zou09-COLLOQUE

With the widespread use of the passenger cars in people´s daily life, the requirement to the noise environment inside the car is becoming stricter and stricter. For most cars, the engine-related periodic noise is the dominant part of the internal noise. A multiple channel narrowband feedforward active noise control system using a modified Filtered-X Least Mean Squares (FXLMS) algorithm has been developed and installed in a passenger car to reduce the low-frequency noise components. After a brief introduction to the set-up of the ANC system, the algorithm development and implementation will be presented in detail. In practice, the performance of the ANC system will be affected mainly by the accuracy of the plant estimate, the convergence speed, and also the robustness of the ANC algorithm. During the first experiments, the practical ANC system has already been proven to some extent to be effective to attenuate the periodic noise, specifically the 2nd order engine harmonic. However, because of the complexity of acoustic environment inside the car and the frequency dependent convergence behavior of the algorithm, more work need to be focused on the optimization of plant estimate and the ANC algorithm to improve the performance of the ANC system in the future study.