ARABIS: an Asynchronous Acoustic Indoor Positioning System for Mobile Devices

TL;DR

ARABIS is a robust, low-cost acoustic indoor positioning system for mobile devices that improves accuracy in challenging environments by mitigating multi-path and low SNR issues through a novel iterative outlier removal algorithm.

Contribution

The paper introduces ARABIS, a novel asynchronous acoustic indoor positioning system with a custom-designed low-cost hardware and a robust algorithm for improved accuracy in indoor environments.

Findings

Achieves 7.4cm average error in a 10.67m*7.76m testbed.

Achieves 20.4cm average error in a 15m*15m testbed.

Effective mitigation of multi-path and low SNR effects.

Abstract

Acoustic ranging based indoor positioning solutions have the advantage of higher ranging accuracy and better compatibility with commercial-off-the-self consumer devices. However, similar to other time-domain based approaches using Time-of-Arrival and Time-Difference-of-Arrival, they suffer from performance degradation in presence of multi-path propagation and low received signal-to-noise ratio (SNR) in indoor environments. In this paper, we improve upon our previous work on asynchronous acoustic indoor positioning and develop ARABIS, a robust and low-cost acoustic positioning system (IPS) for mobile devices. We develop a low-cost acoustic board custom-designed to support large operational ranges and extensibility. To mitigate the effects of low SNR and multi-path propagation, we devise a robust algorithm that iteratively removes possible outliers by taking advantage of redundant TDoA estimates. Experiments have been carried in two testbeds of sizes 10.67m*7.76m and 15m*15m, one in an academic building and one in a convention center. The proposed system achieves average and 95% quantile localization errors of 7.4cm and 16.0cm in the first testbed with 8 anchor nodes and average and 95% quantile localization errors of 20.4cm and 40.0cm in the second testbed with 4 anchor nodes only.