Abstract
Noise control is a research topic that has been widely concerned for in recent years. When a noise space has a certain volume and/or with complex channel, the method of active noise control (ANC) can be used to reduce or eliminate noise interference. The main channel delay in the active noise control system has an important impact on the performance of the ANC system, however, the traditional method, such as filtered-x least mean square algorithm (FxLMS), lacks the estimation of the main channel delay. This results that the system output cannot be accurately synchronized. Especially in the case of time-varying delay, the effect is less desirable. In this paper, the correlation time delay estimation is combined with FxLMS. A method to improve the performance of active noise control system (CTDE-FxLMS) is proposed based on time delay estimation. In CTDE-FxLMS method, the correlation time delay estimation is used to calculate the main channel delay, and the frequency response of the main channel is calculated by FxLMS. CTDE-FxLMS method improves the synchronization accuracy between the system output and the original noise in the time domain and the frequency domain. The computer simulation results show that the CTDE-FxLMS method has better noise reduction effect than the FxLMS method both the conditions of fixed delay and time-varying delay.
Highlights
With the development of economic level, people's requirements for environmental quality have gradually increased
The CTDE-filtered-x least mean square algorithm (FxLMS) algorithm enables the system to estimate the delay of the main channel and the ability to track the delay of the main channel, achieving higher synchronization accuracy of the original noise and cancellation waveform in the time domain, thereby improving the noise cancellation effect
In the representative application background, the rate and range of change of the main channel delay under environmental influence can be measured in advance
Summary
With the development of economic level, people's requirements for environmental quality have gradually increased. The above document guarantees the synchronization between the system and the main channel in the frequency domain through the improved FxLMS algorithm [11], but does not consider the influence of the delay difference between the main channel and the secondary channel on the system in the actual application scenario. The noise reduction target area or along a certain mechanical vibration, or by human impact during use, the relative position between the reference microphone and the secondary sound source may vary [15]. This causes the delay difference to not be treated as a constant or a priori acquisition. The simulation results show that CTDE-FxLMS method can effectively reduce the system error under the premise that the main channel delay is greater than the secondary channel delay
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