基于WiFi的便携式室内定位系统

Portable indoor positioning system based on WiFi

针对全球定位系统无法满足室内定位的问题,基于Android平台开发了利用Wi Fi信号特征的便携式室内定位系统.该系统由移动定位终端、服务器和数据库组成,移动定位终端和服务器联合完成定位功能.定位算法采用基于接收信号强度指示(RSSI)的指纹算法,以场景分析的手段估算出移动定位终端的坐标.在线定位阶段,采用欧氏距离平方倒数作为权重系数对K最近邻算法的权重系数进行改进,以减小在线阶段的误差.实验表明,系统便于携带,操作简单,单次定位速度小于3 s,并且系统3 m内的定位精度达到80%以上.

To the question which the global positioning system can＇ t meet the requirements of indoor location,the paper gives a portable indoor positioning system which is based on Android platform and developed by using the Wi Fi received signal strength（RSSI）.The system is consisted of a mobile location terminal,a server and a database.The mobile positioning terminal and server perform the indoor positioning jointly.The location algorithm uses the technology of the RSSI fingerprinting.The coordinates of the mobile location terminal are estimated by means of the scene analysis.In the online positioning stage,the weight coefficient of the nearest neighbor algorithm is substituted by using reciprocal of the Euclidean distance square as the weight coefficient in order to reduce the error in the online phase.The experiment results show that the system is easy to be carried and operated.The positioning speed is below 3 s and the positioning accuracy in range of 3 m is above 80%.