Patent ID: 8098836
Filing Date: 2012-01-17
Classification: G10K

Abstract:
1. An active vibratory noise control apparatus comprising: reference wave signal generator for generating a reference wave signal having a frequency based on the frequency of vibratory noise generated by a vibratory noise source; an adaptive filter for outputting a control signal based on said reference wave signal in order to cancel said vibratory noise; vibratory noise canceller for outputting vibratory noise canceling sounds based on said control signal; error signal detector for outputting an error signal based on the difference between said vibratory noise and said vibratory noise canceling sounds; corrector for correcting said reference wave signal and outputting a corrected reference wave signal as a reference signal, based on a corrective value corresponding to signal transfer characteristics from said vibratory noise canceller to said error signal detector; and filter coefficient updater for sequentially updating a filter coefficient of said adaptive filter in order to minimize said error signal based on said error signal and said reference signal, wherein said vibratory noise canceller includes at least two first vibratory noise canceller disposed near a first space, and at least one second vibratory noise canceller disposed near a second space, and wherein said error signal detector includes either both at least one first error signal detector disposed near said first space, and at least one second error signal detector disposed near said second space, or only said first error signal detector; and switcher for changing the corrective value of said corrector from a first corrective value corresponding to signal transfer characteristics from said first vibratory noise canceller to said first error signal detector, or from a second corrective value corresponding to signal transfer characteristics from said second vibratory noise canceller to said second error signal detector, to a third corrective value corresponding to signal transfer characteristics from said second vibratory noise canceller to said first error signal detector, and changing the vibratory noise canceller for outputting said vibratory noise canceling sounds into said first space from said first vibratory noise canceller to said second vibratory noise canceller, when control characteristics of said vibratory noise have changed across a preset threshold value.