Source Localization With Isotropic Arrays

Oktel, U.; Moses, Randolph L.

doi:10.1109/lsp.2004.826636

Cited by 5 publications

(5 citation statements)

References 6 publications

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“…It is noteworthy that the DoA variance is constant also when the time delay covariance terms are not neglected both for the case of wave velocity known and unknown, and the optimal disks cluster is given by an equilateral triangle (see [ 23 , 32 ]).…”

Section: Optimal Time Delays–doa Functions Derivationmentioning

confidence: 99%

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An Optimal Shaped Sensor Array Derivation

Dibiase

Marchi

2023

Micromachines

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In Structural Health Monitoring (SHM) applications, the Direction of Arrival (DoA) estimation of Guided Waves (GW) on sensor arrays is often used as a fundamental means to locate Acoustic Sources (AS) generated by damages growth or undesired impacts in thin-wall structures (e.g., plates or shells). In this paper, we consider the problem of designing the arrangement and shape of piezo-sensors in planar clusters in order to optimize the DoA estimation performance in noise-affected measurements. We assume that: (i) the wave propagation velocity is unknown, (ii) the DoA is estimated via the time delays of wavefronts between sensors, and (iii) the maximum value of the time delays is limited. The optimality criterion is derived basing on the Theory of Measurements. The sensor array design is so that the DoA variance is minimized in an average sense by exploiting the Calculus of Variations. In this way, considering a three-sensor cluster and a monitored angles sector of 90°, the optimal time delays–DoA relations are derived. A suitable re-shaping procedure is used to impose such relations and, at the same time, to induce the same spatial filtering effect between sensors so that the sensor acquired signals are equal except for a time-shift. In order to achieve the last aim, the sensors shape is realized by exploiting a technique called Error Diffusion, which is able to emulate piezo-load functions with continuously modulated values. In this way, the Shaped Sensors Optimal Cluster (SS-OC) is derived. A numerical assessment via Green’s functions simulations shows improved performance in DoA estimation by means of the SS-OC when compared to clusters realized with conventional piezo-disk transducers.

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Section: Optimal Time Delays–doa Functions Derivationmentioning

confidence: 99%

“…Comparison of Standard Deviation (SD) and Maximum Error (ME) values (in degrees)between the arrays of Figures1 and 6for noise-affected measurements (AWGN) at different PSNR values. Actuated pulse band:[30][31][32][33][34][35][36][37][38][39][40] kHz.…”

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confidence: 99%

An Optimal Shaped Sensor Array Derivation

Dibiase

Marchi

2023

Micromachines

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“…Conversely, when the wave velocity is known, the optimized array would be symmetric w.r.t the X-axis [ 14 ]. This particular configuration is due to the minimization of the DoA accuracy loss due to the unknown wave velocity [ 32 ], via Equation ( 13 ). The obtained 3-sensor cluster will be referred to as Designed Cluster (DC) while the configuration of Figure 1 a, which is related to the cluster proposed by Kundu et al in [ 10 , 11 ], will be referred to as Standard Cluster (SC) in this paper.…”

Section: Cost Function and Array Geometry Designmentioning

confidence: 99%

Optimal Array Design and Directive Sensors for Guided Waves DoA Estimation

Dibiase

Mohammadgholiha

Marchi

2022

Sensors

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The estimation of Direction of Arrival (DoA) of guided ultrasonic waves is an important task in many Structural Health Monitoring (SHM) applications. The aim is to locate sources of elastic waves which can be generated by impacts or defects in the inspected structures. In this paper, the array geometry and the shape of the piezo-sensors are designed to optimize the DoA estimation on a pre-defined angular sector, from acquisitions affected by noise and interference. In the proposed approach, the DoA of a wave generated by a single source is considered as a random variable that is uniformly distributed in a given range. The wave velocity is assumed to be unknown and the DoA estimation is performed by measuring the Differences in Time of Arrival (DToAs) of wavefronts impinging on the sensors. The optimization procedure of sensors positioning is based on the computation of the DoA and wave velocity parameters Cramér-Rao Matrix Bound (CRMB) with a Bayesian approach. An efficient DoA estimator is found based on the DToAs Gauss-Markov estimator for a three sensors array. Moreover, a novel directive sensor for guided waves is introduced to cancel out undesired Acoustic Sources impinging from DoAs out of the given angles range. Numerical results show the capability to filter directional interference of the novel sensor and a considerably improved DoA estimation performance provided by the optimized sensor cluster in the pre-defined angular sector, as compared to conventional approaches.

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“…The described signal model and estimation procedure can be used for any array geometry. In the experiments, we have used a uniform circular array (UCA) since the DOA estimation performance is independent of the direction of the source [15,16] and fast estimation algorithms for it exist [17]. Moreover, a UCA is often used in smart speakers.…”

Section: Source Localisationmentioning

confidence: 99%

Loudspeaker and Listening Position Estimation Using Smart Speakers

Nielsen

2018

2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

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Recently, so-called smart speakers have been introduced and they include a microphone array. One potential application of such a smart speaker is to use it for calibrating a larger audio system which the speaker is a part of. In this paper, we propose a method to perform this calibration using one or several smart speakers. Specifically, a map is estimated of the sensors and sound sources. As opposed to existing methods, the proposed method can create this map for both synchronised and unsynchronised sound sources by taking the different localisation errors into account. We show that this gives more accurate estimates than assuming identical estimation errors, and that existing methods are outperformed in terms of estimation accuracy for various noise levels and reverberation times.

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Source Localization With Isotropic Arrays

Cited by 5 publications

References 6 publications

An Optimal Shaped Sensor Array Derivation

An Optimal Shaped Sensor Array Derivation

Optimal Array Design and Directive Sensors for Guided Waves DoA Estimation

Loudspeaker and Listening Position Estimation Using Smart Speakers

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