• Title/Summary/Keyword: Filtered-x LMS algorithm

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An Adaptive System Improving Robustness for Active Noise Control (강인성을 개선한 적응능동소음제어 시스템)

  • Shin, Seung-Sik;Jeong, Yang-Woong;Koo, Choon-Keun;Lee, Sang-Cheol;Chung, Chan-Soo
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.993-995
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    • 1996
  • This paper proposes an adaptive Filtered-X LMS algorithm with robustness. The proposed system updates filter parameters to keep the performance even if the conventional Active Noise Control (ANC) system well does not work. As a result of the computer simulation, the proposed system has all the advantage of the system using the conventional Filtered-X LMS algorithm. Also some results from the proposed algorithm present that the system is stable when the Adaptive filter does not work. Therefore, the proposed system using the Adaptive Filtered-X LMS algorithm must have much advantage than the system using the conventional algorithm in the side of the stability and performance.

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Active Vibration Control of Acoustically Loaded Flexible Plate Enclosure Using Multi-Channel Control Algorithm (다채널 제어알고리듬을 이용한 음향 가진된 밀폐계 평판의 능동진동제어)

  • Hong, Jin-Seok;Park, Su-Hong;Kim, Heung-Seop;O, Jae-Eung;Jeong, Jin-Tae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.6 s.177
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    • pp.1390-1397
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    • 2000
  • This paper presents the multi-channel active vibration control of a flexible plate of the acoustically loaded enclosure. The flexible plate was excited acoustically with sinusoidal and white noise input. The control was performed by two piezo ceramic actuators and two accelerometers. The experimental results were compared with the single channel control results. In the case of white noise input, 20 dB of vibration reduction was achieved below 300Hz frequency range. The experimental results demonstrate that multi-channel filtered-x LMS algorithm is effective than single-channel filtered-x LMS algorithm in active vibration control of plate.

A Study on the Characteristics of Applicability in the Active Noise Cancellation System and Measurement of the Road Noise for Traffic Calming (교통환경 정온화를 위한 도로 소음의 측정 및 ANC시스템에의 적용 특성 고찰)

  • Moon, Hak-Ryong;Shon, Jin-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.62 no.3
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    • pp.111-116
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    • 2013
  • Noise problem that occurs on the road is raising a lot of problems in the economic, social and environmental aspects. The objective of this paper is to propose ANC(active noise cancellation)-based road traffic noise reduction algorithm-model which can reduce noise by generating frequency opposed to noise sources to improve and complement the problem that existing physical form of a noise barrier. In this paper, we measured the noise characteristic from collection of two difference car noise also ANC simulation has been performed by using road traffic noises input. In order to compare the control performance, we performed noise reduction simulation of ANC by filtered-X LMS algorithm and delayed control signal injection. As a result of this simulation, we confirmed that convergence performance and noise decrease effect to the filtered-X LMS algorithm by inputting the road traffic noise.

Active vibration control of a flexible cantilever beam using Filtered-x LMS algorithm (Filtered-x LMS 알고리즘을 이용한 유연한 외팔보의 능동진동제어)

  • 박수홍;홍진석;김흥섭;오재응
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.107-113
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    • 1997
  • This paper presents the active control of a flexible cantilever beam vibration. The cantilever beam was excitied by a steady-state harmonic and white noise point force and the control was performed by one piezo ceramic actuator bonded to the surface of the beam. An adaptive controller based on filtered-x LMS algorithm was used and the controller was defined by minimizing the square of the response of error sensor. In the experiment, gap sensor was used as an error sensor while the sinusoidal or white noise was applied as a disturbance. In the case of sinusoidal input, more than 20 dB of vibration reduction was achieved over all range of the natural frequencies and it takes 5 seconds to control the vibration at first natural frequency and 1 second at other natural frequencies. In the case of white noise input, 7 dB of vibration reduction was achieved at the first natural frequency and good control performance was achieved in the considered whole frequency range. Results indicate that the vibration of a flexible cantilever beam could be controlled effectively when the piezo ceramic actuator was used with filtered-x LMS algorithm.

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A study of defects of filtered-X LMS algorithm for modeling error (모델링오차에 따른 Filtered-X LMS 알고리즘의 오동작에 관한 고찰)

  • Park Byoung-Uk;Ko Byeong-Seob;Kim Hack-Yoon
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.359-362
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    • 2000
  • ANC시스템에 있어서 현재 많이 이용되고있는 Filtered-X LMS 알고리즘에서 2차 음원과 제어점간의 임펄스응답은, 미리 동정하여 사용하는 것이 일반적이지만, 2차 음원과 제어점간의 전달특성이 이후에 변화할 경우, 실제의 전달함수와 적응에 이용한 전달함수간에 모델링 오차가 발생하게된다. 이 모델링 오차에 의하여 알고리즘은 오동작을 일으키고, 시스템은 불안정하게 되기도 한다. 따라서, 본 연구에서는 참조신호가 랜덤신호일 경우에 발생하는 모델링 오차와 Filtered-X LMS 알고리즘의 오동작에 관한 이론식을 도출하고, 시뮬레이션을 통하여 이를 입증하였다.

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Active Control of Road-Booming-Noise with Constraint Multiple Filtered-X LMS Algorithm

  • Oh, Shi-Hwan;Kim, Hyoun-Suk;Park, Young-Jin
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.2E
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    • pp.3-7
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    • 2000
  • Vibration generated by the non-uniform road profile propagates though each tire and the suspension and finally generates structure born noise in the interior of the passenger vehicle. In this paper, the road-booming-noise which has strong correlation with the vibration signals measured at the suspension system was compensated. Active noise control of the road-booming-noise is rather difficult to achieve because of its non-stationary characteristics. CMFX LMS (Constraint Multiple Filtered-X Least Mean Square) algorithm, which can track non-stationary process rather well, is applied. Comprison of the proposed method and the conventional MFX LMS (Multiple Filtered-X Least Mean Square) algorithm is made through the hardware-in-the-loop simulation and the feasibility of the proposed method is demonstrated with the experiment.

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Acceleration Feedforward Control in Active Magnetic Bearing System Subject to Base Motion by Filtered-x LMS Algorithm (베이스 가진을 받는 능동자기베어링 시스템에서 Filtered-x LMS 알고리듬을 이용한 가속도 앞먹임 제어)

  • Kang, Min-Sig
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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    • pp.1712-1719
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    • 2003
  • This paper concerns on application of active magnetic bearing(AMB) system to levitate the elevation axis of an electro-optical sight mounted on moving vehicles. In such a system, it is desirable to retain the elevation axis within the predetermined air-gap while the vehicle is moving. An optimal base acceleration feedforward control is proposed to reduce the base motion response. In the consideration of the uncertainty of the system model, a filtered-x least-mean-square(FXLMS) algorithm is used to estimate the frequency response function of the feedforward control which cancels base motions. The frequency response function is fitted to an optimal feedforward control. Experimental results demonstrate that the proposed control reduces the air-gap deviation to 27.7% that by feedback control alone.

Development of Active Intake Noise Control Algorithm for Improvement Control Performance under Rapid Acceleration and Disturbance (L-Point Running Average Filter를 이용한 급가속 흡기계의 능동소음제어 성능향상을 위한 알고리즘 개발)

  • 전기원;조용구;오재응;이정윤
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.780-783
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    • 2004
  • Recently Intake noise has been extensively studied to reduce the engine noise. In order to diminish intake noise several resonators were added to the intake system. However this can cause a reduction of engine output power and an increase of fuel consumption. In this study, active noise control simulation of the Filtered-x LMS algorithm is applied real instrumentation intake noise data under rapid acceleration because intake noise is more excessively increased under the such a harsh condition. But the FXLMS algorithm has poor control performance when the system is disturbed. Thus modified FXLMS algorithm using L-point running average filter is developed to improve the control performance under the rapid acceleration and disturbance. The noise reduction quantity of modified Filtered-x LMS algorithm is more than original one in two cases. In the case of control for real instrumentation intake noise data, maximum residual noise of modified FXLMS algorithm is 2.5 times less than applied the FXLMS and also in the case of disturbed, the modified FXLMS algorithm shows excellent control performance but FXLMS algorithm cat not control.

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Active Noise Control of the Plane Wave Travelling in a Duct Using Filtered-x LMS Algorithm (Filtered-x LMS 알고리즘을 응용한 덕트내 평면파 소음의 능동제어)

  • 우재학;김인수;이정권;김광준
    • Journal of KSNVE
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    • v.2 no.2
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    • pp.107-116
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    • 1992
  • An adaptive signal processing technique is implemented for the active noise cancellation of the plane acoustic wave propagating in a duct. To avoid the instability caused by the acoustic feedback from the control speaker to the detect microphone, an off-line modeling of the acoustic feedback plant is done using the FIR filter. Auxiliary path required for the filtered-x LMS algorithm is modeled as well. Before going into the experiments, a simulation is carried out under the same conditions with experiments. The simulation shows that the longer the length of the adaptive filter is, the better the results are achieved. Experiments have been carried out at lower audio frequency range (50 - 400Hz), and the results are in good agreements with those of simulation study. As a results of this adaptive noise control, around 50dB is reduced for a pure tone noise, and for a bandlimited noise with the bandwidth of 316Hz, a maximum of 30dB noise reduction is attained.

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The Study on the Performance Improvement and the Development of Active Intake Noise Control System (능동홉기소음제어 시스템의 개발 및 성능향상에 관한 연구)

  • 이충휘;오재응;심현진;이유엽
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.326-329
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    • 2002
  • Engine noise is one of the major causes of the interior noise, and so has been studied in various ways in recent days. Recently Intake 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. In this study, the prototype of Active Intake Noise Control System is developed by using the Filtered-x LMS algorithm to reduce the Intake noise during acceleration. Intake noise is more excessively increased when the engine is rapidly accelerated. So, Normalized LMS algorithm is applied to improve the control performance under the rapid acceleration.

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