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Author: search.filters.author.Sookpuwong, ChadapornHas files: No

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    ANC System Modeling and Simulations in a Wide-Area Virtual Environment Using FDTD Approach with Perfectly Matched Layer Absorbing Boundaries
    (2021-12-01)
    Sookpuwong, Chadaporn
    ;
    Chompoo-inwai, Chow
    This paper presents a model and simulation results of the active noise control (ANC) system in a wide-area virtual environment using the acoustics finite-difference time-domain (FDTD) propagation approach defined by particle velocities and sound pressure level (SPL) within a certain absorbing boundary conditions called a perfectlymatched layer (PML) technique. The ANC excitation applies a single-frequency noise source with an adaptive feedforward configuration. The FDTD algorithm is used to model the area of interest acoustically, including a desired quiet zone, considering the effects from a primary path, a secondary path, and a feedback path. A processing unit of the ANC system based on the least mean-squared (LMS) algorithm is utilized to synthesize a cancelling noise using a secondary loudspeaker. A single-channel feedforward ANC system used in this paper is modified from the proposed multi-channel models and forms. Acoustics FDTD propagation results can be used to determine the optimum placements for ANC sensors and actuators. The SPL numerical and graphical results are plotted to demonstrate the performance of the proposed ANC system. All of the simulation results confirm that the proposed modeling approach can be combined with wide-area acoustic simulations and a feedforward LMS adaptive algorithm. The proposed model also provides a way for the optimum placement of the ANC sensors and actuators before being used in a more-complex practical environment
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    A multi-channel feedforward ANC system using a novel FXLMS algorithm in solving classroom aviation-noise problems
    (2019-11-01)
    Sookpuwong, Chadaporn
    ;
    Chompoo-inwai, Chow
    Adaptive or Active Noise Control (ANC) system is now widely used in many applications. In this paper, a novel multi-channel feedforward ANC system is presented to lower the level of the aviation noises which occurred in the KMITL University's classrooms. A system is simulated in MATLAB/Simulink environment. The proposed multichannel feedforward ANC system configurations including related equations are described in this paper. The modified Filtered-X Least-Mean-Square (FXLMS) method is used for updating the weight vector in ANC control block diagram in order to achieve the optimal weight vector resulting in minimal errors. How to find bounds on the step size and how to estimate the rate of convergence as well as the steady-state errors of the proposed system with FXLMS algorithm are also elaborated. The secondary-path effects are considered and compensated in this research. The simulation results are presented in terms of noise attenuation capabilities and the Mean-Square-Error (MSE) convergence time. Simulation results and conclusions presented in this paper will be used for further analysis to improve the system performance of the proposed ANC methodology before implementing in the actual classroom.
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    A Multi-Channel Feedforward ANC with FXLMS Algorithm for Aviation-Noise Suppression
    (2019-11-01)
    Sookpuwong, Chadaporn
    ;
    Chompoo-Inwai, Chow
    This paper presents a novel multi-channel feedforward Active Noise Control (ANC) system using Filter-x Lease Mean Square (FXLMS) algorithm for reducing classroom-aviation noises. Such a system will be simulated in MATLAB for a demonstrative classroom in KMITL University, Bangkok, Thailand. This circumstance becomes an interesting issue since the aforementioned classroom is located right next to one of the Asia Pacific's largest international airport namely Bangkok Suvarnabhumi International Airport. An aviation noise problem occurs when aircrafts taking off and landing. The main idea of this research is trying to lower the level of the aviation noises which occurred in the classroom. A novel multichannel feedforward ANC system has been brought into account here. The FXLMS algorithm is used for updating the ANC controller coefficient in order to achieve the optimal weight vector resulting in minimal errors. A conceptual design of a proposed ANC and system configurations including all related equations are described. The simulation results will be presented in terms of noise attenuation capabilities and the Mean Square Error (MSE) convergence time. Simulation results presented in this paper will be used for further analysis to improve the system performance of the proposed ANC methodology before implementing in the real classroom.
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    Performance comparisons between a single-channel feedforward anc system and a single- channel feedback anc system in a noisy-enviroment classroom
    (2017-10-27)
    Sookpuwong, Chadaporn
    ;
    Chompoo-Inwai, Chow
    Adaptive or Active Noise Control System (ANC) is now widely used in many applications. The problem of interference or noise cancellation is one of the main focuses of the ANC solutions. In this paper, two classic ANC systems called a single-channel feedforward system and a single-channel feedback system will be simulated in MATLAB/Simulink environment for a demonstrative university classroom. This circumstance becomes an interesting issue since the aforementioned classroom is located right next to one of Asia Pacific's largest international airport in Bangkok City, Thailand. A very lousy-noise environment occurs when the time of airplane taking off and landing. Unfortunately, such a noisy environment happens almost every other minute on average. The main idea of this paper is trying to lower the level of the noise during those critical times in the classroom. Two simple ANC systems are brought into account here to see how they perform in resolving the problems in this particular circumstance. The least mean square (LMS) method is used for updating the weight vector in ANC control block diagram in order to achieve the optimal weight vector resulting in minimal errors. How to find bounds on the step size, how to estimate the rate of convergence and the steady-state errors of the proposed LMS method are also elaborated in this paper. The simulation results between two ANC systems will be presented in terms of noise attenuation capabilities and system performances. The discussions and the conclusions presented in this research paper will be used for further analysis to improve the selected ANC system performance before implementing in the real environment in a very near future to come.