Bode Plot
  • Alex thank you for sharing experience. I want to ask something that I am stuck. I am working on frequency domain analysis on my thesis. I read your simplebgc documentation. I have physical system but I dont know how can I construct a stimulus signal that cover wide range frequency, you suggest white noise or sine sweep signal. How can I construct these signals. Can you suggest any documentation to do that ? Thank you.
  • Hello,
    Sine sweep is simple - just change frequency as a function of time, out = a*sin(w*t), w = func(time), linear curve which covers the desired range from w1..w2 for the given time T:
    w = w1 + (w2-w1)*t/T
    amplitude A may be function of frequency, to increase stimulus where system response falls (like for gimbals, it falls at high frequencies)

    For white noise, I use random number generator, passed through band-pass filter or other digital filter depending on the desired shape.

    I found that white noise as a stimulus works much better than sine sweep, so I prefer using it.