% Assuming 'modelname' is your Simulink model name
model = 'modelname';
% Specify the input/output points for linearization
op = operpoint(model);
io = linearizeio(model);
% Specify sample time explicitly (adjust the sample time accordingly)
in = frest.Sinestream('Frequency',logspace(-2,2,100),'Amplitude',0.1);
% Perform frequency analysis
sys = frestimate(model, op, io, in, 'FrequencyVector', in.Frequency);
The error you are getting while trying to do frequency analysis (Bode plot) indicates that there may be a problem with the sample time of your Simulink signals. The error notice informs the user that the signal's sample time at the designated linearization input/output point is insufficient for frequency analysis.
You may want to take the following actions to deal with this issue:
Maintain Regular Sample Times:
Verify the consistency of the sample times for the input, output, and intermediate signals—the signals used in the linearization.
To comply with the specifications listed in the error message, you might need to modify the sample times in your Simulink model.
In Simulink, set the sample time:
Launch your Simulink model and examine the signal sample times.
throughout the linearization.
Adjust the signals' sample times consistently in accordance with the specifications listed in the error message.
Employ a Constant Sample Duration:
You might want to think about using continuous sample time for the linearization points if your model includes discrete sample times.
Give the sample time in fractions:
When using the frestimate function, you can define sample times manually. Make sure your Simulink signal's sample time corresponds to the one given in the frestimate function.
