Patent ID: 11898453
Assignee: XI'AN JIAOTONG UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC F  G | IPC F  G

Claim 5:
6. The method according to claim 5, wherein in the fourth step (S4), since the sampling frequency is equal to rotational speed frequency, according to analysis on the aliasing situation of rotational frequency and multiplied frequency thereof, an under sampled spectrum is obtained by performing discrete Fourier transform on the original signal sequence, the frequency appears near the zero frequency in the under sampled spectrum, the frequency in the under sampled spectrum after blade vibration frequencies are aliased is extracted after a rotational speed frequency component is excluded, a frequency component with the maximum amplitude is extracted from the under sampled spectrum and is referred to as a frequency remainder fsub, the natural frequency difference Δf=f2sub−f1sub, and f2sub, f1sub respectively refer to the frequency remainders of a blade 2 and a blade 1.