Active Control of Sound Radiation Pressure

Meirovitch, L.; Thangjitham, S.

doi:10.1115/1.2930118

Cited by 22 publications

(8 citation statements)

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“…For the SISO configuration, actuator P1 was used in conjunction with PVDF sensor Si as shown in Figure 2. The geometry and location of the PVDF sensor Si is such that it observes only the (1,1), (1,2) and (3,1) modes. Therefore, reduction in the radiation of these modes is observed in Figure 6.…”

Section: Results With Pvdf Error Sensorsmentioning

confidence: 99%

<title>Control of broadband radiated sound with adaptive structures</title>

1993

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Active structural acoustic control using adaptive structures has been demonstrated for harmonic disturbances. This paper presents an extension of this work to the attenuation of acoustic radiation from structures subject to broadband disturbances. An adaptive, multi-input multi-output (MIMO), feedforward broadband acoustic control system has been developed based on the least mean squares ELMS) algorithm, The compensators are adaptive finite impulse response FIR) filters. The control inputs are implemented with piezoelectric ceramic actuators. Both far-field microphones and polyvinylidene fluoride (PVDF) structural sensors designed to observe the efficient acoustic radiating modes are used as error sensors. The disturbance is band-limited zero mean white noise and is implemented with a point force shaker. In the control of hannonically excited systems, satisfactory attenuation is possible with a single-input single-output (5150) controller. In contrast, for systems excited with broadband disturbances, a MIMO controller is necessary for significant acoustic attenuation. Experimental results for the control of a simply supported plate are presented.

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Section: Results With Pvdf Error Sensorsmentioning

confidence: 99%

<title>Control of broadband radiated sound with adaptive structures</title>

1993

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“…nn Or, = I (7) Here OJ is the excitation frequency; a. is the modal number; W, is the modal amplitude; and P,, is the modal force depending on the forms of external forces.…”

Section: Lateral Vibration Of Uniform Beammentioning

confidence: 99%

“…Shakers can efficiently control the sound radiation [6][7][8] although they have substantial disadvantages due to their large volume, large weight and support requirements. Recently, the compact distributed types of actuators, such as piezoelectric patches, have been shown to be feasible for structural vibration and acoustic control [9-121. Microphones are generally used as error sensors in ASAC; however, the fact that microphones must be located in the radiated far-field makes them impractical for applications.…”

Section: Introductionmentioning

confidence: 99%

Active control of far-field sound radiation by a beam with piezoelectric control transducers: physical system analysis

Wang

1994

Smart Mater. Struct.

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This paper analytically demonstrates the use of piezoelectric actuators and PVDF sensors to actively control the far-fieid sound radiation from a simplysupported beam in an infinite rigid baffle. The beam is assumed to be subjected to a harmonic point force. The piezoelectric patches which are attached to the beam serve as actuators to control the sound radiated from the beam into the far-field, while the PVDF films serve as structural error sensors. A minimization process is used to calculate the optimal input voltages into the piezoelectric actuators so as to minimize the cost function which is the least mean square value of the error sensor signals. Radiation directivity patterns are plotted, and the wavenumber analysis is performed to evaluate the control effectiveness. Results show that the use of the compact distributed types of actuators and sensors can efficiently attenuate the far-field sound radiation. The reduction of sound pressure level for on-resonance cases is over 20-50 dB; however, little attenuation can be achieved or even spillover may occur for off-resonance cases due to the arbitrary location of actuators and sensors. This work demonstrates the use of structural actuators and near-field sensors for far-field sound radiation control and leads to the inherent application of an intelligent material structure system.

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“…Active control has been applied to the control of sound radiation from a plate 1-4 and the sound transmission into a rectangular enclosure. 5, 6 Meirovitch and Thangjitham 4 showed that more control actuators generally gives better control effects. Pan et al 6 used a point-force actuator to control sound transmission into an enclosure, and discussed the control mechanisms in terms of plate-and cavity-dominated modes.…”

Section: Introductionmentioning

confidence: 98%

Active control of harmonic sound transmission into an acoustic enclosure using both structural and acoustic actuators

Kim

Brennan

2000

The Journal of the Acoustical Society of America

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This paper describes an analytical and experimental investigation into the active control of harmonic sound transmission in a structural-acoustic coupled system. A rectangular enclosure is considered that has five acoustically rigid walls and a flexible plate on the remaining side through which a harmonic sound wave is transmitted into the enclosure. The control system is designed to globally reduce the sound field inside the enclosure, and the roles of structural and acoustic actuators are of particular interest. Three control configurations, classified by the type of actuators, are compared and discussed. They are: (i) use of a single point-force actuator, (ii) use of a single acoustic piston source, and (iii) simultaneous use of both a point-force actuator and an acoustic piston source. It is shown both analytically and experimentally that the point-force actuator is effective in controlling plate-dominated modes while the acoustic source is effective in controlling cavity-dominated modes. Since the transmitted sound field is governed by both plate- and cavity-dominated modes, the hybrid use of both types of actuators is shown to be a desirable configuration for the active control of sound transmission into a structural-acoustic coupled system.

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Active Control of Sound Radiation Pressure

Cited by 22 publications

References 0 publications

<title>Control of broadband radiated sound with adaptive structures</title>

<title>Control of broadband radiated sound with adaptive structures</title>

Active control of far-field sound radiation by a beam with piezoelectric control transducers: physical system analysis

Active control of harmonic sound transmission into an acoustic enclosure using both structural and acoustic actuators

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