Feature Extraction and Selection Scheme for Intelligent Engine Fault Diagnosis Based on 2DNMF, Mutual Information, and NSGA-II

Figure 4

Vibration signals acquired from eight engine states: (a) normal state; (b) first cylinder misfire; (c) second cylinder misfire; (d) first and second cylinder misfire; (e) too large clearance of intake valve; (f) too large clearance of exhaust valve; (g) air leakage of the intake valve; (h) air leakage of the exhaust valve.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)