Feasibility of the full-rank fixed-filter approach in the active control of noise through open windows

摘要

Successful implementation of active noise control (ANC) systems is dependent on their practicality. ANC systems that attenuate environmental noise through open windows of urban accommodation should ideally avoid the use of error microphones for the ease of implementation and maintenance. To remove the error microphones, control filters can be fixed by formulating a steady-state equation for various incidences of noise. The trade-off of such a fixed-filter approach, however, is the degradation in noise attenuation performance when the incident noise deviates from the incidence angles used to formulate the fixed filter. Using a multichannel control formulation of tonal disturbances, a fixed-filter formulation is compared with the exact least squares solution in a 2D window finite element method (FEM) simulation. Preliminary results have showed that the full-rank fixed-filter approach can theoretically yield the same attenuation as the exact least-squares method in cases of single incidence and multiple noise incidences, with some exceptions.