Application of a Method of Identifiying Instantaneous Shaft Speed from Spectrum in Aeroengine Vibration Analysis

A novel and simple method to extract the instantaneous shaft velocity from the vibration signal. For a given vibration signal, the spectrum is first analyzed, and then the instantaneous shaft velocity is identified from the spectrum by the maximum tracking algorithm. Through the numerical integration of the instantaneous shaft velocity, the instantaneous phase is obtained and used for synchronous resampling in the digital domain, and then the subsequent synchronization analysis is carried out in the axial synchronous domain. A method of synchronous analysis of rotating machinery using only vibration signals is formed. An example of vibration response of aero-engine without rotational speed test is given, the practice shows that the instantaneous shaft velocity identified directly by the spectrogram can be used for synchronous sampling and subsequent periodic domain analysis and order domain analysis is feasible.