scholarly journals Multichannel Feedforward Active Noise Control System with Optimal Reference Microphone SelectorBased on Time Difference of Arrival

2018 ◽  
Vol 8 (11) ◽  
pp. 2291 ◽  
Author(s):  
Kenta Iwai ◽  
Satoru Hase ◽  
Yoshinobu Kajikawa

In this paper, we propose a multichannel active noise control (ANC) system with an optimal reference microphone selector based on the time difference of arrival (TDOA). A multichannel feedforward ANC system using upstream reference signals can reduce various noises such as broadband noise by arranging reference microphones close to noise sources. However, the noise reduction performance of an ANC system degrades when the noise environment changes, such as the arrival direction. This is because some reference microphones do not satisfy the causality constraint that the unwanted noise propagates to the control point faster than the anti-noise used to cancel the unwanted noise. To solve this problem, we propose a multichannel ANC system with an optimal reference microphone selector. This selector chooses the reference microphones that satisfy the causality constraint based on the TDOA. Some experimental results demonstrate that the proposed system can choose the optimal reference microphones and effectively reduce unwanted acoustic noise.

1989 ◽  
Vol 111 (3) ◽  
pp. 337-342 ◽  
Author(s):  
R. J. Silcox ◽  
H. C. Lester ◽  
S. B. Abler

This paper examines the physical mechanisms governing the use of active noise control in an extended volume of a cylindrical shell. Measured data were compared with computed results from a previously derived analytical model based on infinite shell theory. For both the analytical model and experiment, the radiation of external monopoles is coupled to the internal acoustic field through the radial displacement of the thin, elastic, cylindrical shell. An active noise control system was implemented inside the cylinder using a fixed array of discrete monopole sources, all of which lie in the plane of the exterior noise sources. Good agreement between measurement and prediction was obtained for both internal pressure response and overall noise reduction. Attenuations in the source plane greater than 15 dB were recorded along with a uniformly quieted noise environment over an indicative length inside the experimental model. Results indicate that for forced responses with extended axial distributions, axial arrays of control sources may be required. Finally, the Nyquist criteria for the number of azimuthal control sources is shown to provide for effective control over the full cylinder cross section.


2019 ◽  
Vol 18 (04) ◽  
pp. 1930002 ◽  
Author(s):  
Hsiao Mun Lee ◽  
Zhaomeng Wang ◽  
Kian Meng Lim ◽  
Heow Pueh Lee

Active noise control (ANC), with counteracting sound in exact equal magnitude and opposite phase to the noise to be controlled, is often considered as a potential solution for solving complex noise problems. However, there are both myths and challenges in its implementations. In a crowded city like Singapore, many noise sources from construction site and subway track are located very close to the residential and commercial buildings. It was suggested by few researchers that by placing suitable control speakers at the construction site (working principle of ANC), the noise from the construction site could be prevented from propagating to the surrounding buildings. Similarly, for viaduct or subway track, by placing control speakers along the viaduct or track, the noise generated by the passing trains or vehicles could be reduced based on the principle of ANC technique. However, implementation of ANC technique on these noise issues is not easy as all of these noise control problems involve multiple noise sources with complex or transient frequency spectrum in large three-dimensional/open space. Therefore, the main intention of the present paper is to discuss the current state of the art of this topic as well as to examine the potential application and limitation of the ANC technique in mitigating unwanted noise, particularly in large three-dimensional/open space and with cooperation of passive noise barrier.


2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
Govind Kannan ◽  
Issa M. S. Panahi ◽  
Richard W. Briggs

A large class of acoustic noise sources has an underlying periodic process that generates a periodic noise component, and thus their acoustic noise can in general be modeled as the sum of a periodic signal and a randomly fluctuating signal (usually a broadband background noise). Active control of periodic noise (i.e., for a mixture of sinusoids) is more effective than that of random noise. For mixtures of sinusoids in a background broadband random noise, conventional FXLMS-based single filter method does not reach the maximum achievable Noise Attenuation Level (NALmax⁡). In this paper, an alternative approach is taken and the idea of a parallel active noise control (ANC) architecture for cancelling mixtures of periodic and random signals is presented. The proposed ANC system separates the noise into periodic and random components and generates corresponding antinoises via separate noise cancelling filters, and tends to reach NALmax⁡ consistently. The derivation of NALmax⁡ is presented. Both the separation and noise cancellation are based on adaptive filtering. Experimental results verify the analytical development by showing superior performance of the proposed method, over the single-filter approach, for several cases of sinusoids in white noise.


1997 ◽  
Vol 16 (2) ◽  
pp. 109-144 ◽  
Author(s):  
M.O. Tokhi ◽  
R. Wood

This paper presents the development of a neuro-adaptive active noise control (ANC) system. Multi-layered perceptron neural networks with a backpropagation learning algorithm are considered in both the modelling and control contexts. The capabilities of the neural network in modelling dynamical systems are investigated. A feedforward ANC structure is considered for optimum cancellation of broadband noise in a three-dimensional propagation medium. An on-line adaptation and training mechanism allowing a neural network architecture to characterise the optimal controller within the ANC system is developed. The neuro-adaptive ANC algorithm thus developed is implemented within a free-field environment and simulation results verifying its performance are presented and discussed.


2010 ◽  
Vol 13 (3) ◽  
pp. 67-74
Author(s):  
Tuan Van Huynh ◽  
Nghĩa Hoai Duong

The principle of active noise control (ANC) is to produce a secondary acoustic noise which has the same magnitude as the unwanted primary noise but with opposite phase. The sum of these two signals reduces acoustic noise in the noise control area. In this paper we present a new ANC method using neural system. Moreover a new method for compensating the saturation of the power applifier is also introduced. The performance of the proposed method is compared to that of traditional methods. Simulation results are provided for illustration.


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