航空发动机测试信号噪声特性分析

Noise Characteristics Analysis of Aero-Engine Testing Signals

在采集到的航空发动机测试信号中不可避免地混有噪声或干扰信号,讨论了利用频谱分析、滤波、小波分解、双谱估计、以及自相关分析等提取发动机信号噪声的方法,分析了发动机信号噪声的类型和特性。结果表明:发动机噪声主要是加性、低强度的连续频谱,在某几个频率成分上也分布着线状频谱。噪声中既有白噪声、又有非平稳的入侵色噪声。

The acquired data of aero-engine are somewhat contaminated with noise or disturbances. Different methods of noise separation such as the spectrum analysis, filtering,wavelet decomposition, hi-spectrum and auto-correlation analysis were discussed. Besides,the types and characteristics of noise radiated from the engine were analyzed. The results show that the engine noise is additive weak-intensity continuous spectrum or compound spectrum and for some frequencies it is both continuous and linear. The noise contains not only internal complex white noise but also non-stationary variance intrusion colored noise.