基于无线传感器网络与无迹卡尔曼滤波的室内定位系统设计

Design of Indoor Localization System Based on Wireless Sensor Networks and Unscented Kalman Filter

基于接收信号强度指示(Received Signal Strength Indicator,RSSI)的测距方法和无迹卡尔曼滤波(Unscented Kalman Filter,UKF)实现了一种无线传感器网络室内定位系统。系统主要由协调器节点、锚节点和盲节点组成,首先由盲节点发送RSSI信标信号至锚节点处,锚节点接收信标信号后做均值处理,并将自身位置信息一起打包回发给盲节点;然后盲节点将定位信息的相关数据通过协调器无线发送至上位机;最后在上位机中完成对盲节点的定位计算。为进一步提高定位精度,首先应用三边定位方法获得盲节点的初步定位结果,然后采用无迹卡尔曼滤波实现了二次精确定位。使用C#语言开发上位机软件,在20 m×20 m的定位范围内,对10个随机位置处的盲节点进行了定位测试,其中最大定位误差为1.52 m,最小误差为0.50 m,平均定位误差为1.04 m。结果表明所提出的定位算法性能良好,系统定位方案切实有效。

Indoor location system of wireless sensor network based on received signal strength indicator(RSSI)and unscented Kalman filter(UKF)is designed.The system is composed of three parts,including coordinator node,anchor node and blind node.RSSI beacon signal from blind node is sent to anchor node firstly,anchor node takes the average value of the RSSI data after received the signal and sends back to blind node with its own position data.Then,the data relevant to position calculation of the blind node is sent to computer through coordinator node.At last,location calculation of blind node is implemented on the software platform of the computer.In order to further improve the positioning accuracy,the initial positioning results of blind node are calculated by using the trilateral positioning method,and then the secondary accurate positioning is realized by unscented kalman filter.The upper computer software is developed using the C#lan-guage,and the indoor positioning test is carried out.Within the positioning range of 20 m×20 m,the blind nodes at 10 random locations are tested for positioning,of which the maximum positioning error is 1.52 m,the minimum error is 0.50 m,and the average positioning error is 1.04 m.The results show that the proposed positioning algorithm has good performance and the desingned system scheme is effective.