微速差双转子信号分离方法精度研究OA北大核心CSTPCD

The separation of micro-speed difference signals within differential frequency 1 Hz is a challenge in the field of dual-rotor vibration feature extraction.Zoom-FFT(ZFFT)is a classical algorithm for extracting the features of signals with similar frequencies.However,it needs sufficient data length to achieve a good signal separation effect.In order to improve the signal frequency resolution without increasing the data length,the ZFFT+FT algorithm is generated on the basis of ZFFT algorithm.The extraction accuracy of the algorithm for micro-speed difference signals with frequency difference of 1 Hz and 0.5 Hz was studied through LabVIEW software simulation experiments,and compared with that of chirp Z transform(CZT),ZFFT and FFT algorithms.The extraction accuracy was measured by the relative error and variance of the extraction results.Field experiments were carried out in the coaxial micro-speed difference dual-rotor test stand,and the extraction results of 28s dataset of micro-speed difference signal by FFT were compared with those of 4s dataset extracted by CZT,ZFFT and ZFFT+FT algorithms.The maximum error between ZFFT+FT algorithm and FFT algorithm is 0.56 μm,which verifies the real-time performance and accuracy of ZFFT+FT.The results indicate that the ZFFT+FT algorithm can accurately extract the micro-speed difference signals within frequency difference of 1 Hz in real time.The research results can provide reference for the extraction of micro-speed difference signals in rotating machinery.