Towards Zero-Configuration Indoor Localization Using Asynchronous Acoustic Beacons

Developing and deploying infrastructure-based indoor localization solutions face significant challenges in the need of specialized user devices, costly and elaborative installation, configuration and maintenance, and in some cases, low localization accuracy. In this work, we develop an acoustic indoor localization system that requires little configuration and can localize commercial off-the-shelf smart phone devices. The main novelty lies in the development of a Time-Difference-of-Arrival (TDoA)-based ranging algorithm that does not require clock synchronization among infrastructure nodes (called anchors) and utilizes passive target devices. Small-scale experiments using Android mobile phones as both anchor nodes and target devices demonstrate the feasibility of the proposed solution. The 95% quantile localization errors achieved are consistently less than 7.5cm using three models of Android smart phones from different vendors as target devices when the closest two anchors are 1 meter apart.