PURPOSE: To decrease the calculation volume of convolutional operation executed in an active noise controller for vehicle and to prevent the degradation of noise decrease control.
CONSTITUTION: A reference signal (x) consisting of an impulse train which has the same period as indistinct sound generated by an engine is generated and outputted by a reference signal generating part 11 based on a crank angle signal X synchronized with the crank angle of this engine. Driving signals y1 to y4 are generated in a driving signal generating part 13 by convolution of an adaptive digital filter Wm and the reference signal (x), and a reference processing signal r1m is generated in a reference processing signal generating part 14 by convolution of a transfer function filter C1m and the reference signal (x). It is discriminated whether the period of the reference signal (x) is periodically changed or not by a periodicity discriminating part 18; and if it is periodically changed, processing contents of an adaptive processing part 17 are properly changed by a divergence suppressing part 19.
DOI MITSUHIRO
HIRANO IZUHO
NAKAJI YOSHIHARU
MURAOKA KENICHIRO
