US 12,452,594 B2
Active noise control device, active noise control method, and active noise control program
Ryota Okawa, Yokohama (JP)
Assigned to TRANSTRON INC., Yokohama (JP)
Appl. No. 18/283,159
Filed by TRANSTRON INC., Yokohama (JP)
PCT Filed Feb. 18, 2022, PCT No. PCT/JP2022/006685
§ 371(c)(1), (2) Date Sep. 20, 2023,
PCT Pub. No. WO2022/202018, PCT Pub. Date Sep. 29, 2022.
Claims priority of application No. 2021-050005 (JP), filed on Mar. 24, 2021.
Prior Publication US 2024/0179463 A1, May 30, 2024
Int. Cl. G10K 11/178 (2006.01); H04R 3/04 (2006.01)
CPC H04R 3/04 (2013.01) [H04R 2400/01 (2013.01)] 6 Claims
OG exemplary drawing
 
1. An active noise control device comprising:
a microphone and a speaker;
an adaptive filter that generates a control signal by performing signal processing on a reference signal generated based on a vibration frequency generated by a vibration source, and sequentially updating the adaptive filter based on a signal input from the microphone when the control signal is output from the speaker;
a reference signal generation unit that generates the reference signal;
an amplitude characteristic calculation unit that acquires an acoustic characteristic including amplitude and phase information, the acoustic characteristic being an acoustic characteristic of a secondary path between the speaker and the microphone, and calculates an amplitude characteristic of the secondary path having a different value according to a first frequency based on the acquired acoustic characteristic;
a smoothed signal generation unit having a low-pass filter, that smooths the amplitude characteristic using the low-pass filter and generates a smoothed signal having a different value according to a second frequency;
a correction coefficient calculation unit that calculates a correction coefficient having a different value according to a third frequency based on a result of dividing the amplitude characteristic by the smoothed signal;
an adaptive filter update unit that updates the adaptive filter by subtracting an update term including the correction coefficient from a first adaptive filter coefficient that is an immediately preceding adaptive filter coefficient to obtain a second adaptive filter coefficient; and
a control signal generation unit that generates the control signal by multiplying the reference signal by the second adaptive filter coefficient.