Getting model from frequency response
Getting model from frequency response
(OP)
Hi All,
I need to know how can we get a mathematical model(state space or transfer function) from frequency response?
The frequency response is resulted from FFT analysis (Force vs. Acceleration.
Thank you in advance for any reply.
sweetday
I need to know how can we get a mathematical model(state space or transfer function) from frequency response?
The frequency response is resulted from FFT analysis (Force vs. Acceleration.
Thank you in advance for any reply.
sweetday





RE: Getting model from frequency response
TTFN
RE: Getting model from frequency response
Regards
Dave
RE: Getting model from frequency response
It is obtained from the complex spectra of the two signals in a variety of ways, known as H1 H2 H3 and HV (the latter being an engineer's joke by a Mr Harvard Vold).
H1 = (BxA*)/(AxA*)
where B and A are the original complex spectra of each channel, and * means conjugate.
Each of these H formulations has its uses, as they are snsitive in different ways to the noise in each of the data channels. Obviously H1 is more sensitive to errors in A than B for example.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Getting model from frequency response
There are many ways, get Ewins book.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.