Research on signal separation method of micro-speed difference dual-rotor based on ZFFT and FT algorithm

Abstract

Aiming at the problem that the traditional analysis methods such as Zoom-FFT (ZFFT) heavily depend on the data length in the frequency separation accuracy when separating the unbalanced signals of the inner and outer rotors of the dual-rotor system with micro-speed difference, an improved method based on ZFFT + FT was proposed to refine the signal spectrum and accurately identify the unbalanced response of the inner and outer rotors. On the basis of sampling and filtering the micro-speed difference signal by ZFFT, DFT was used to refine the frequency segment, so as to extract the corresponding amplitude of the operating frequency components of the inner and outer rotors. The basic principles of Chirp-Z transform (CZT), ZFFT, and ZFFT + FT algorithms were introduced, and the corresponding programs of each algorithm were written based on LabVIEW software for simulation, then the signal generator was used to carry out the micro-speed difference signal extraction test and finally the dynamic balance test was carried out on the dual-rotor test bench. Data simulation and field test show that compared with the CZT and ZFFT methods, the method has better frequency resolution ability and can separate the micro-speed difference signal with higher accuracy, and has high feasibility and practicability in the dynamic balance of the micro-speed difference dual-rotor system.