Active control for periodic noise wih variable fundamental. An extended DXHS algorithm with frequency tracking ability.

Abstract

In our daily life, there are many kinds of noise. Some of them are periodic, such as exhaust noise of an engine and fan noise, and numerous methods have been proposed to control the periodic noise. Most methods need a reference signal, and the reference signal must be measured or known in advance. In actual environment, the frequency of the periodicnoise is not always time invariant. When active noise control systems are implemented, the information on a periodic noise can be obtained by an external sensor like tachometer. Therefore the performance of an active noise control system depends on the accuracy of the external sensor. In this paper, two adaptive algorithms able to control a periodicnoise are proposed. One algorithm estimates fundamental frequency, amplitude and phase of a periodic noise. Another algorithm estimates each frequency comprised in a periodicnoise independently. The performance of these algorithms is evaluated by computer simulations and in the experiment using a duct.