• 제목/요약/키워드: Filtered-x LMS Algorithm

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Duct ANC 시스템에서 2차음원 방향별 소음감소효과 (An attenuation effect of noise according to the direction of secondary sound source in duct ANC system)

  • 이형석;이응석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.497-502
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    • 2008
  • In this paper, we studied on an attenuation effect of automobile exhaust noise according to the direction of secondary sound source in duct ANC system. Automobile exhaust noise was recorded at 800rpm. 3500rpm and 5000rpm of a diesel engine. Directions of loudspeaker(second sound source) can be exchanged to $30^{\circ}$, $90^{\circ}$ and $150^{\circ}$ against the primary noise flow by acrylic ducts to be made for experimentation. DSP board with TMS320C6416 chip of Texas Instrument Co used to control adaptive ANC system. This ANC system is based on the single-channel FxLMS algorithm. In experiment result, when the loud speaker direction was $150^{\circ}$, the attenuation effect showed largely. In case of $90^{\circ}$ duct, the noise was a little increased. In case of $30^{\circ}$ duct, the noise was a little increased or decreased according to the frequency range and the sound pressure(dB) of exhaust noise to comply with engine rpm.

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FXLMS 알고리즘을 이용한 전력용 변압기의 능동소음제어에 관한 연구 (A study on the Active Noise Control for Power Transformer using FXLMS Algorithm)

  • 박우용;김선대;김영달
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.207-210
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    • 2008
  • 변압기에서 발생하는 소음은 근무자의 작업환경을 열악케 하는 직접적인 요인이 될 뿐만 아니라 정신적인 스트레스를 받게 되어 작업능률 저하 및 변전소 인접 주민들의 일상생활 환경을 저해하는 요인이 되고 있다. 본 연구에서는 이러한 문제점을 개선하기 위하여 FXAMS 알고리즘을 적용한 변압기의 능동소음제어에 대한 연구를 수행하였으며, 다중음 다채널 제어가 가능한 시스템을 개발하여 현장에 적용한 결과, 120Hz에서는 9.06[dB]의 능동소음감쇄가 이루어졌으며, 전체적으로 4.55[dB]의 감쇄효과가 얻을 수 있었다.

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능동제어기법을 이용한 흡기계의 소음 저감에 관한 연구 (The Study on the sound reduction of Intake System using Active Control Method)

  • 이충휘;홍진석;오재응;김영식;박동철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.165-168
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    • 2000
  • Engine noise is one of the major causes of the interior noise, and so has been studied in various ways in recent days. Recently air induction noise has been extensively studied to reduce the engine noise. Conventional method to reduce the noise is adding several resonators to the induction system. However this causes a reduction of engine output power and an increase of fuel consumption. Thus in this study, the feasibility of applying the active noise control to the induction system is studied to the overcome the above disadvantage.

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제어오차계의 가중치를 이용한 차실내 능동소음제어 시스템 연구 (A Study on the Active Noise Cancellation System in a Vehicle Cabin Using the Weighting Factors of Control Error Path)

  • 홍석윤;허현무
    • 소음진동
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    • 제6권6호
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    • pp.851-856
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    • 1996
  • The active noise cancellation system showing the effective convergence and stability has been studied by simplifying the controller structures using the weighting factors of control error path to the multi-channel filtered-x LMS algorithm which needs a lot of calculations and the performance has been verified experimentally. Besides, to implement the system performance in a vehicle cabin, experimental work for selecting the suitable numbers and positions of the microphones and speakers was accomplished. Effectively combining a TMS 320C 31 main processor conducting real number calculations and having various functions with other components, the purpose-built system board for active noise cancellation has been designed and with this board, car active noise cancellation system showing maximum stable 10dB noise reduction has been obtained at the car idling conditions above 3000rpm range.

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유연구조물이 있는 다점지지 시스템의 능동진동제어 (Active vibration control of multi-point mounting systems with flexible structures)

  • 오시환;박영진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.274-279
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    • 2000
  • Driving of the engine makes unbalance forces which induces vibration to the engine mount system. Active vibration control must be performed to reduce the vibration and the propagation of structure-born sound. In this study, the engine system is modeled as 3-dim. vibration system including flexible structures and an effective active noise control method is proposed. Also, appropriate actuator and sensor locations and types are selected. The miniature of the engine vibration system with multi-input multi-output is built and an active vibration control with multiple filtered-X LMS algorithm is applied to it. The applied control method was effective to reduce the transmitted vibration power through the rubber mount It showed the feasibility of the control of the engine vibration systems with flexible structures.

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향상된 온라인 모델링 방법을 이용한 능동 소음 제어 시스템 (Active noise control system using modified on-line secondary path modeling method)

  • 박병욱;최태호;김학윤
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.2200-2203
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    • 2003
  • In an active noise control(ANC) system using the Filtered-X least mean square(LMS) algorithm, the online secondary path modeling method by exploiting a random noise generator is applied. This method is suitable for secondary path modeling. However, it is increased the residual error of the ANC system. In this paper, we presents an ANC system improved online secondary path modeling method which is modified Kuo and Zhang model that is the secondary path estimation by the additive noise. In addition, our proposed model is used that additive noise is transformed into the signal multiplied reference signal by gain control parameter and delayed.

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Active Control for Outdoor Noise using an FXLMS Approach

  • ;김동일;이영섭
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2011년도 추계학술대회 논문집
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    • pp.672-672
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    • 2011
  • This study describes the comparison of noise suppression performances at different locations of two error microphones in active noise control (ANC) for outdoor applications. For this study, 12 different locations were predefined to decide best locations for error sensors in terms of suppressing noise. As shown in Fig. 1, the ANC system with one primary loudspeaker, two secondary loudspeakers and two error microphones is operated by a filtered-x LMS (FXLMS) algorithm which is implemented in a TI 6713 DSP board and Realsys 4713 AD/DA Extension board. The noise for the primary source is a typical road noise measured at a highway roadside. The lengths of adaptive filters of W1 and W2 are varied from 32 to 128 respectively. An intensive computer simulation was accomplished before outdoor ANC experiments. It is expected from the simulation results that the ANC performances are very much dependent upon the locations of the two error microphones.

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적응 선형 증진기를 이용한 인버스 모델링의 성능향상 (Performance Improvement of the Inverse Modeling using Adaptive Line Enhancer)

  • 김흥섭;홍진석;손동구;신준;오재응
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.267-271
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    • 1996
  • In this study, performance improvement of the inverse modeling as the on-line control method for the estimation, control experiment is performed. As the modeling errors is occurred in duct system arbitrarily, a case using the filtered-x LMS algorithm only as the control method, a case using tile inverse modeling method only and a case using the inverse modeling with the adaptive line enhancer are compared. The estimation errors between real secondary path transfer functions and the estimated and the control performances of primary noises with these estimated transfer functions are compared.

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지능제어 방식에 의한 밀폐계 평판의 능동진동제어 (Active Vibration Control of the Enclosed Plate by Intelligent Control Method)

  • 신준;이태연
    • 한국공작기계학회논문집
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    • 제14권4호
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    • pp.55-60
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    • 2005
  • In this study, vibration control of the enclosed plate which is typical two dimensional structure are performed by using intelligent control method and piezo ceramic as an actuator attached at the plate. The characteristics of the plate with piezo ceramic are examined to identify the natural frequencies. Then, the plate is controlled under the sinusoidal excitation by acoustic source and the reduction level of vibration is examined via frequency response and time sequence. The control result shows the effect of the intelligent control method as a control scheme compared with that of the previous filtered-X LMS algorithm.

덕트 소음 제거를 위한 하이l브리드형 능동 소음제어기의 설계. (Design of a Hybrid Active Noise Controller for Duct Noise)

  • 홍석기;안동준;남현도
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 B
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    • pp.1307-1309
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    • 1996
  • This paper presents hybrid active noise control (HANC) systems which is based on the combination of feedforward and feedback ANC controllers. HANC systems use FIR filters and is based on primary noise regeneration principle and filtered-X LMS algorithms. HANC systems show better attenuation characteristics and residual spectrum. The order of adaptive filters used in HANC systems is lower than that of conventional feedforward and feedback ANC systems. A proposed HANC algorithm was implemented using a Taxas Instruments TMS320C31 digital signal processor for experimental verification.

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