Near field acoustic holography (NAH) theory for cyclostationary sound field and its application

Wan, Qin; Jiang, Weikang

doi:10.1016/j.jsv.2005.05.002

Cited by 18 publications

(14 citation statements)

References 14 publications

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“…After three working statuses (normal, pitting and partial broken tooth) are simulated in this way, the array measurement is applied to sample signals. A linear array consisted of 17 microphones are used [14] as depicted in figure 1, in which other 5 microphones are used as references. The distances of two adjacent elements on the linear array are 50 mm.…”

Section: Sampling Of Acoustic Signalsmentioning

confidence: 99%

Research on Diagnosing the Gearbox Faults Based on Near Field Acoustic Holography

Jiang

Hou

Xing

2011

J. Phys.: Conf. Ser.

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Abstract. The gearbox fault diagnosis was developed for some decades. The current diagnosis techniques were mostly based on analyzing the shell vibration signals especially close to the bearing seat of gearbox. In order to utilize the spatial distribution information of fault signal, the near field acoustic holography (NAH) is employed for the condition monitoring and fault diagnosis of the gearbox in this presentation. The distribution images of sound pressure on the surface of gearbox are reconstructed by NAH, and the feature extraction and pattern recognition can be made by image processing techniques. A gearbox is studied in a semi-anechoic chamber to verify the fault diagnosis technique based on NAH. The pitting and partial broken tooth faults of gears are artificially made on one gear as the fault statuses, and the differences of acoustic images among normal and fault working states under the idling condition are analyzed. It can be found that the acoustic images of gearbox in the three different situations change regularly, and the main sound sources can be recognized from the acoustic images which also contain rich diagnosis information. After feature extraction of the acoustic images, the pattern reorganization technique is employed for diagnosis. The results indicate that this diagnosis procedure based on acoustic images is available and feasible for the gearbox fault diagnosis.

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Section: Sampling Of Acoustic Signalsmentioning

confidence: 99%

Research on Diagnosing the Gearbox Faults Based on Near Field Acoustic Holography

Jiang

Hou

Xing

2011

J. Phys.: Conf. Ser.

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“…Signals are sampled in 6times. The influence of time-delay in the signal sampling in the experiment can be removedaccording to the time-delay property of CSD [10]. The analysis frequencyisselected as f = 62 Hz in the unique cyclic frequency400 Hz.…”

Section: Speaker Experimentsmentioning

confidence: 99%

“…To gain the modulating characteristics in the cyclostationary sound field, ak ind of NAHm ethod named cyclostaionary near-field acoustic holography( CYNAH) wasd eveloped to reconstruct the CSD instead of the PSD or spectrum reconstructed by the conventional NAH [10,11]. In the present work, the CYNAH method is accommodated to arbitrarily shaped sources which are closer to the practical ones in the engineering.…”

Section: Introductionmentioning

confidence: 99%

The Application of Wave Superposition Algorithm to Identify Cyclostationary Sound Source

Zhang¹,

Jiang²,

Wan³

et al. 2008

Acta Acustica united with Acustica

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The cyclostationary characteristics can not be extracted clearly in reconstruction of the acoustic field radiated from the cyclostationary sources by the conventional near-field acoustic holographyp rocedures. The cyclostationary near-field acoustic holographym ethod uses the cyclic spectrum density function as the reconstruction variance instead of the spectrum or the power spectrum density,which decomposes the carrier wave and modulating wave in the appropriate cyclic frequency. The reconstructed CSD shows the distribution of the modulating wave of cyclostationary sources and supplies more cyclostationary acoustical information than the conventional NAH. In the present work, the theory of the cyclostationary NAHcombined with the wave superposition is introduced, which can be used for the arbitrarily shaped cyclostationary sources. Anumerical simulation and aspeaker experiment are employed to validate this WSA-based cyclostationay NAHmethod. The results of the simulation showg reat agreement between the reconstruction and the analytical value. The distribution of the CSD of the cyclostationary acoustical source on the surface coincides with the speaker box accurately.

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“…Zhao X., et al [5] reconstructed the vibro-acoustic fields generated by an arbitrary structure vibrating in an unbounded fluid medium. Wan Quan, et al [6] proposed the cyclostationary near-field acoustic holography with a view to overcome the limitations of the traditional near-field acoustic holography. In the late 80's of the last century, Loyau and Pascal proposed broadband acoustic holography based on sound intensity measurement (BAHIM) .…”

Section: Introductionmentioning

confidence: 99%

Exterior noise prediction of light duty truck based on near-field acoustic holography

Chen

Wang

Zuo

et al. 2010

2010 International Conference on Mechanical and Electrical Technology

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The basic principle of broadband acoustic holography based on intensity measurement (BAHIM) is demonstrated. Numerical simulation is made with point source as object, and reconstruction phase of the complex sound pressure is exactly obtained. The light duty truck manufactured by some Chinese auto manufacturer was tested with BAH 1M, the radiated sound field of the noise source is forecasted, the far-field noise forecast is validated by intensity measurement experimentation, and the exterior noise source of the truck is identified. The result of the exterior noise test demonstrates that RAHIM is an effective method of noise source identification and forecast.

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Near field acoustic holography (NAH) theory for cyclostationary sound field and its application

Cited by 18 publications

References 14 publications

Research on Diagnosing the Gearbox Faults Based on Near Field Acoustic Holography

Research on Diagnosing the Gearbox Faults Based on Near Field Acoustic Holography

The Application of Wave Superposition Algorithm to Identify Cyclostationary Sound Source

Exterior noise prediction of light duty truck based on near-field acoustic holography

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