Microphone calibration for active noise control system
AssigneeSiemens VDO Automotive Corporation
InventorPhilip Edward Arthur Stuart
Life of this patent
Estimating the term…
Abstract
An active noise control system (100) and method compensates for changes in a microphone output to maintain accurate noise control. A calibration signal reflecting a desired microphone output is generated and stored in an active noise control module (106). During operation, the active noise control module (106) compares an actual microphone output signal with the calibration signal and compensates for any changes in the actual output signal before any noise compensation or cancellation function occurs.
Claims16
An active noise control method, comprising:
- generating a saved calibration signal corresponding to a first microphone output during a known engine noise condition;
- storing the calibration signal in an active noise control module, wherein the active noise control module generates an anti-noise;
- comparing the calibration signal with an actual microphone output corresponding to the known engine noise condition;
- adjusting the microphone output based on the comparing step;
- and
- generating the anti-noise corresponding to the adjusted microphone output to control a detected noise.
An active noise control method, comprising:
- generating a saved calibration signal corresponding to a first microphone output during a known engine noise condition;
- storing the calibration signal in an active noise control module, wherein the active noise control module generates an anti-noise;
- comparing the calibration signal with an actual microphone output corresponding to the known engine noise condition;
- adjusting the microphone output based on the comparing step, including determining a difference between the actual microphone output and the calibration signal, calculating a compensation factor based on the determined difference, and adding the compensation factor to the actual microphone output;
- and
- generating the anti-noise corresponding to the adjusted microphone output to control a detected noise.
An active noise control method for a vehicle engine, comprising:
- generating a calibration signal corresponding to a first microphone output corresponding to an absolute noise characteristic generated by the vehicle engine, where the absolute noise characteristic comprises a known engine noise condition without noise attenuation;
- storing the calibration signal in an active noise control module, wherein the active noise control module generates an anti-noise signal;
- comparing the calibration signal with an actual microphone output corresponding to a detected engine noise;
- determining a difference between the actual microphone output and the calibration signal;
- calculating a compensation factor based on the determined difference;
- adding the compensation factor to the actual microphone output to adjust the anti-noise signal;
- and
- generating an anti-noise corresponding to the anti-noise signal, wherein the anti-noise mixes with the detected engine noise to generate a new detected engine noise.
An active noise control system for controlling noise from a vehicle engine, comprising:
- a microphone that detects a detected engine noise from a vehicle engine and generates a microphone output based on the detected engine noise;
- an active noise control module that generates an anti-noise signal, the active noise control module having a memory that stores a calibration signal corresponding to a first microphone output during a known noise condition representing an absolute noise characteristic generated by the vehicle engine, and a processor that compares the calibration signal with an actual microphone output corresponding to a detected engine noise and adjusts the anti-noise signal based on the comparison;
- and
- a noise cancellation module that receives the anti-noise signal from the active noise control module and outputs an anti-noise corresponding to the anti-noise signal, wherein the anti-noise mixes with the detected engine noise to generate a new detected engine noise.
Dependencies are inferred from the claim text.