| 摘要 |
PROBLEM TO BE SOLVED: To detect divergence inclination in an early stage when the divergence inclination is present on secondary noise or secondary vibration. SOLUTION: The phase difference of a first reference signal and a second reference signal can be changed to an angle other than 90°. Therefore, when the filter coefficient of first and second one-tap adaptation filter is diverted, two filter coefficients are successively renewed so as to draw a track of elliptical shape at a periphery of the optimum point on a two-dimensional plane making the two filter coefficients as respective axes. As a result, the divergence inclination of the filter coefficient is increased, a first control signal, a second control signal, a synthesized control signal and an error signal are increased. Accordingly, the divergence inclination present on the secondary noise or the secondary vibration can be detected in an early stage by performing determination based on those signals. COPYRIGHT: (C)2010,JPO&INPIT |
