混响系统源波形间接恢复的研究

On Indirect Recovery of Source Waveform in Reverberating System

多源非平稳冲击激励、时变的传递路径、宽频非平稳振声响应以及混响、消散、模态密集等现象 ,是发动机、柴油机等混响系统的重要特性 ,制约着激励源波形和故障信息的直接测取 ,使利用包容着激励源特征和路径因素的振动响应间接恢复源波形的研究思路成为当前的研究热点。本文对制约混响系统源波形间接恢复的主要动力学特性——混响与消散进行了深入的理论分析和探讨 ,提出了基于非精确传递函数以最佳傅里叶滤波与复倒谱相结合的激励源波形间接恢复方法。

Reverberating system such as diesel engine is characteristic of mutli source non stationary impulsive excitations, time varying transfer behavior, unstable vibroacoustic responses as well as reverberation, dispersion, concentrated mode, which limit direct determination of transient excitation and fault information. We focus our research on the vibration responses that include the source′s features and path information. Based on the theoretical analysis of the properties of reverberation and dispersion, an indirect recovery method which combines Fourier filter with complex cepstrum on the basis of inaccurate transfer function is proposed. Experiments of cylinder verify its validity.