Study On The Identification Of Vehicle Noise Source With Microphone Array Technology

Vehicles noise is one of the most important indexs in evaluation of the car comfort property. With people's growing concern about the noise of vehicles and the growing strict control of vehicle noise limits, controling of the vehicles noise has become an important and urgent task in the process of vehicle industrial development. However the identification of noise source is critical for noise control. Only by correctly identifying the sources of vibration and noise, we can analyze the mechanism of noise problems, and clearly definite the main problem of noise control, then solve it by twice the result with half the effort. This paper is based on the uniform circular microphone array technology, using MUSIC spatial spectrum estimation algorithm, identifying the noise source according to different speeds with set-state respectively, in order to find the main noise source and the distribution character of sound field, as well as provide the basis for future control of vehicle noise.This article firstly analyzes and summarizes the main noise source for vehicles, the noise transmission channels and forms, research situation of signal array processing, basic acoustic theory and wavelet theory, as well as sound localization methods.Then establish signal array model with uniform linear and circular arrays respectively based on microphone array statistical models. In this paper, it mainly discusses some important parameters which influence the array distinguish performance, such as the array function pattern, the minimum distance between array elements etc, and also it carries out a simulation analysis and comparison between the patterns of the uniform linear and circular arrays.Finally, through some comparison and analysis of spatial spectrum estimation, combing the characteristics of auto noise sources, this paper proceeds a simulation analysis of the single and dual sources through the MUSIC method. At the same time, it obtaines the three-dimensional spectrum and its projection, using microphone array technology for the car noise source identification test to find the main noise source.