Thanks for this great tool!
I have one question.. I'm capable of fitting my frf data using the residual and poles output (it matches perfectly), but I also want to be able to create a tf using the natural frequency (wn), damping (b), magnitude modal constant (c) and phase modal constant (o).
Currently I create my tf as:
for i = 1:N %N=order of fit
H = H + tf(c(i),[1 2*b(i)*wn(i) wn(i)^2])
c(i) will have a minus sign if phase is 180/-180 deg.
Using this for loop I keep getting a mismatch between my manually created tf and the residuals and poles data.
Can anybody help me in trying to understand how to use those modal constants in the tf creation??
Thanks in advance!!
Careful: This function calculates the RMS for each point i by averaging from i to i+windowlength.
If you expect to see at point i the average of i +/- half the windowlength the result will be shifted to the left by windowlength/2.