PURPOSE: To reduce the vibration having the variable level, economizing energy, by installing a means for carrying out the adjustment so that the control state in a frequency region where the frequency of the control object vibration and the resonance frequency of a vehicle accord is different from the control state in the frequency region where both the frequencies do not accord.
CONSTITUTION: The number of revolution of an engine in the case when the secondary noise frequency and the primary cavity resonance frequency in the longitudinal direction of a car interior accord each other is obtained, and an according frequency region is formed. An adjusting means 40 calculates the revolution cycle of an engine E on the basis of the pulse signals (w) supplied from an ignition coil 24, and the number of revolution is obtained. When the number of revolution of the engine is within the above-described region, the adjusting means 40 sets the factor of an amplitude adjustor 42 to 1, and inputs the output signal (x) of a reference signal generating means 8 into a driving signal generating means 6, keeping the amplitude as it is, and the oridnary vibration reducing control is carried out. When the number of revolution of the engine is outside the above-described region, the factor is set to 0, and the driving signal (y) is not generated, and the vibration reducing control is not carried out. Since the control taking account of the balance between the electric power consumption and the reducing effect, the effective utilization of the electric power can be achieved.
IKEDA NAOKI
SOMAI HIROSHI
NAKAO NORIHIKO
MITSUFUJI CHIAKI
TSUKAHARA YUTAKA
HARADA SHINGO
