The multipath effect and movements of people in indoor environments lead to inaccurate localization. Through the test, calculation and analysis on the received signal strength indication (RSSI) and the variance of R...The multipath effect and movements of people in indoor environments lead to inaccurate localization. Through the test, calculation and analysis on the received signal strength indication (RSSI) and the variance of RSSI, we propose a novel variance-based fingerprint distance adjustment algorithm (VFDA). Based on the rule that variance decreases with the increase of RSSI mean, VFDA calculates RSSI variance with the mean value of received RSSIs. Then, we can get the correction weight. VFDA adjusts the fingerprint distances with the correction weight based on the variance of RSSI, which is used to correct the fingerprint distance. Besides, a threshold value is applied to VFDA to improve its performance further. VFDA and VFDA with the threshold value are applied in two kinds of real typical indoor environments deployed with several Wi-Fi access points. One is a quadrate lab room, and the other is a long and narrow corridor of a building. Experimental results and performance analysis show that in indoor environments, both VFDA and VFDA with the threshold have better positioning accuracy and environmental adaptability than the current typical positioning methods based on the k-nearest neighbor algorithm and the weighted k-nearest neighbor algorithm with similar computational costs.展开更多
In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accele...In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accelerated and angular rotated speed of moving objects. Meanwhile, the ranges from the object to beacons, which are sensor nodes with known coordinates, are collected by time of arrival (ToA) approach. These messages are simultaneously collected and transmitted to the terminal. At the terminal, we set up the state transition models and observation models. According to them, several recursive Bayesian algorithms are applied to producing position estimations. As shown in the experiments, all of three algorithms do not require constant moving speed and perform better than standalone ToA system or standalone IMU system. And within them, two algorithms can be applied for the tracking on any path which is not restricted by the requirement that the trajectory between the positions at two consecutive time steps is a straight line.展开更多
近年来随着经济的发展,室内定位系统的需求越来越迫切.传统的室内定位系统如WIFI定位和蓝牙定位面临着定位精度低、易受非视距(non-line-of-sight,NLOS)和噪声干扰等挑战.针对这些问题,提出了一种基于融合集成学习的近超声室内定位方法...近年来随着经济的发展,室内定位系统的需求越来越迫切.传统的室内定位系统如WIFI定位和蓝牙定位面临着定位精度低、易受非视距(non-line-of-sight,NLOS)和噪声干扰等挑战.针对这些问题,提出了一种基于融合集成学习的近超声室内定位方法.首先,使用优化的增强互相关方法有效地抵消多径干扰.与传统基于峰值提取或固定阈值的方法相比,此法在混响环境中明显提升了测距的精度.然后,利用到达时间差(time difference of arrival,TDOA)作为特征进行提取.最终,采用了融合集成学习模型,对设定好的训练集进行交叉融合训练,并输入特征,从而得到修正的定位结果.仿真和实验测试结果表明,所提出的方法可以在室内NLOS和噪声干扰的情况下克服较大误差实现精确定位,并且精度优于对比方法50%~90%.本文核心数据公布在https://github.com/ChirsJia/JSJYF上.展开更多
基金supported by the National Natural Science Foundation of China(6120200461472192)+1 种基金the Special Fund for Fast Sharing of Science Paper in Net Era by CSTD(2013116)the Natural Science Fund of Higher Education of Jiangsu Province(14KJB520014)
文摘The multipath effect and movements of people in indoor environments lead to inaccurate localization. Through the test, calculation and analysis on the received signal strength indication (RSSI) and the variance of RSSI, we propose a novel variance-based fingerprint distance adjustment algorithm (VFDA). Based on the rule that variance decreases with the increase of RSSI mean, VFDA calculates RSSI variance with the mean value of received RSSIs. Then, we can get the correction weight. VFDA adjusts the fingerprint distances with the correction weight based on the variance of RSSI, which is used to correct the fingerprint distance. Besides, a threshold value is applied to VFDA to improve its performance further. VFDA and VFDA with the threshold value are applied in two kinds of real typical indoor environments deployed with several Wi-Fi access points. One is a quadrate lab room, and the other is a long and narrow corridor of a building. Experimental results and performance analysis show that in indoor environments, both VFDA and VFDA with the threshold have better positioning accuracy and environmental adaptability than the current typical positioning methods based on the k-nearest neighbor algorithm and the weighted k-nearest neighbor algorithm with similar computational costs.
基金Project(61301181) supported by the National Natural Science Foundation of China
文摘In this paper, we integrate inertial navigation system (INS) with wireless sensor network (WSN) to enhance the accuracy of indoor localization. Inertial measurement unit (IMU), the core of the INS, measures the accelerated and angular rotated speed of moving objects. Meanwhile, the ranges from the object to beacons, which are sensor nodes with known coordinates, are collected by time of arrival (ToA) approach. These messages are simultaneously collected and transmitted to the terminal. At the terminal, we set up the state transition models and observation models. According to them, several recursive Bayesian algorithms are applied to producing position estimations. As shown in the experiments, all of three algorithms do not require constant moving speed and perform better than standalone ToA system or standalone IMU system. And within them, two algorithms can be applied for the tracking on any path which is not restricted by the requirement that the trajectory between the positions at two consecutive time steps is a straight line.
文摘近年来随着经济的发展,室内定位系统的需求越来越迫切.传统的室内定位系统如WIFI定位和蓝牙定位面临着定位精度低、易受非视距(non-line-of-sight,NLOS)和噪声干扰等挑战.针对这些问题,提出了一种基于融合集成学习的近超声室内定位方法.首先,使用优化的增强互相关方法有效地抵消多径干扰.与传统基于峰值提取或固定阈值的方法相比,此法在混响环境中明显提升了测距的精度.然后,利用到达时间差(time difference of arrival,TDOA)作为特征进行提取.最终,采用了融合集成学习模型,对设定好的训练集进行交叉融合训练,并输入特征,从而得到修正的定位结果.仿真和实验测试结果表明,所提出的方法可以在室内NLOS和噪声干扰的情况下克服较大误差实现精确定位,并且精度优于对比方法50%~90%.本文核心数据公布在https://github.com/ChirsJia/JSJYF上.
文摘在室内定位服务中,WiFi指纹技术因其覆盖面积广、定位精度高而受到人们的广泛关注.然而,对于在线阶段的位置查询,用户的个人敏感信息容易受到恶意攻击而造成位置隐私泄露.现有基于WiFi指纹的室内定位技术仅考虑室内单一空旷平面,这使得WiFi部署的灵活性受到限制.而当WiFi部署在多维场景时,空间位置隐私问题亟待解决.提出了一种基于地理不可区分性的WiFi指纹室内定位隐私保护方案,用户利用自身接收信号强度生成一个新的接收信号强度向量,并通过加噪混淆将得到的数据发送给位置服务提供商,同时引入数字签名技术,在混淆位置被发送给位置服务提供商实现定位之前确保客户端身份不被伪造.基于模拟实验平台的实验结果表明,该方案支持WiFi的灵活部署,能够在保护位置隐私的同时,首次实现12个WiFi接入点灵活部署情况下的高精度定位,保证定位误差小于1 m.