Numerical simulation of acoustic holography with propagator adaptation

Martin, Vincent; Bourdon, Thibault Le; Pasqual, Alexander Mattioli

doi:10.1016/j.jsv.2011.03.029

Cited by 8 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was tempting to assume that the regularization modified the model in order to reduce ψ . The observation countered this assumption and we demonstrate below in four steps the independence of angle ψ from the coefficient ε with the consequence that the effect of regularization cannot be described easily in the objective space (Martin and Le Bourdon, 2010), perhaps a natural conclusion in retrospect since % E is not acted upon, contrarily to its "inverse"…”

Section: Error Of the Objective And Of The Modelmentioning

confidence: 81%

See 1 more Smart Citation

The fundamental elements in certain inverse acoustic problems: their roles and interactions

Martin

2012

J. Braz. Soc. Mech. Sci. & Eng.

Self Cite

View full text Add to dashboard Cite

Acoustic holography and holophony, wave field synthesis and active noise control are based on common elements which are causality, model, objective, and regularization. In the frequency domain (putting causality aside), a simple formulation states the influence-not the interaction-of errors of the model and objective and of regularization of the results. However, it does not give either an understanding or any relation of cause to effect. When the objective can be reached using the available model, regularization is not needed and the information liable to be extracted from this determined problem is poor, unlike in the overdetermined case when the model does not allow the objective to be reached. The geometrical interpretation of the over-determined problem written in the least-mean square sense could be a tool to enlighten the influences and interactions in question. After having shown the interest of the geometrical interpretation, a pseudo-analytical inverse problem in spherical holophony and a numerical problem in plane holography provide particular illustrations. From among the properties accessible, one is highlighted: in the case of a perfect objective but inaccurate model, its adaptation brings a decrease in the amount of regularization required and an improvement in the results.

show abstract

Section: Error Of the Objective And Of The Modelmentioning

confidence: 81%

“…In Martin, Le Bourdon and Pasqual (2011), a thick vibrating disc (Fig. 14) radiates sound in the unbounded 3D space.…”

Section: Numerical Nearfield Holographymentioning

confidence: 99%

The fundamental elements in certain inverse acoustic problems: their roles and interactions

Martin

2012

J. Braz. Soc. Mech. Sci. & Eng.

Self Cite

View full text Add to dashboard Cite

show abstract

“…1 For acoustic inverse reconstruction problems, particle velocity-based near-field acoustical holography, proved to yield better reconstruction quality than the conventional pressure-based methods. 2,3 Recently, a hybrid array containing pressure and velocity sensors was implemented using maximum likelihood estimation for direction of arrival 4 problems. In the emerging field of spatial audio reproduction, wave field synthesis renders a spatial sound field by approximating the Kirchhoff-Helmholtz integral equation, which requires an array of pressure and velocity sensors in the recording stage.…”

Section: Introductionmentioning

confidence: 99%

Particle velocity estimation based on a two-microphone array and Kalman filter

Bai

Juan

Chen

2013

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

A traditional method to measure particle velocity is based on the finite difference (FD) approximation of pressure gradient by using a pair of well matched pressure microphones. This approach is known to be sensitive to sensor noise and mismatch. Recently, a double hot-wire sensor termed Microflown became available in light of micro-electro-mechanical system technology. This sensor eliminates the robustness issue of the conventional FD-based methods. In this paper, an alternative two-microphone approach termed the u-sensor is developed from the perspective of robust adaptive filtering. With two ordinary microphones, the proposed u-sensor does not require novel fabrication technology. In the method, plane wave and spherical wave models are employed in the formulation of a Kalman filter with process and measurement noise taken into account. Both numerical and experimental investigations were undertaken to validate the proposed u-sensor technique. The results have shown that the proposed approach attained better performance than the FD method, and comparable performance to a Microflown sensor.

show abstract

“…Sound field reconstruction using microphone arrays has emerged as a useful tool for noise source identification by visualizing sound fields radiated by noise sources. [1][2][3] Microphone array techniques fall into two categories: Near-field acoustical holography (NAH) 4,5 and far-field beamforming. 6,7 Planar Fourier NAH was introduced in the 1980s by Williams and Maynard.…”

Section: Introductionmentioning

confidence: 99%

Optimal two-layer directive microphone array with application in near-field acoustical holography

Bai

Wang

Juan

2012

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Conventional near-field acoustical holography (NAH) is generally based on the free-field assumption, which can cause errors when interfering sources are present in practical environments. To cope with this problem, previous research suggested a combined pressure-velocity approach for NAH that provides certain advantages to rejection of interferences. This paper revisits this idea in a broader context of optimal array design and examines the feasibility of using unidirectional microphones in each channel of the array such that the robustness of inverse reconstruction is enhanced against interfering sources. As indicated in the simulation, the numerical noise in finite difference estimation of particle velocity can nullify the advantage of the well-conditioned velocity-based reconstruction. In the proposed approach, the characteristics of each array channel consisting of two microphones are tailored by taking into account not only the directivity, but also the robustness against self-noise. An objective function based on directivity index and white noise gain is exploited in a linear quadratic optimization of a two-element end-fire array. The proposed optimal array is validated in conjunction with the equivalent source model (ESM) -based NAH through numerical simulations, with an interfering source positioned behind the array. The results have shown the directive optimal array has yielded improved quality of images in comparison with conventional approaches in the presence of an interfering source and sensor noise.

show abstract

Numerical simulation of acoustic holography with propagator adaptation

Cited by 8 publications

References 17 publications

The fundamental elements in certain inverse acoustic problems: their roles and interactions

The fundamental elements in certain inverse acoustic problems: their roles and interactions

Particle velocity estimation based on a two-microphone array and Kalman filter

Optimal two-layer directive microphone array with application in near-field acoustical holography

Contact Info

Product

Resources

About