628 A Noise Barrier Using Active Noise Control Technique

Wang, Xnn; Kijimoto, Shinya; Koba, Yosuke

doi:10.1299/jsmedmc.2011._628-1_

Cited by 3 publications

(3 citation statements)

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“…Feedback (FB) ANC system requires only one error sensor to perform control so that a compact controller can be implemented, and as it does not require the advanced noise source signal in the control, it can be used to reduce the noise from the either side of the partition. According to these two features, a compact ANB, which exploits an FB-ANC system placed on the top edge of the partition to reduce the sound diffraction , has been proposed in the previous work (4). However, the FB control can only reduce the narrow band noise, and the waterbed effect (5) of the FB control will cause noise amplification out of the control bandwidth.…”

Section: Introductionmentioning

confidence: 99%

Active reduction of the two-way diffraction from a noise barrier by using feedforward control

Shudo

Wang

Koba

et al. 2018

The Proceedings of Conference of Kyushu Branch

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This paper develops a feedforward (FF) structure based active noise control (ANC) system that reduces the two-way diffraction from an office partition with the aim of actively creating isolated acoustic domains in open-plan offices. The FF-ANC system can only reduce the noise downstream of the reference sensor due to the causality requirement. Therefore, a coupled FF control structure is proposed to realize the reduction of two-way diffraction. This system applies a two-source loudspeaker array as the control source, and two microphones as the reference and error sensors. The directivity of the loudspeaker array is controlled to emit the control sound only into the corresponding control area. In comparison with the preceding active diffraction reducing systems, using a directivity controlled loudspeaker array can generate an absorptive acoustic boundary rather than a reflective boundary on the diffracting edge, which can isolate the acoustic environment without adding reverberation in a room. The effectiveness of the proposed system is verified by computer simulations.

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Section: Introductionmentioning

confidence: 99%

Active reduction of the two-way diffraction from a noise barrier by using feedforward control

Shudo

Wang

Koba

et al. 2018

The Proceedings of Conference of Kyushu Branch

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“…(Hothersall, et al, 1991) (Ishizuka and Fujiwara, 2004) (May and Osman, 1980) (Samuels and Ancich, 2001) (Ishizuka and Fujiwara, 2004) (Active noise control, ANC) (Elliott, 2001) (Kuo and Morgan, 1996) ANC (Active noise barrier, ANB) (Ise, et al, 1991(Ise, et al, ) ( 2007 (Kijimoto, et al, 2009) ( 2012a) (Wang, et al, 2011) ( 2014) ANC (Ise, et al, 1991(Ise, et al, ) ( 2007 ( 2001) (Wang, et al, 2011) (Kijimoto, et al, 2009 FB-ANC ANB FB-ANC FB (Freudenberg and Looze, 1985) (Skogestad and Postlethwaite, 2005) ANB FB-ANC …”

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confidence: 99%

Noise barrier using hybrid ANC system (Supression of the noise enhancement caused by the waterbed effect and investigation of the noise attenuation performace under various sound field configurations)

Wang

Koba

Ishikawa

et al. 2015

Transactions of the JSME (In Japanese)

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Noise barrier using hybrid ANC system (Supression of the noise enhancement caused by the waterbed effect and investigation of the noise attenuation performace under various sound field configurations) AbstractIn this paper, the hybrid active noise control (HB-ANC) system applied in the active noise barrier (ANB) is improved, and the noise attenuation performace of the ANB is invetigated under four different sound field configurations. This hybird ANB reduces the diffraction noise from top of the ANB and the noise propagated to the head position of the target person behind the ANB simultaneously to achieve higher noise attenuation. However, the waterbed effect of the feedback control part of the HB-ANC system will cause noise enhancement at some frequencies in the control area. In order to solve this problem, the HB-ANC system is improved by adding a filter to cancel the noise enhancement caused by the waterbed effect. Then, the noise attenuation performance of the hybrid ANB under four sound field configurations is evaluated by simulations. The sound field configurations are set up to investigate how the diffraction from side of the ANB and the reflection influence the performance of the ANB. An experiment in the anechoic chamber is also conducted. The results indicate that the low frequency noise attenuation can be obtained in a wide area behind the ANB, and at the head position of the person, the noise attenuation can be ensured within a wider frequency range, even for the sound fields where the uncontrolled diffraction from side and the reflection exist.

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“…Other alternative arrangements consider the secondary sources in the receiver zone [78,79] or include the secondary sources and error microphones vertically along with the receiver side of the barrier [80], giving these configurations generally poor results, although only one position was tested in each case. But, in general terms, the new design of secondary sources [81], practical applications [82], or theoretical studies of the cancellation mechanisms [83] place secondary sources or error microphones at the top of the barrier.…”

Section: Introductionmentioning

confidence: 99%

Active control of noise transmitted from barriers

Sohrabi

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Active noise cancellation is a unique approach that helps passive noise control in reducing sound levels at low frequencies; nevertheless, successful use of active noise cancellation necessitates performing numerous and tedious experiments together with defining several parameters properly. The locations and quantity of active control system transducers are among these parameters. The present research provides a comprehensive framework for placing control sources and error microphones near a noise barrier in order to improve its efficiency in both narrowband and broadband noise spectra. To accomplish this, the appropriate locations for the control sources are first determined using a repetitive computation method, and then the optimizations are completed by determining the best position for the error microphone. Several alternative transducer locations near the barrier are incorporated in the repetitive computation, and the optimal sites for the control sources and error microphones are found using two-step optimization methods as well as the genetic algorithms approach. The findings reveal that the best places to put the control sources are on the incident side, below the barrier's edge, and the best locations to place the error microphones are on the shadow side, as close as possible to the target area. The effect of ground reflection on the efficiency of the active noise control system is also investigated, and it is discovered that while ground reflection has no significant effect on the performance of the active noise control system for broadband frequency ranges, it does reduce the control system's efficiency at tonal noises. In order to optimize more parameters, further calculations are performed based on the genetic optimizer. The output of the GA calculations found new configurations for the control units that result in higher noise level reduction at the target area. In addition to the active noise barrier, the application of active noise cancellation for open windows as a particular case of the barrier is explored as a particular case of the barrier. Different arrangements are studied for the control units close to the open windows, including linear, boundary, and planar control arrangements. The effect of several parameters such as the incident angle of noise waves, the distance between error microphones and the opening, and the number of control units are investigated. The results demonstrate that the active noise control system with obliqued linear placements of transducers have higher performance than the other arrangements. Furthermore, when the frequency and incident angle increase, the effectiveness of active noise reduction decreases. La cancelación activa de ruido es un enfoque único que ayuda al control pasivo del ruido a reducir los niveles de sonido a bajas frecuencias; sin embargo, el uso exitoso de la cancelación activa de ruido requiere la realización de numerosos y tediosos experimentos junto con la definición adecuada de varios parámetros. La ubicación y la cantidad de transductores del sistema de control activo se encuentran entre estos parámetros. La presente investigación proporciona un marco completo para colocar fuentes de control y micrófonos de error cerca de una barrera de ruido con el fin de mejorar su eficiencia en espectros de ruido de banda estrecha y banda ancha. Para lograr esto, primero se determinan las ubicaciones apropiadas para las fuentes de control usando un método de cálculo repetitivo, y luego se completan las optimizaciones determinando la mejor posición para el micrófono de error. Varias ubicaciones de transductores alternativas cerca de la barrera se incorporan en el cálculo repetitivo, y los sitios óptimos para las fuentes de control y los micrófonos de error se encuentran utilizando métodos de optimización de dos pasos, así como el enfoque de algoritmos genéticos. Los hallazgos revelan que los mejores lugares para colocar las fuentes de control están en el lado del incidente, debajo del borde de la barrera, y los mejores lugares para colocar los micrófonos de error están en el lado de la sombra, lo más cerca posible del área objetivo. También se investiga el efecto de la reflexión del suelo sobre la eficiencia del sistema de control de ruido activo, y se descubre que si bien la reflexión del suelo no tiene un efecto significativo en el rendimiento del sistema de control de ruido activo para rangos de frecuencia de banda ancha, sí reduce el rendimiento del sistema de control. eficiencia en ruidos tonales. Para optimizar más parámetros, se realizan más cálculos basadosen el optimizador genético. El resultado de los cálculos de GA encontró nuevas configuraciones para las unidades de control que dan como resultado una mayor reducción del nivel de ruido en el área objetivo. Además de la barrera de ruido activa, se explora la aplicación de la cancelación de ruido activa para ventanas abiertas como un caso particular de la barrera. Se estudian cuatro disposiciones para las unidades de control cercanas a las ventanas abiertas. Las unidades de control en una configuración de límite se colocan en el borde de la abertura, mientras que en el control plano, se ubican en la superficie de la abertura. En una configuración de contorno, las unidades de control se colocan en el borde de la abertura, mientras que en un diseño plano, se colocan en la superficie de la abertura. Se investiga el efecto de varios parámetros como el ángulo de incidencia de las ondas de ruido, la distancia entre los micrófonos de error y la apertura, y el número de unidades de control. Los resultados demuestran que el sistema de control de ruido activo con configuración plana tiene un rendimiento más alto que el control de límites. Además, cuando la frecuencia y el ángulo de incidencia aumentan, la eficacia de la reducción activa del ruido disminuye.

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628 A Noise Barrier Using Active Noise Control Technique

Cited by 3 publications

References 0 publications

Active reduction of the two-way diffraction from a noise barrier by using feedforward control

Active reduction of the two-way diffraction from a noise barrier by using feedforward control

Noise barrier using hybrid ANC system (Supression of the noise enhancement caused by the waterbed effect and investigation of the noise attenuation performace under various sound field configurations)

Active control of noise transmitted from barriers

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