Rotating blade vibration measurement and condition monitoring are of great significance for improving the operational safety of Aero-engines. In this paper, we analyze the feasibility of measuring rotating blade vibration using a micro-Doppler sensing technique which free from undersampling and high-intervention issues. This paper preliminarily establishes a rotating blade microwave scattering model and indicates that the blade's vibration is contained in the phase of the measured microwave signals. Thus, the key to measuring the vibration of a rotating blade lies in extracting its phase or its derivative, thereby implying two potential approaches for vibration parameter extraction: instantaneous phase-based approach and instantaneous frequency-based approach. The proposed models and methods are validated by simulations.

Rotating blade,microwave sensor,blade scattering model,vibration measurement,parameter identification