Simulink Control Design™ - MathWorks

Effects of Time-Varying Source Blocks on Frequency

Response Estimation

Setting Time-Varying Sources to Constant for Estimation

Using Linear Analysis Tool

This example illustrates the effects of time-varying sources on estimation. The example

also shows how to set time-varying sources to be constant during estimation to improve

estimation results.

(^1) Open the Simulink model.
sys = 'scdspeed_ctrlloop';
open_system(sys)
(^2) Linearize the model.
a Set the Engine Model block to normal mode for accurate linearization.
set_param('scdspeed_ctrlloop/Engine Model','SimulationMode','Normal')
b Open the Linear Analysis Tool for the model.
In the Simulink Editor, select Analysis > Control Design > Linear Analysis.
c
Click Bode to linearize the model and generate a Bode plot of the
result.
The linearized model, linsys1, appears in the Linear Analysis Workspace.
(^3) Create an input sinestream signal for the estimation.
a Open the Create sinestream input dialog box.
In the Estimation tab, in the Input Signal drop-down list, select Sinestream.
b Open the Add frequencies dialog box.
Click.
c Specify the input sinestream frequency range and number of frequency points.
5 Frequency Response Estimation