Simulink Control Design™ - MathWorks

identify. For example, to evaluate the tuning goal with an opening at a location named

'x', click Add signal to list and select 'x'.

TipTo highlight any selected signal in the Simulink model, click. To remove a signal

from the input or output list, click. When you have selected multiple signals, you can

reorder them using and. For more information on how to specify signal locations

for a tuning goal, see “Specify Goals for Interactive Tuning” on page 10-39.

Desired Response to Step Disturbance

Use this section of the dialog box to specify the shape of the desired response to the step

disturbance. Control System Tuner attempts to make the actual response at least as good

as the desired response.

• Response Characteristics

Specify the desired response in terms of time-domain characteristics. Enter the

maximum amplitude, maximum settling time, and minimum damping constant in the

text boxes.

• Reference Model

Specify the desired response in terms of a reference model.

Enter the name of the reference model in the MATLAB workspace in the Reference

Model text field. Alternatively, enter a command to create a suitable reference model,

such as tf([1 0],[1 1.414 1]).

The reference model must be stable and must have zero DC gain. The model can be

continuous or discrete. If the model is discrete, it can include time delays which are

treated as poles at z = 0.

For best results, the reference model and the open-loop response from the disturbance

to the output should have similar gains at the frequency where the reference model

gain peaks.

10 Control System Tuning