PURPOSE: To prevent the divergence of adaptive active noise elimination control for the engine booming noise in the car room by increasing the stability of a control system.
CONSTITUTION: Phase delay angles of vibration noises to engine exciting forces at respective rotational frequencies are found previously and stored in a ROM 3a. Then the phase of a reference signal to be filtered according to the engine rotational frequency has its delay corrected with the data in the ROM 3a to generate a secondary sound output signal 103, with which a secondary sound is generated by a speaker 6 and made to interfere with the filling noise, thereby performing noise elimination. Consequently, the engine rotational frequency does not decrease suddenly and the filling noise and secondary sound never become out of phase more speedily to prevent a noise increase, i.e., the divergence.
SAITO HIROYUKI
SATO KENJI
HASEGAWA SATOSHI
IGARASHI OSAMU
NISSAN MOTOR