Vibration Analysis for Machine Monitoring and Diagnosis: A Systematic Review

Table 8

The advantages and disadvantages of time-frequency domain methods.

Time-frequency domain methods	Advantages	Disadvantages
WT	Provide a superior time localization at high frequencies compared to STFT, more flexible compared to STFT, availability of various wavelet functions	Suffers from the convolution of a priori basis functions with the original signal, difficult to choose the mother wavelet type
WVD	Has a good time and frequency resolution, does not require window function for its implementation	Vulnerable to interference, slower than STFT
HHT	Has a good time and frequency resolution, does not require priori basis functions	Result misinterpretation due to IMFs generated at the low-frequency region
STFT	Straightforward method and recommended for beginners in the time-frequency analysis, low computational complexity	Constant frequency resolution for the whole signal, difficult to find a fast and effective algorithm to calculate STFT
PSD	Can be directly computed by FFT, requires very little processing power	Frequency resolution is affected by the window size