Noise reduction method of multi-channel active noise reduction headrest

Abstract

The invention discloses a noise reduction method of a multi-channel active noise reduction headrest. Auricle space position information is obtained through an acquisition and calculation module; a point coordinate on the auricle is selected as a space coordinate of the virtual error microphone; time delay values from the secondary sound source and the physical microphone to the virtual error microphone are calculated through the physical microphone and the secondary sound source with known space coordinates, and a physical secondary path transfer function matrix Gpu from the secondary sound source to the physical microphone is obtained in an off-line modeling mode; a self-adaptive controller performs calculation to obtain a virtual error signal ev according to the reference signal, the physical error signal, the transfer function matrixes Gvu, M and Gpu and the intensity u(n) of the secondary sound source, performs calculation according to the reference signal and the virtual error signal to generate a noise elimination signal, and transmits the noise elimination signal to the secondary sound source; and the secondary sound source receives the noise elimination signal transmitted by the adaptive controller and makes a sound to counteract and reduce the original noise, so that the square of the sound pressure amplitude at the virtual error microphone is minimum.

Description

technical field [0001] The invention relates to the field of noise control, in particular to a noise reduction method for a multi-channel active noise reduction headrest. Background technique [0002] Noise pollution is a kind of environmental pollution that has a great impact on the human body. When people are in a high-noise environment for a long time, their work efficiency will decrease, and their hearing and physical and mental health will also be affected. Especially for transportation vehicles such as automobiles, high-speed rails, ships, and airplanes, the noise in the cabin area seriously affects the comfort of the passengers when riding, and the low-frequency noise components in the cabin noise are difficult to control. The volume has high requirements, which is difficult to meet in the cabin. Active noise control (ANC) technology has the characteristics of small size and good low-frequency noise control effect. Active noise control technology is based on the pri...

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Problems solved by technology

However, this patent only proposes a calculation method for the transmission path between the virtual microphone and the physical microphone when the head moves back and forth, left, and right, and uses the method of moving path estimation to calculate the maximum value of the residual noise of the system when the head is in different positions. Optimal virtual secondary path transfer function estimation value, the calculation amount increases sharply when complex motion

This method also models the human head as a rigid sphere, and the ears are on the surface of the rigid sphere, located on the diameter passing through the center of the rigid sphere, which does not match the actual situation and cannot achieve a good real control effect

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