To accurately detect a frequency of a dip and stably control noise when a frequency of the noise matches the frequency of the dip.SOLUTION: An active noise control system 1 has an adaptive filter that generates a control signal by performing signal processing of a reference signal generated based on a vibration frequency generated by a vibration source, and successively updates the adaptive filter based on a signal input from a microphone when the control signal is output from a speaker. Acoustic characteristics of a secondary path between the speaker and the microphone, including amplitude and phase information, are obtained, amplitude characteristics of the secondary path with different values depending on the frequency are calculated, the amplitude characteristics are smoothed to generate smoothed signals with different values depending on the frequency, and the amplitude characteristics are divided by the smoothed signals to calculate correction coefficients with different values depending on the frequency. The adaptive filter is updated by subtracting an update term including the correction coefficients from a first adaptive filter coefficient that is a previous adaptive filter coefficient, to obtain a second adaptive filter coefficient.SELECTED DRAWING: Figure 2
【課題】ディップの周波数を正確に検出し、騒音の周波数がディップの周波数と一致する場合にも安定して騒音を制御する。【解決手段】アクティブノイズ制御装置1は、振動源で発生した振動周波数に基づいて生成された参照信号を信号処理して制御信号を生成する適応フィルタを有し、スピーカから制御信号を出力したときにマイクロホンから入力された信号に基づいて適応フィルタを逐次的に更新する。振幅と位相の情報を含む、スピーカとマイクロホンとの間の二次経路の音響特性を取得し、周波数に応じて値が異なる二次経路の振幅特性を算出し、振幅特性を平滑化して周波数に応じて値が異なる平滑化信号を生成し、振幅特性を平滑化信号で除算して、周波数に応じて値が異なる補正係数を算出する。補正係数を含む更新項を直前の適応フィルタ係数である第1適応フィルタ係数から減算することで適応フィルタを更新して第2適応フィルタ係数を求める。【選択図】図2
ACTIVE NOISE CONTROL DEVICE, ACTIVE NOISE CONTROL METHOD AND ACTIVE NOISE CONTROL PROGRAM
アクティブノイズ制御装置、アクティブノイズ制御方法及びアクティブノイズ制御プログラム
2022-10-06
Patent
Electronic Resource
Japanese
ACTIVE NOISE CONTROL DEVICE, ACTIVE NOISE CONTROL METHOD, AND ACTIVE NOISE CONTROL PROGRAM
European Patent Office | 2022
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