초록 ▼

A method and apparatus of determining the transfer characteristic in an active-noise-control system, which involves generating white noise at an end of a one-dimensional sound field that is defined by a linear ventilating system in which sound travels essentially parallel to the extended direction o

A method and apparatus of determining the transfer characteristic in an active-noise-control system, which involves generating white noise at an end of a one-dimensional sound field that is defined by a linear ventilating system in which sound travels essentially parallel to the extended direction of the system; equalizing the transfer characteristic of the one-dimensional sound field and generating cancelling sound, according to an inverse of the transfer characteristic, to cancel the white noise and prevent noise being output from the other end of the one-dimensional sound field; continuously preventing the noise output and measuring the characteristic data of the one-dimensional sound field at, at least, one measuring point in the one-dimensional sound field; and calculating the transfer function of the one-dimensional sound field in the noise-output-prevented state, according to the characteristic data of the sound field.

대표청구항 ▼

A method of determining a transfer characteristic in an active-noise-control system, comprising the steps of: arranging an error-detection means for detecting a noise-cancelling effect, a speaker for generating noise-cancelling sound, the detection means and a speaker being inwardly spaced by a give

A method of determining a transfer characteristic in an active-noise-control system, comprising the steps of: arranging an error-detection means for detecting a noise-cancelling effect, a speaker for generating noise-cancelling sound, the detection means and a speaker being inwardly spaced by a given distance away from an end of a one-dimensional sound field that is defined by a linear ventilating system in which sound travels essentially parallel to the extended direction of the system, a noise detection means in the vicinity of a noise source in the one-dimensional sound field, and a transfer-characteristic-detection means between the noise-detection means and the error-detection means in the one-dimensional sound field; supplying an output of the noise-detection means to an adaptive filter that causes the speaker to generate noise cancelling sound, the adaptive filter involving a filter for preventing feedback sound according to an output of the error-detection means, a filter for modeling a transfer system between the speaker and the error-detection means, and a noise-cancelling filter whose parameters are continuously adjusted; and activating a transfer-characteristic determining means, through a sequencer when the noise detected by the error-detection means is minimized, to determine the transfer function of the one-dimensional sound field according to outputs of the noise-detection means and transfer-characteristic-detection means.