Instantaneous frequency extraction of full rub in touchdowns of AMBs based on polynomial chriplet transform

In this paper, polynomial chriplet transform (PCT) is introduced to extract the time-frequency characteristics of the rotor orbit during full rub in active magnetic bearings (AMB). In order to analyze the advantages and disadvantages of different time-frequency methods in the analysis of time-frequency characteristics of the signal, the short-time Fourier transform (STFT), Wigner-Ville distribution, general linear chirplet transform (GLCT) and PCT have been used to process the sample signal. Comparison between the four methods have been made and it is found that PCT has the highest accuracy in extracting the instantaneous frequency (IF) of the signal. Finally, PCT has been used to extract the IF during full rub in touchdowns of AMBs.