ACTIVE CONTROL METHOD AND SYSTEM OF EXHAUST NOISE OF AN INTERNAL COMBUSTION ENGINE USING INTERFERENCE CAUSED BY NONLINEARITY OF ULTRASONIC WAVES

摘要

The present invention relates to a noise reduction technology for actively controlling exhaust noise of an internal combustion engine such as an engine of an automobile. In particular, the present invention relates to an ultrasonic wave instead of a speaker normally used in the existing active noise control technology to generate an offset sound that cancels exhaust noise. The generator generates at least one pair of ultrasonic waves having a frequency difference corresponding to a predetermined frequency of the exhaust noise to be removed, and produces an offset sound by the interference effect of two ultrasonic waves by acoustic nonlinearity. A system and method for actively removing is provided.