method and device for predicting noise in motor vehicles

摘要

A jig (14A) is successively mounted on each of the four wheels (10) of a vehicle. The jig (14A) is struck in three orthogonal directions independently by an impulse hammer (14B), and at the same time, a microphone (16) inside the vehicle measures the sound pressure of the noise generated due to the exciting force of the impact. An FFT analyzer (18A) operates a frequency response function from the exciting force to the sound pressure of the noise. In a drum testing machine (2A), a tire (26) which is to be subject to noise prediction is mounted on a shaft, the subject tire (26) is rotated, and the axial force in the three orthogonal directions is measured. The axial force signal is input to the FFT analyzer (18B) and the auto power spectrum of the axial force in the three orthogonal directions and the cross power spectrum between two different axial directions are operated. The frequency response functions of all of the four standard tires are synthesized with four of the auto power spectrums and the cross power spectrums of the subject tire and the power spectrum of the road noise is operated. IMAGE