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Zhang et al. / IJOCTA, Vol.15, No.4, pp.649-669 (2025)














































            Figure 2. A flowchart illustrating the golden sine subtraction-average-based optimizer (GSABO)–back-
            propagation (BP) neural network


            • Step 4: MFE is used to extract features from    bearing failures. The following are the parame-
              reconstructed signals and construct feature sets  ters: sampling frequency fs = 1200 Hz, number
              representing different states.                  of sample points N = 6000, fault impact dura-
            • Step 5: With the state feature set learned in   tion T = 0.01 s, fault characteristic frequency f
              Step 4, the GSABO–BP neural network classi-     = 1/T = 100 Hz, natural frequency f n = 3000
              fier can be guided during the classification pro-  Hz, displacement constant A 0 = 5, and damping
              cess. This structured approach enhances fault   coefficient g = 0.1.
              diagnosis accuracy by leveraging the strengths      Figure 4 illustrates the simulated signal’s
              of the GJO for parameter optimization, VMD      time-domain waveform. The noise obscures the
              for signal decomposition, MFE for feature ex-   rolling bearing’s periodic impact characteristics,
              traction, and GSABO–BP neural network for       inevitably diminishing the accuracy of the subse-
              feature classification.                         quent signal feature extraction process.
                                                                  The most popular and user-friendly technique
            4. Simulation analysis                            for diagnosing rolling bearing faults is the enve-
                                                              lope spectrum approach. Figure 5 presents the
            To validate the effectiveness of the VMD method,
                                                              envelope spectrum obtained from the simulated
            an early fault signal for rolling bearings was es-
                                                              signal.
            tablished, as shown in Equation (13):
                                                                  In order to diagnose the rolling bearing fault,
                                                              the simulated signal y(t) must be processed to re-
              y(t) = x(t) + n(t)
            
                                                             move interference components and enhance the
                     X                       p
                                                     2
              x(t) =    e −2πf ngt 0  · A 0 sin[2πf n  (1 − g ) · t 0 ]  accuracy of fault feature extraction.  As illus-
            
                      i                                       trated in Figure 5, background noise causes the
                                                       (13)   spectral line at the fault characteristic frequency
                where n(t) is Gaussian white noise, and x(t)  in the envelope spectrum to be less prominent.
            is the periodic impact signal produced by rolling  With significant interference present, identifying
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