大地坐标系下的真实航向角;融合提取的视觉和惯性传感器数据,对旅客的有限特征及其关系进行编码,包括瞬时时刻行走状态、步长、相对航向角和相对距离,解决传感器信号的误差累积问题;基于构建的2幅多关联图,提出特征之间的相似度计算公式,再利用视觉与惯性传感器特征图匹配(vision and inertial sensors graph matching,VIGM)算法求解最大相似度矩阵,实现对2幅图中的同一旅客的识别。经长江“黄金3号”邮轮大厅、棋牌室、多功能厅和走廊4个场景实验,可以发现:VIGM算法在1~3 s窗口内平均匹配准确率达83.9%,与使用高成本深度相机的ViTag身份匹配算法相比,平均匹配准确率仅相差4.5%。实验结果表明:所提基于摄像头与惯性传感器的旅客身份识别方法及算法实现成本低,但识别效果与使用高成本深度相机的方法相当。

改进AMCL最优位姿估计的机器人室内定位控制

机器人在室内定位过程中存在定位精准度不高、定位时间长等问题,为此,提出改进AMCL最优位姿估计的机器人室内定位控制系统。构建机器人信息采集系统,采集机器人室内位置信息;改进阈值函数,对传感器信号实行去噪处理,为其精准定位打下基础;利用卡尔曼滤波数据,获得机器人的最优位姿估计,实现最终的机器人室内定位。实验结果表明,所提方法的定位误差均在0.3m以内,定位精准度更高,定位偏差小,定位效果较好。

Floor positioning method indoors with smartphone’s barometer

This paper presents an indoor floor positioning method with the smartphone’s barometer for the purpose of solving the problem of low availability and high environmental dependence of the traditional floor positioning technology.First,an initial floor position algorithm with the“entering”detection algorithm has been obtained.Second,the user’s going upstairs or downstairs activities are identified by the characteristics of the air pressure fluctuation.Third,the moving distance in the vertical direction and the floor change during going upstairs or downstairs are estimated to obtain the accurate floor position.In order to solve the problem of the floor misjudgment from different mobile phone’s barometers,this paper calculates the pressure data from the different cell phones,and effectively reduce the errors of the air pressure estimating the elevation which is caused by the heterogeneity of the mobile phones.The experiment results show that the average correct rate of the floor identification is more than 85%for three types of the cell phones while reducing environmental dependence and improving availability.Further,this paper compares and analyzes the three common floor location methods–the WLAN Floor Location(WFL)method based on the fingerprint,the Neural Network Floor Location(NFL)methods,and the Magnetic Floor Location(MFL)method with our method.The experiment results achieve 94.2%correct rate of the floor identification with Huawei mate10 Pro mobile phone.

基于最大熵模糊概率数据关联的室内定位算法

无线传感器网络(wireless sensor network,WSN)由多个微传感器节点组成,定位技术是无线传感器网络技术的重要应用之一。目前,许多定位算法在视距(line of sight,LOS)环境下定位精度较高,但在非视距(non line of sight,NLOS)环境下的定位精度较差。为了解决这一问题,提出一种改进的基于到达时间的最大熵模糊概率数据关联算法。采用分组的思想将N个测量值分为L组,每组通过交互式多模型(interactive multi model,IMM)算法获得相应的移动节点位置估计、模型概率和协方差矩阵。然后将得到的L个位置估计,通过验证门进行非视距检测,丢弃被非视距误差污染的位置估计,利用相应的关联概率对正确的位置估计进行加权得到最终的位置估计。仿真和实验结果表明,与现有方法相比,该算法可以减轻非视距误差的影响,实现更高的定位精度。

基于惯导辅助地磁的手机室内定位系统设计

目前的室内定位技术大都是需要建立足够多的信号节点,这种有源信号受建筑物干扰衰减快导致其定位精度不足。为了避免这些存在的问题,通过深入研究室内定位方法,提出了基于惯导辅助地磁匹配的适用于手机移动终端的室内定位方法。有别于传统的室外定位系统,本文利用地球磁场在不同点的差异化信息,并通过选择适当的地磁匹配算法,可以实现不依赖于外部设备的移动个体室内定位,同时通过惯导辅助地磁的组合定位方式有效增加地磁信息匹配效率,能获得较高的室内定位的精度。最后设计了基于android平台的手机室内定位软件,可利用手机内置的传感器设备实现室内定位功能,仿真及实验显示该定位方法是有效的。

无线网络室内定位系统研究

分析了无线网络室内定位系统的基本模型及主要问题和难点,并从不同角度提出多个分类标准.随后详细介绍了多个典型无线室内定位系统的实现方法,并分析其优劣点.最后指出商业推广需要进一步完成的工作及未来的研究方向.

一种基于卡尔曼数据平滑的分段曲线拟合室内定位算法

室内定位技术的关键在于获取距离参数,在这一问题的研究中运用RSSI信号获得距离参数一直是比较通行的方法.本文针对室内环境复杂,接收RSSI信号存在较大噪声的情况,提出了一种运用卡尔曼滤波器对信号数据进行平滑预处理,随后利用最小二乘法进行分段曲线拟合从而实现定位的算法.通过实验测试结果表明,本文所提出的算法平均定位精度可达0.9 m,与普通数据平均值预处理算法和曲线直接拟合方法相比较,定位精度更高;比直接应用对数距离损耗路径模型的定位算法更为合理可靠,能够在一定程度上满足无线传感器网络室内定位需求.

无线定位与惯性导航结合的室内定位系统设计

面对室内定位的实际应用需求,分析了基于接收信号强度指纹法定位技术精度较低、单纯的惯性导航累积误差较大等问题,采用基于信赖度的联合定位算法对多种信息进行融合处理,以获得较高的综合定位精度。通过基于ZigBee的无线传感器网络平台及多种MEMS运动传感器的联合,设计并实现了多信息融合的室内定位演示系统。由于多种信息的融合,不需要依赖大量样本的指纹库,从而降低了实现过程中离线指纹库建立的工作量。经实验数据分析,基于信赖度的联合定位方法具有较高的定位精度和较低的实现复杂度。

一种基于智能手机传感器的行人室内定位算法

智能手机及其内置惯性传感器的普及可实现室内行人航位推算,但是由于人行走的随意性以及智能手机内置传感器精度不高,使定位精度难以满足应用要求。为此,在分析行人行走模式的基础上,基于智能手机传感器提出一种新的行人航位推算算法。对采集到的原始加速度数据进行预处理,采用基于有限状态机的行走状态转换方法识别行走周期并进行计步,利用卡尔曼滤波,结合步长-加速度关系以及连续两步步长之间的关系对步长进行估计。实验结果表明,该算法能够准确计算步数和步长,从而获得精确的室内定位结果。

WiFi-PDR室内组合定位的无迹卡尔曼滤波算法

针对当前室内定位的应用需求和亟待解决的关键问题,结合城市室内环境下广泛存在的WiFi无线信号以及智能手机传感器信息,提出了一种WiFi无线信号联合行人航迹推算(PDR)的室内定位方法。该方法采用无迹卡尔曼滤波(UKF)算法对WiFi和PDR定位信息进行融合处理,有效克服了WiFi单点定位精度低和PDR存在累计误差的问题。针对融合算法中WiFi指纹匹配计算量大的问题,用k-means聚类算法对WiFi指纹库进行聚类处理,降低了指纹匹配算法的计算量,提高了算法的实时性。通过在华为P6-U06智能手机平台上实际测试,在时间效率上经过聚类处理后系统定位耗时有很大程度的改善,平均降幅为51%,其中最大降幅达到64%,最小的也达到了36%;在定位精度上,当室内人员为行走状态时WiFi定位平均误差为7.76m,PDR定位平均误差为4.57m,UKF滤波融合后平均定位误差下降到1.24m。

自适应无线传感器网络室内定位算法研究

传统的基于接收信号强度测距定位需要人工建模获取定位场景的先验测距模型参数,无法适应复杂及动态变化的环境。利用参考节点之间相互通信为每个参考节点赋予不同的路径损耗指数的特性,实现了室内定位的自适应和自动化。测试结果表明,与采用单一的测距模型参数相比,该算法提高了定位精度。

基于EC-TDOA和ZigBee技术的室内超声波定位系统

目的研究室内定位方法机理,解决室内目标高精度定位的问题.方法设计了一种基于测距的室内定位系统,该系统采用测量射频信号和超声波信号到达时间差的方法测距并引入校正因子减小测距误差,通过极大似然估计定位方法计算目标位置,运用ZigBee制作节点模块组成网络实现对室内目标的定位.结果在测距实验中,EC-TDOA测距结果的误差小于0.02 cm,满足测距精度要求.在定位实验中,最大定位误差和平均定位误差分别为4.3 cm和1.64 cm,而定位误差在2.5 cm以内的比例达到90%.定位频率为20 Hz,满足实时定位的要求.结论系统在室内环境中实现对超声波信号覆盖范围内移动节点的定位,通过测距校正有效提高定位精度.系统具有较强的容错性和自适应性..