MicrodB is participating in the sound radar experiment of the French Ministry of Ecological Transition

MicrodB is participating in the sound radar experiment of the French Ministry of Ecological Transition. After two years of development for the development of the methodology and the production of prototypes, the first dBFlash sound radar system was installed at the start of 2022 in the Haute Vallée de Chevreuse, France. Two other installations will follow in the cities of Bron and Paris.

Some visitors have already seen the system installed in our parking lot in Vibratec since last June. The track tests organized by CEREMA and Gustave Eiffel University made it possible to “verify the correct operation of the three devices (is the noise emitted by a moving vehicle correctly detected and assigned to the correct vehicle?), …”. In addition, MicrodB carried out track tests at Transpolis which made it possible to test the system on more complex scenarios.

MicrodB would like to thank FoxStream, Centum Adeneo, the LVA laboratory, the Auvergne Rhône Alpes region through the dBCatch project, but also ADEME for the 2019 winner in the innovation competition with the dBFlash project, contributing to the development of this first prototype.

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MicrodB publication in the Journal of the Acoustic Society of America

underwater deconvolution test configuration

Example of a fruitful collaboration between French R&D labs & organizations and innovation companies, the paper entitled “Multiplane deconvolution in underwater acoustics: Simultaneous estimations of source level and position was published earlier this month in the Express Letters section of the JASA.

Presenting an original CLEAN deconvolution procedure to achieve simultaneous location, source level estimation & de-noising, the paper shares part of the results of the FUI 22 collaborative project “Abysound,” funded by the Pôle Mer Méditerranée and the French Banque Publique d’Investissement (BPI).

The publication’s starting point was the realization that conventional beamforming cannot provide both accurate position and source level estimates simultaneously. The new deconvolution approach is illustrated using experimental data mimicking a challenging deep-sea mining configuration: an underwater acoustic source of interest located 700 m below the sea surface, tens of meters from a 3 m-diamater array, with boat noise as the disturbing source.

The Abysound project implicated Naval Group, OSEAN SAS, MicrodB, Semantic TS, l’Institut Français de Recherche pour l’Exploitation de la Mer (IFREMER), Gipsa-Lab, the Laboratoire de Mécanique & d’Acoustique (LMA), and the Laboratoire des Sciences de l’Information & des Systèmes (LSIS). Work was performed within the framework of the LABEX CeLyA (ANR-10-LABX-0060) of Université de Lyon, within the program Investissements d’Avenir (ANR-16-IDEX-0005) operated by the French National Research Agency (ANR).


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Acoustical characterization of an e-motor using 3D imagery

The technical achievement is the acoustical characterization of an e-motor in run-up conditions. The directivity of the sources around the motor has been deeply studied.

The iterative Bayesian Focusing method combined with refined acoustical transfer functions has been industrially applied. Confidence intervals about the sound power have been also estimated.

This paper has been supported by the national project FUI LUG2.  This study has been extracted from a larger study made with Renault. The measurements were carried out on the VibraTec test bench.

BeBeC Berlin 2nd and 3rd of March 2020

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MirodB presents its work on underwater acoustic source localization at Oceans 2019

To answer sound disturbance issues due to deep sea underwater mining prospecting, MicrodB studies the possibility to set up an underwater acoustic source localization and quantification monitoring system in deep water (700 m).

After a first simulation step to point out the best acoustic array geometry for this problem, it was built and then tested in shallow water in 2018. Results presented at Oceans 2019 show the agreement between simulation and experimental data validating the whole conception of this array.

This work was realized within the framework of FUI 22 Abysound project, funded by Pôle Méditerranée and Banque Publique d’Investissement whose partners are Naval Group, OSEAN SAS, Semantic TS, Ifremer, Gipsa-Lab, LMA and LSIS.

To discover more about this project or MicrodB actions in underwater acoustics, don’t hesitate to come to the OCEANS 2019 conference or contact us !

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Transmission loss measurement of an automotive dashboard by imaging techniques

Based on multi-arrays measurement, the Bayesian Focusing has been applied to measure the Transmission Loss (TL) on a 3D mesh representing the real geometry of an automotive Dashboard.

New Bayesian priors have been tested to enforce the spatial sparsity of the sound sources. As the sources are stationary in the frequency domain, a spatial prior defined on a large range of frequencies has been applied.

The work has been done with Trèves Group.

This research was supported by the LUG2 project funded by the Région Auvergne Rhône-Alpes and the BPI France (grant FUI22).

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Industrial applications for the Bayesian sound source localization approach

sound source localization

Sound source localization using microphone arrays is largely applied in industrial engineering to diagnose acoustic issues appearing in complex machines. Over the past 30 years, a large number of methods have been developed to improve the source identification procedure.

Bayesian Focusing can generalize these methods by automatically calculating the optimal functions based on the geometrical set-up. In addition, probabilistic acoustic inverse problem solving offers the possibility to introduce prior knowledge of the source, noise and propagation model.

MicrodB is a precursor in this technology thanks to its collaboration with the INSA Lyon

The use of Bayesian Focusing capabilities to extract source characteristics (directivity, coherence, sound power) greatly improves sound source identification in industrial applications.

This will be documented at the ISMA conference in Leuven on September 17th to 19th.

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Bayesian focalisation applied to wind tunnels – AIAA/CEAS conference Atlanta

Between 25th and 29th June 2018 will be held the 24th AIAA/CEAS Aeroacoustics Conference in Atlanta.

It is certainly one of the most famous scientific conferences in the field of flow induced acoustics. MicrodB is proudly contributing to a research paper, together with Ecole Centrale de Lyon, University of Sherbrooke and Safran Aircraft Engines. The work, entitled ‘Broadband Airfoil-Noise Source Localization by Microphone Arrays and Modeling of a Swept Free-Tip Blade’ will be presented by Gyuzel Yakhina.

It is the occasion to apply advanced microphone array techniques in complex wind tunnel configurations.

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LUG2 project at NOVEM 2018


MicrodB, INSA Lyon and CNRS will present a paper entitled « SENSITIVITY ANALYSIS OF ACOUSTIC INVERSE PROBLEMS » at NOVEM 2018 Ibiza from 7th to the 9th May

The characterisation of an acoustic source is achieved by retro-propagating the acoustic field measured with a microphone array to a mesh of the surface of interest. This latter step is performed by solving an inverse problem. Such inverse problems are built on the basis of a forward model prone to uncertainties arising from the physics of the experiment.

Assessing the effects of these uncertainties on the resolution of the inverse problem represents a challenge. This paper introduces a practical solution to measure these effects by conducting a sensitivity analysis. The sensitivity analysis method applied here provides a mean to identify and rank the main sources of uncertainty through the estimation of sensitivity indices. Two inverse methods are investigated for the reconstruction of a monopole source: Beamforming and Bayesian focusing. The propagation of uncertainties is carried on numerically. The consistency between the real experiment and its numerical approximation is assessed by means of a small batch of measurements performed in a semi-anechoic chamber.

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Managing MEMs microphone calibration – MicrodB will share its findings at the 14th French Acoustic Congress in Le Havre from April 23rd to 27th

Array calibration

MicrodB will take advantage of the French Acoustic Congress in Le Havre to present its work on local MEMs microphone calibration and the integration of an associated filter to correct its response.

The democratization of information technologies and communication (ICTS) offers new possibilities for acoustic metrology, and more specifically methods implicating a large number of microphones. Digital MEMs sensors and embedded ARM FPGA processors provide a new solution for these situations, increasing performance while reducing implementation costs.

However, the integration of these technologies, which are not intended for metrology, requires rigorous calibration to identify and correct the intrinsic frequency response of the MEMs welded on an electronic board (PCB).

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Come and meet Vibratec at TRA 2018

Transportation network

If you are interested in meeting Vibratec at TRA 2018 in Vienna, the 17th and 18th of April, Lucille LAMOTTE will participate in the oral presentations and bilateral meetings organized in parallel by ETNA2020 Transport Networking and Brokerage Event focusing on the Horizon H2020 ‘Smart green and integrated Transport’ calls 2018-2020.

As an SME used to working on R&D projects on both national and international levels, we know the importance of finding the right partners for each project. ETNA is the perfect opportunity to broaden our network and increase visibility for potential European partners.

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