• Title/Summary/Keyword: Active noise controller

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Active Vibration Control of Smart Hull Structure Using MFC Actuators (MFC 작동기를 이용한 스마트 Hull 구조물의 능동 진동 제어)

  • Sohn, Jung-Woo;Kim, Heung-Soo;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.217-222
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    • 2005
  • Active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuator is performed. Finite element modeling is used to obtain governing equations of motion and boundary effects of end-capped smart hull structure. Equivalent interdigitated electrode model is developed to obtain piezoelectric couplings of MFC actuator. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure, and compared to the results of experimental investigation. MFC actuators are attached where the maximum control performance can be obtained. Active controller based on Linear Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller and structural vibration is controlled effectively.

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Vibration Suppression of Smart Structures Using a Combined PPF-SRF Control Technique (PPF와 SRF 조합기법을 사용한 지능구조물의 능동진동제어)

  • 곽문규;라완규;윤광준
    • Journal of KSNVE
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    • v.7 no.5
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    • pp.811-817
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    • 1997
  • This paper is concerned with the active vibration controller design for the grid structure based on the positive position feedback (PPF) and the strain rate feedback (SRF) control. A new control methodology by the combination of the PPF and SRF control can suppress all the modes of the structure theoretically and can be easily implemented with analog circuits. The underlying concept for the design of the new controller is that the SRF controller stabilizes the modes higher than the second mode and the PPF controller stabilizes the fundamental mode which is destabilized by the SRF controller. In order for the new controller to be implemented succesfully, the collocated control is necessary. To this end, the piezoceramic sensor and actuator are located as close as possible, thus realizing the nearly collocated control. The combined PPF and ARF controller proves its effectiveness by experiments.

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Experimental Study on Stability of Robust Saturation Controller (강인 포화 제어기의 안정성에 관한 실험적 연구)

  • Lim, Chae-Wook;Moon, Seok-Jun;Park, Youngjin;Park, Yun-Sik
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.2 s.107
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    • pp.207-213
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    • 2006
  • In our previous research, we proposed a robust saturation controller which involves both control input saturation and structured real parameter uncertainties. This controller can analytically prescribed the upper and lower bounds of parameter uncertainties, and guarantee the closed-loop robust stability of the system in the presence of actuator's saturation. And the availability and the effectiveness of the proposed robust saturation controller were verified through numerical simulations. In this paper, we verify the robust stability of this controller through experimental tests. Expecially, we show unstable cases of other controllers in comparison with this controller. Experimental tests are carried out in the laboratory using a two-story test structure with a hydraulic-type active mass damper.

Experimental Verification on Stability of Robust Saturation Controller (강인 포화 제어기의 안정성에 관한 실험적 검증)

  • Lim, Chae-Wook;Moon, Seok-Jun;Park, Young-Jin;Park, Youn-Sik
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.223-226
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    • 2005
  • In previous research, we proposed robust saturation controller which involves both actuator's saturation and structured real parameter uncertainties. This controller can analytically prescribed the upper and lower bounds of parameter uncertainties, and guarantee the closed-loop robust stability of the system in the presence of actuator's saturation. And the availability and the effectiveness of the proposed robust saturation controller were verified through numerical simulations. In this paper, we verify the robust stability of this controller through experimental tests. Especially, we show unstable cases of other controllers in comparison with this controller. Experimental tests are carried out in the laboratory using a two-story test structure with a hydraulic-type active mass damper.

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Active Control of Transmitted Noise through Opening of Enclosures Surrounding a Noise Source (음원을 둘러싼 인클로저 개구부를 통해 투과되는 소음의 능동 제어)

  • Lee, Hanwool;Hong, Chinsuk;Jeong, Weuibong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.796-802
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    • 2013
  • In this study, we investigates active control technology to reduce the noise transmitted to the outside through the opening of enclosures. A numerical model based on acoustic boundary element method is first established. Using the numerical model, the acoustic transfer functions of the field points over the opening to the primary source at arbitrary locations are estimated. The feedforward control to minimize the acoustic power through the opening is then numerically implemented. The controller generates the secondary source to destructively interfere the noise transmission through the opening. Finally, a parametric study is conducted to evaluate the effects of the location and the number of the microphones on the control performance. Furthermore, the effects of the location of the secondary source on the performance of active noise control are investigated. It is followed that the control system implemented in this study leads to a significant reduction of about 35dB in sound power through the open using only on secondary source located at the optimized position.

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Comparison of the Multiple PPF Control and the Modified LQG Control for the Active Vibration Suppression of Intelligent Structures (지능구조물의 능동진동제어를 위한 다중 PPF 제어기와 수정 LQG 제어기의 비교 연구)

  • 곽문규
    • Journal of KSNVE
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    • v.8 no.6
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    • pp.1121-1129
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    • 1998
  • This research is concerned with the multiple PPF and the modified LQG controller design for active vibration control of intelligent structures. The intelligent structure is defined as the structure equipped with smart actuators and sensors. Various control techniques aimed for the piezoceramic sensors and actuators have been proposed for the active vibration control of smart structures and some of them prove their effectiveness experimentally. In this paper, the multiple PPF controller and the modified LQG controller are developed and applied to the smart grid structure. The multiple PPF control and the modified LQG control can be classified as the classical and the modern control techniques. respectively. The experimental results show that both control techniques are effective in suppressing vibrations. Two control techniques are compared with respect to the design process. the ease of implementation and the effectiveness

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Design of Multi-Input Multi-Output Positive Position feedback Controller based on Block-Inverse Technique (블록 역행렬 기법에 의한 다중입출력 양변위 되먹임제어기의 설계)

  • Kwak, Moon-K.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.508-514
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    • 2005
  • This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi input and multi output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments..

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Design of Multi-input Multi-output Positive Position Feedback Controller Based on Block-inverse Technique (블록 역행렬 기법에 의한 다중입출력 양변위 되먹임제어기의 설계)

  • Kwak, Moon K.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.9 s.102
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    • pp.1037-1044
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    • 2005
  • This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi-input and multi-output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block-inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments.

TWO TYPES OF ACTIVE NOISE CONTROL SYSTEM USING MFB LOUDSPEAKER

  • Nishimura, Yoshitaka;Shimada, Yasuyuki;Usagawa, Tsuyoshi;Ebata, Masanao
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1994.06a
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    • pp.764-769
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    • 1994
  • The impedance of an electro-acoustic transducer can be controlled by motional feedback, and the noise in a duct can be reduced actively by adjusting the impedance using an additional sound. In this paper, two approaches for active noise control using motional feedback (MFB) loudspeaker are described. First configuration uses an external sensor to pickup of source directly. In this configuration, the adaptation of controller is necessary to compensate the change of transfer function from noise source to control poing. The second configuration uses a new adaptive algorithm specialized for peridic noise. Because this configuration does not require any reference input and the error sensor couples very tightly with control loudspeaker, this MFB system itself is independent of the duct condition. No microphone are required in both configurations, so that a more reliable and stable active control system can be realized under severe conditions such as high pressure, high temperature, dust, flow and so on.

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Feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity

  • Bagha, Ashok K.;Modak, Subodh V.
    • Smart Structures and Systems
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    • v.20 no.3
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    • pp.273-283
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    • 2017
  • This paper presents and compares three feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity. These are a) control strategy based on direct output feedback (DOFB) b) control strategy based on linear quadratic regulator (LQR) to reduce structural vibrations and c) LQR control strategy with a weighting scheme based on structural-acoustic coupling coefficients. The first two strategies are indirect control strategies in which noise reduction is achieved through active vibration control (AVC), termed as AVC-DOFB and AVC-LQR respectively. The third direct strategy is based on active structural-acoustic control (ASAC). This strategy is an LQR based optimal control strategy in which the coupling between the various structural and the acoustic modes is used to design the controller. The strategy is termed as ASAC-LQR. A numerical model of a 3-D rectangular box cavity with a flexible plate (glued with piezoelectric patches) and with other five surfaces treated rigid is developed using finite element (FE) method. A single pair of collocated piezoelectric patches is used for sensing the vibrations and applying control forces on the structure. A comparison of frequency response function (FRF) of structural nodal acceleration, acoustic nodal pressure, and piezoelectric actuation voltage is carried out. It is found that the AVC-DOFB control strategy gives equal importance to all the modes. The AVC-LQR control strategy tries to consume the control effort to damp all the structural modes. It is seen that the ASAC-LQR control strategy utilizes the control effort more intelligently by adding higher damping to those structural modes that matter more for reducing the interior noise.