US 12,243,509 B2
Active noise reduction system
Xun Wang, Saitama (JP); and Toshio Inoue, Saitama (JP)
Assigned to HONDA MOTOR CO., LTD., Tokyo (JP)
Filed by HONDA MOTOR CO., LTD., Tokyo (JP)
Filed on Mar. 1, 2023, as Appl. No. 18/176,771.
Claims priority of application No. 2022-055879 (JP), filed on Mar. 30, 2022.
Prior Publication US 2023/0317050 A1, Oct. 5, 2023
Int. Cl. G10K 11/178 (2006.01)
CPC G10K 11/17883 (2018.01) [G10K 11/17817 (2018.01); G10K 11/17854 (2018.01); G10K 2210/1282 (2013.01); G10K 2210/3055 (2013.01); G10K 2210/3221 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An active noise reduction system for reducing a noise in an internal space of a mobile body, the active noise reduction system comprising:
a reference signal generator configured to generate a reference signal corresponding to the noise;
a canceling sound output device configured to output a canceling sound for canceling the noise;
an error detector configured to detect an error between the noise and the canceling sound and generate an error signal corresponding to the error;
a reference distance detector configured to detect a reference distance that is a distance from the canceling sound output device to a head position of an occupant; and
a controller configured to control the canceling sound output device based on the reference signal, the error signal, and the reference distance,
wherein the controller is configured to:
generate a first canceling estimation signal based on the reference signal, the first canceling estimation signal being an estimation signal of the canceling sound at a position of the error detector;
generate a second canceling estimation signal by adjusting a time delay and an amplitude of the first canceling estimation signal based on the reference distance, the second canceling estimation signal being an estimation signal of the canceling sound at the head position of the occupant; and
update a control filter based on the second canceling estimation signal, the control filter being a filter for controlling the canceling sound output device.