Fault Diagnosis of Electric Impact Drills Based on Time-Varying Loudness and Logistic Regression

Figure 9

Acoustic signal analysis of Case 3: (a) acoustic signal of healthy EID-c, (b) acoustic signal of faulty EID-c, (c) time-varying specific loudness of healthy EID-c, (d) time-varying specific loudness of faulty EID-c, (e) time-varying loudness of healthy EID-c and faulty EID-c, and (f) time-varying loudness spectrum of healthy EID-c and faulty EID-c.

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