logdata = logsout{1}.Values
logdata =
struct with fields:
Ready: [1×1 timeseries]
Perturbation: [1×1 timeseries]
PlantInput: [1×1 timeseries]
PlantOutput: [1×1 timeseries]
The Ready field is a timeseries containing a logical signal that indicates which time steps
contain the data to used for the estimation. For a sinestream signal, this field indicates
which perturbation periods for the estimation to discard (settling periods).
Perturbation contains the sinestream perturbation applied to the plant. The
PlantInput and PlantOutput timeseries contain the signals at the block inputs u and
y, respectively.
Estimate Frequency Response
If you collect this data in a deployed environment with limited computational resources,
you can use the data to perform frequency response estimation offline, using the
frestimate command. Give frestimate the logdata structure and the same
frequencies you used for the Frequencies parameter in the block. frestimate
processes logdata to obtain a frequency response data (frd) model containing the
estimated responses at those frequencies.
sys_estim = frestimate(logdata,w,'rad/s');
size(sys_estim)
FRD model with 1 outputs, 1 inputs, and 20 frequency points.
Examine the estimated frequency response.
figure
bode(sys_estim,'b*')
Collect Frequency Response Experiment Data for Offline Estimation