Instantaneous Rotor Speed Estimation Based on Multisynchrosqueezing Transform Time-Frequency Analysis with Vibration Signals

Instantaneous speed (IS) measurement is critical in working condition monitoring of rotating machinery. In view of the fact that traditional methods cannot measure the IS with high accuracy and have failed under complex working conditions such as variable speed and strong variable speed. A novel method is proposed to estimate the IS of rotor of rotating machinery accurately. At first, the collected vibration signal is preprocessed. Secondly, Multisynchrosqueezing Transform (MSST), a high time-frequency (TF) energy aggregation TF analysis method, is carried out to obtain the TF distribution. Then Viterbi ridge extraction algorithm is used to extract the instantaneous frequency (IF) from the TF domain. Finally, IS is obtained through the linear relationship between IS and IF. Comparing with different TF analysis-based methods: Short-Time Fourier Transform (STFT), Chirplet Transform (CT), Fourth-order Synchrosqueezing Transform (4-SST), Reassignment Method (RM) and Synchroextracting Transform (SET), the proposed method can estimate the IF and IS more accurately in constant and variable speed simulation experiments as well as mechanical failure comprehensive simulation (MFS) bench experiments. Moreover, the proposed method can provide higher TF energy aggregation.