Vehicular active noise control system

摘要

A frequency detecting circuit (150) estimates the frequency fp of a propeller shaft (76) based on the frequency fc of vehicle speed pulses, and calculates a control frequency fp' which is a harmonic of the frequency fp. A basic signal generator (316) generates a basic cosine wave signal xp1 and a basic sine wave signal xp2 of the control frequency fp'. Adaptive filters (156, 158) and an adder (160) generate a control signal Scp for canceling a driveline noise produced in a passenger compartment (14) by the propeller shaft (76). A speaker (30) outputs a canceling sound based on the control signal Scp into the passenger compartment (14).