Multiple channel active noise control system based on simultaneous equations methods

For complicated noise fields, a multiple channel active noise control (ANC) system with several secondary sources, error sensors, and reference sensors is required. A multiple error filtered-X (MEFX) algorithm is developed for an adaptive algorithm in the multiple channel ANC system. This algorithm requires a previous estimation of the error paths. However, the characteristics of the error paths should be assumed to change during the operation of the system. This paper proposes a control algorithm for the multiple channel ANC system without the previous estimation of the error paths. This algorithm becomes an extension of the simultaneous equations method proposed for the single channel ANC system. In the proposed method, the good performances for noise cancellation and tracking of the changes in the error paths are achieved.