Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
A comparative analysis of online and offline methods for secondary path estimation in active noise control applications using the Fx-LMS algorithm
Submission Author:
Bruno Giuliani Gomes , DF
Co-Authors:
Bruno Giuliani Gomes, Gabriela Cristina Candido da Silva, Renato Lopes, Maria Alzira de Araújo Nunes, André Murilo
Presenter: Bruno Giuliani Gomes
doi://10.26678/ABCM.COBEM2023.COB2023-0512
Abstract
The proliferation of HVAC (Heating, Ventilation, and Air Conditioning) systems in our homes, industry, and daily lives has led to a growing problem of acoustic noise pollution. Passive and active noise control methods have been developed to address this issue. Active noise control (ANC) is an effective technique that uses control algorithms and destructive interference principles to attenuate noise that is difficult and expensive to control using passive methods. The Filtered-x Least-Mean Square (Fx-LMS) algorithm is a widely used ANC model that requires a secondary path model to estimate the sound filtering process between the control speaker and its reference microphone. Secondary path estimation can be performed using either online or offline methods. Online methods estimate the parameters in real-time during system operation, while offline methods estimate the model parameters beforehand or afterward using input/output data. This paper presents experimental results for the Fx-LMS algorithm with online and offline secondary path estimation methods in an acoustic duct. The experimental setup involves a tubular duct with a primary speaker at one end and an open end. The primary speaker generates the noise to be controlled, while the control speaker for generating the anti-noise is placed at an intermediate location on the tube. Two microphones measure the reference signal, and another monitor the signal error and the controller’s performance. The ANC algorithm is implemented on a dSpace dS1104 platform. The study compares the control algorithm’s complexity, computational cost, and performance for both an online and an offline method. The results provide quantitative and qualitative information about the strengths and weaknesses of the different designs, which can help identify the best approach for each application depending on specific requirements.
Keywords
Secondary Path, Online and Offline estimation, Acoustic Duct, Fx-LMS, Active noise control
