Misalignment Recognition in Acoustic Sensor Networks using a Semi-supervised Source Estimation Method and Markov Random Fields

TL;DR

This paper introduces a semi-supervised method using Markov Random Fields to detect and identify displaced nodes in acoustic sensor networks, improving localization accuracy in changing environments.

Contribution

The paper presents a novel probabilistic approach combining leave-one-node-out estimates and MRFs for misalignment detection in acoustic sensor networks.

Findings

Effective detection of displaced nodes across various acoustic conditions

Improved localization accuracy by identifying misaligned sensors

Probabilistic framework outperforms naive detection methods

Abstract

In this paper, we consider the problem of acoustic source localization by acoustic sensor networks (ASNs) using a promising, learning-based technique that adapts to the acoustic environment. In particular, we look at the scenario when a node in the ASN is displaced from its position during training. As the mismatch between the ASN used for learning the localization model and the one after a node displacement leads to erroneous position estimates, a displacement has to be detected and the displaced nodes need to be identified. We propose a method that considers the disparity in position estimates made by leave-one-node-out (LONO) sub-networks and uses a Markov random field (MRF) framework to infer the probability of each LONO position estimate being aligned, misaligned or unreliable while accounting for the noise inherent to the estimator. This probabilistic approach is advantageous over naive detection methods, as it outputs a normalized value that encapsulates conditional information provided by each LONO sub-network on whether the reading is in misalignment with the overall network. Experimental results confirm that the performance of the proposed method is consistent in identifying compromised nodes in various acoustic conditions.