I have a vibration signal sampled at 25.6 kHz, and I want to perform Envelope Analysis on it.
"Vibration-Based Condition Monitoring of Wind Turbines" by T. Barszcz has the following figure:
- I understand why the frequency is changing in the FFT plot during the HP and LP filters, but why is the frequency range changing from (b) -> (c) [0 -> 8 kHz] when performing the abs (rectifier) step? Cheers!
Edit: Here is an FFT for "Gearbox High Speed shaft" from my data.