sysid = ss(tfest(idfrd(sysfrd),2));
bode(sysid,sysfrd,'r*')
We used frequency response data with frequencies between 2,000 and 200,000 rad/s. The
identified model has a flat magnitude response for frequencies smaller than 2,000.
However, our estimation did not include those frequencies. To verify whether the
frequency response is flat for lower frequencies, estimate the response using a
sinestream input signal with frequencies of 20 and 200 rad/s.
lowfreq = [20 200];
inputlow = frest.createFixedTsSinestream(Ts,lowfreq)
The sinestream input signal:
Specifying Linearization for Model Components Using System Identification