Virtual microphone sensing through vibro-acoustic modelling and Kalman filtering

• Published in: Mechanical systems and signal processing Vol. 104; pp. 120 - 133
• Main Authors: van de Walle, A., Naets, F., Desmet, W.
• Format: Journal Article
• Language: English
• Published: Berlin Elsevier Ltd 01.05.2018; Elsevier BV
• Subjects: Acoustic coupling; Acoustics; Algorithms; Computer simulation; Filtration; Finite element method; Kalman filtering; Kalman filters; Measurement; Methodology; Microphones; Model accuracy; Model reduction; Physical properties; Reduced order filters; Reduced order models; Sound; State estimation; Vibration; Vibro-acoustics; Vibro-acoustics; State estimation; Kalman filtering
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2017.08.032

•Virtual microphone approach allows full sound field measurement.•Kalman filter combines a limited set of measurements with finite element models.•Model reduction enables real-time performance.•Experimental validation demonstrates practical performance. This work proposes a virtual microphone methodology which enables full field acoustic measurements for vibro-acoustic systems. The methodology employs a Kalman filtering framework in order to combine a reduced high-fidelity vibro-acoustic model with a structural excitation measurement and small set of real microphone measurements on the system under investigation. By employing model order reduction techniques, a high order finite element model can be converted in a much smaller model which preserves the desired accuracy and maintains the main physical properties of the original model. Due to the low order of the reduced-order model, it can be effectively employed in a Kalman filter. The proposed methodology is validated experimentally on a strongly coupled vibro-acoustic system. The virtual sensor vastly improves the accuracy with respect to regular forward simulation. The virtual sensor also allows to recreate the full sound field of the system, which is very difficult/impossible to do through classical measurements.