Internal Combustion Engine Fault Identification Based on FBG Vibration Sensor and Support Vector Machines Algorithm

Figure 7

Comparison of time domain and frequency domain characteristics. (a) Time domain diagram of normal state signal, (b) frequency diagram of normal state signal, (c) time domain diagram of abnormal state signal, and (d) frequency diagram of abnormal state signal.

(a)

(b)

(c)

(d)