Indoor localization using controlled ambient sounds

Abstract

Abstract-Audio-based receiver localization in indoor environments has multiple applications including indoor navigation, location tagging, and tracking. Public places like shopping malls and consumer stores often have loudspeakers installed to play music for public entertainment. Similarly, office spaces may have sound conditioning speakers installed to soften other environmental noises. We discuss an approach to leverage this infrastructure to perform audio-based localization of devices requesting localization in such environments, by playing barely audible controlled sounds from multiple speakers at known positions. Our approach can be used to localize devices such as smart-phones, tablets and laptops to sub-meter accuracy. The user does not need to carry any specialized hardware. Unlike acoustic approaches which use high-energy ultrasound waves, the use of barely audible (low energy) signals in our approach poses very different challenges. We discuss these challenges, how we addressed those, and experimental results on two prototypical implementations: a request-play-record localizer, and a continuous tracker. We evaluated our approach in a real world meeting room and report promising initial results with localization accuracy within half a meter 94% of the time. The system has been deployed in multiple zones of our office building and is now part of a location service in constant operation in our lab.

Acoustic Self-Calibrating System for Indoor Smart Phone Tracking

“…In this case, a very precise position measurement is possible. Rishabh et al use the loudspeakers which are installed in shopping malls and consumer stores to play music for public entertainment [25]. The use of barely audible (low energy) pseudorandom sequences in their approach poses very different challenges to other approaches which use highenergy ultrasound waves.…”

A State-of-the-Art Survey of Indoor Positioning and Navigation Systems and Technologies

“…Unlike the Ultrasound positioning system, which has a limited range because of high attenuation while propagating in the air, the Audible Sound positioning system is not limited in range (Rishabh, Kimber, & Adcock, 2012). Audible Sound positioning system is a system where the position of a person or an object is determined in a building by using audible sound waves through sound cards of standard devices (Mautz, 2012;Fallah et al, 2013).…”

“…Examples of such a system are Beep, BeepBeep and Guoguo as demonstrated in the studies of Mandal et al (2005), Peng, Shen, and Zhang (2012), K. Liu et al (2013) respectively. Other examples include the studies of Höflinger et al (2012), Rishabh et al (2012), Sertatil, Altinkaya, and Raoof (2012). The working operation of these systems is the same even though they consist of different but similar hardware and architecture.…”

“…The studies of Mandal et al (2005), Höflinger et al (2012), Rishabh et al (2012), K. Liu et al (2013) consist of mobile devices (e.g. mobile phone), acoustic receivers, central server and wireless network.…”

“…With this information, the central server computes the position of the mobile device and sends the information to the mobile device. While the mobile device acts as a transmitter in the positioning system of these studies, the usage of the mobile device differs in the study of Rishabh et al (2012). The mobile device, in this case, acts as the receiver through the device's microphone.…”