Research Article
Applications of Fractional Lower Order Frequency Spectrum Technologies to Bearing Fault Analysis
Figure 15
Frequency spectrum estimations of the signal with closely spaced frequencies employing fractional lower order frequency spectrum methods ((a) fractional lower order Blackman-Tukey method; (b) fractional lower order Periodogram method; (c) fractional lower order Welch covariation method; (d) fractional lower order AR model method; (e) fractional lower order ARMA model method).