System identification and energy‐based active noise control performance

2003 ◽  
Vol 114 (4) ◽  
pp. 2332-2333
Author(s):  
Benjamin M. Faber ◽  
Scott D. Sommerfeldt
Keyword(s):  
System Identification ◽  
Noise Control ◽  
Active Noise Control ◽  
Control Performance ◽  
Active Noise

Singular vector filtering method for mitigation of disturbance enhancement in multichannel active noise control systems

2021 ◽  
Vol 69 (5) ◽  
pp. 451-459
Author(s):  
Yongjie Zhuang ◽  
Xuchen Wang ◽  
Yangfan Liu
Keyword(s):  
Noise Control ◽  
Active Noise Control ◽  
Singular Values ◽  
Control Performance ◽  
Frequency Bands ◽  
Singular Vectors ◽  
Singular Value Decomposition Method ◽  
Autocorrelation Matrix ◽  
Frequency Responses ◽  
Active Noise

In the design of multichannel active noise control filters, the disturbance enhancement phenomenon will sometimes occur, i.e., the resulting sound is enhanced instead of being reduced in some frequency bands, if the control filter is designed to minimize the power of error signals in other frequency bands or across all frequencies. In previous work, a truncated singular value decomposition method was applied to the system autocorrelation matrix to mitigate the disturbance enhancement. Some small singular values and the associated singular vectors are removed, if they are responsible for unwanted disturbance enhancement in some frequency bands. However, some of these removed singular vectors may still contribute to the noise control performance in other frequency bands; thus, a direct truncation will degrade the noise control performance. In the present work, through an additional filtering process, the set of singular vectors that causes the disturbance enhancement is replaced by a set of new singular vectors whose frequency responses are attenuated in the frequency band where disturbance enhancement occurs, while the frequency responses in other frequency bands are unchanged. Compared with truncation approach, the proposed method can maintain the performance in the noise reduction bands, while mitigating the influence in disturbance enhancement bands.

Active Control of High Order Acoustical Modes in a Semi-Infinite Waveguide

1991 ◽  
Vol 113 (4) ◽  
pp. 523-531 ◽  
Author(s):  
J. D. Stell ◽  
R. J. Bernhard
Keyword(s):  
Control Systems ◽  
Active Control ◽  
Noise Control ◽  
Active Noise Control ◽  
High Order ◽  
Control Methods ◽  
Control Performance ◽  
Secondary Sources ◽  
Active Noise ◽  
New Finding

This paper presents an analysis of the effectiveness of active noise control methods for control of high order modes in rigid-walled, semi-infinite waveguides. The waveguides examined in this investigation are terminated at one end with a rigid end. The case studies performed reconfirmed that n control actuators can control n propagating modes (including the plane wave) in a waveguide if the actuators are properly placed. The results also confirmed that the control actuators should be located at the node surfaces of the most significant evanescent modes to avoid various problems that evanescent modes cause active control systems. A significant new finding is the effect of the rigid waveguide termination on the active controller. The reflected energy from the termination causes standing waves in the region between the rigid termination and the secondary sources. At certain frequencies which correspond to resonant conditions, the standing wave amplitudes become large and the control actuator strength must be high. At these frequencies the effects of the evanescent modes become significant even when the mode is not close to its cut-on frequency. Similar resonant effects can be expected to affect active noise control performance for any case where there are significant reflections in the waveguide upstream of the control actuators.

scholarly journals Active structural-acoustic control of interior noise in a vibro-acoustic cavity incorporating system identification

2017 ◽  
Vol 36 (3) ◽  
pp. 261-276 ◽  
Author(s):  
Ashok K Bagha ◽  
Subodh V Modak
Keyword(s):  
Kalman Filter ◽  
System Identification ◽  
Noise Control ◽  
Active Noise Control ◽  
State Observer ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Active Noise ◽  
Acoustic Control ◽  
Structural Acoustic Control

Linear quadratic Gaussian optimal control is one of the techniques used for active noise control. In practical implementation of this technique, one of the key difficulties faced is the estimation of the states of the plant. A state observer that accurately estimates these states can be used in this regard. Studies reported make use of analytically or experimentally derived models to build observers. This paper proposes a method for active noise control in the framework of active structural-acoustic control incorporating system identification for the development of the linear quadratic Gaussian controller. Kalman filter is used as a stochastic state observer of the plant states. System identification is carried out using modal testing and finite element model updating to obtain an accurate model of the plant for building up the Kalman filter. The objective of the proposed method is to actively reduce the noise inside the cavity due to disturbances acting on the cavity structure. The active control is achieved by controlling the structural vibrations by taking into account the degree of coupling between the various structural and the acoustic modes. The effectiveness of the proposed method is evaluated experimentally on a 3D rectangular box cavity with a flexible plate.

Noninvasive system identification for multichannel broadband active noise control

2000 ◽  
Vol 107 (4) ◽  
pp. 2049-2060 ◽  
Author(s):  
William C. Nowlin ◽  
Gary S. Guthart ◽  
Gregory K. Toth
Keyword(s):  
System Identification ◽  
Noise Control ◽  
Active Noise Control ◽  
Active Noise
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