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1

Double Panel Structure for Active Control of Noise Transmission

Morzyński L., Szczepański G.

Archives of Acoustics

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2018

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Vol. 43, No. 4

689--696

EN

Passive noise reduction means are commonly used to reduce noise in the industry but, unfortunately, their effectiveness is poor in the low frequency range. By applying active structural acoustic control to the enclosure walls significant improvement of the insulating properties in this frequency range can be achieved. In this paper a model of double panel structure with ASAC is presented. The structure consists of two aluminium plates separated by an air gap. Two inertial magnetoelectric actuators and two piezoceramic MFC sensors were used for controlling the structure. A multichannel FxLMS algorithm with virtual error microphone technique is used as a control algorithm. The signal of a virtual error microphone is extrapolated basing on signals from MFC sensors. Performance of this actively controlled structure for tonal signals at selected frequencies is presented in the article. During the study, a double panel structure was mounted on one wall of sound insulating enclosure located in an acoustic chamber. During the measurements local and global reduction of noise test signal was investigated.

2

Dwupłytowa struktura aktywna do ograniczania transmisji hałasu przez obudowy i przegrody dźwiękoizolacyjne

Morzyński L., Krukowicz T.

Bezpieczeństwo Pracy : nauka i praktyka

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2017

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nr 10

24-28

PL

Obudowy dźwiękoizolacyjne są jednym i podstawowych środków technicznych, stosowanych powszechnie do ograniczania hałasu. Izolacyjność przegród pasywnych maleje jednak ze spadkiem częstotliwości dźwięku. Izolacyjność w zakresie niskich częstotliwości może być zwiększona poprzez zastosowanie aktywnych metod redukcji hałasu. W artykule przedstawiono budowę i zasadę działania dwupłytowej struktury aktywnej do ograniczania transmisji hałasu przez przegrody. Do sterowania przegrodą korzystano algorytm z ekstrapolacją sygnału błędu w oparciu o sygnały z przetworników drganiowych Przedstawiono wyniki badań struktury na stanowisku laboratoryjnym.

EN

Sound insulating enclosures are a basic technical measure commonly used to reduce noise. Insulation of passive sound insulating barriers, however, decreases with a decrease in frequency. Insulation in the low frequency range can be increased by using active noise control methods. This article presents the structure and principle of operation of a double-layered active structure to limit the transmission of noise through barriers. An algorithm, which extrapolates the error microphone signal based on signals from the vibration transducers, is used for structure control. This article presents structure performance in laboratory conditions.

3

A two-stage Wiener filter based multi-channel feedback virtual microphone acoustic noise reducing system

Pawełczyk M.

Archives of Acoustics

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2007

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Vol. 32, No. 4

917--922

EN

An optimal fixed-parameter control system capable to generate zones of quiet at a number of desired locations is designed and analysed in this paper. Although it is of feedback structure the design problem is reformulated so that theWiener filter approach can be applied. Polynomial technique is used. Due to non-minimum phase character of the plant including delays it requires performing the inner-outer factorization of a polynomial matrix and the causal-anticausal decomposition. For this control system two stages of operation can be distinguished. Experimental verification confirms that the zones of quiet are correctly distributed. Moreover, the control system remains stable for significant changes of the plant.