Active Noise Control for Two-dimensional Acoustic Space by a Concentrated Mass Model

Abstract

We herein propose a new model-based control method, in place of traditional adaptive control, for low-frequency noise problem in a closed space. The proposed control method in based on state feedback control and a model of the acoustic space obtained by the concentrated mass model. According to the concentrated mass model, the acoustic space is modeled as masses, connecting linear springs, connecting dampers, and base support dampers. Furthermore, a loudspeaker, as a control source, is also modeled by a mass, a spring, and a damper. In the present paper, we constructed a coupled analysis model of a two-dimensional acoustic space and the loudspeaker. We designed the model-based system for the standing sound wave in the low-frequency band. Modal reduction using modal analysis is conducted to reduce the computation time of the controller. Then, we conducted experiments and a numerical simulation of the two-dimensional acoustic space to confirm the validity of the analysis model. Moreover, we perform an experiment to control the noise.