基于临近听域超声波TDOA室内定位的实现

Realization of TDOA-Based Indoor Positioning Using Nearing Audible Area Ultrasound

介绍了一种便于部署的超声波室内定位系统。通过普通高音喇叭可以发射的20～22kHz超声波频段,本文实现了基于3个高音喇叭信号源的超声波到达时间差(Time difference of arrival,TDOA)的定位。普通手机通过麦克风采集该频段的超声波,经过信号处理后实现了高精度、低成本的室内定位。本文在定位系统中设计了发射端超声波定位声源的信号结构,并设计了接收端通过频率搜索和基于快速傅里叶变换的频域搜索的同步方法。同时本文还将一种修正秩-1拟牛顿法应用到了基于TDOA的定位场景中,并验证了在使用3个高音喇叭时该算法定位精度与经典的CHAN算法基本相同。实验中本方法采用了不同于以往的40kHz超声波频段的定位方案,在使用普通手机接收的条件下,各次实验结果误差均低于9cm。

This paper presents an ultrasonic indoor positioning system which is easy to be deployed.Ultrasonic signal whose bandwidth is 20-22 kHz can be transmitted by ordinary tweeters.This paper realizes the time difference of arrival(TDOA)positioning based on ultrasound transmitted by three tweeters.A mobile phone collects ultrasonic signal in this band by microphone.A high accuracy,low-cost indoor positioning can be achieved after signal processing.Signal structure of ultrasonic positioning acoustic source is designed at the transmitter.A synchronization method based on frequency search and FFT search is used at the receiver.A modified SR-1 method is used in positioning scenario based on TDOA.This paper validates that the accuracy of modified SR-1 method is basically the same as the classical CHAN algorithm when three tweeters are used in the scenario.The band of the ultrasonic signal which is used in our scheme is fairly different from those commonly-used scheme whose signal band is 40 kHz.The error is less than 9 cm in every experiment under the condition of receiving ultrasonic signal by an ordinary phone.