This model has the same plant and controller. However, the Frequency Response
Estimator block in this model is configured to use the Superposition experiment mode.
In this mode, all the sine waves are added together and injected to the plant at the same
time. Compared with the sinestream experiment, the superposition experiment is must
faster (especially when you are targeting low frequencies).Find a steady-state operating point with plant output of -0.5. Linearize the plant to find a
baseline response at this operating point, G2. The Frequency Response Estimator block is
configured to use this baseline to generate a Bode plot.op.Outputs.y = -0.5;
op_point = findop(plantMDL,op,options);
G2 = c2d(linearize(plantMDL,op_point),Ts);The experiment starts at 10 sec after the PID controller moves the plant to the new
operating point (y = -0.5). Note that the recommended experiment length is 377 seconds,
much shorter than 1738 seconds used in the sinestream experiment. Simulate the model
and again observe the progress of the estimation on the Bode plot.6 Online Frequency Response Estimation