This example shows how to compare the performance of two different control system designs. Such comparison is useful, for example, to see the effects of different tuning methods or compensator structures.
In this example, the first design is the compensator tuned graphically in Bode Diagram Design (Control System Toolbox).
After tuning the compensator with this first tuning method, store the design in Control System Designer.
On the Control System tab, in the Designs section, click Store. The stored design appears in the Data Browser in the Designs area.
The stored design contains the tuned values of the controller and filter blocks. The app does not store the values of any fixed blocks.
To rename the stored design, in the Data Browser, double-click the design, and specify a new name.
On the Control System tab, tune the compensator using a different tuning method.
Under Tuning Methods, select
To design a controller with the default
time specifications, in the PID Tuning dialog box, click
Update all plots to reflect both the new design and the stored design.
On the Control System tab, click Compare.
In the Compare Designs dialog box, the current design is checked by default. To compare a design with the current design, check the corresponding box. All analysis plots update to reflect the checked designs. The blue trace corresponds to the current design. Refer to the plot legend to identify the responses for other designs.
To compare a stored design with the current design, the sample times of the current design and stored design must be the same. To modify the sample time of the current design to match that of a stored design, on the Control System tab, click Edit Architecture. Then, in the Edit Architecture dialog box, on the Linearization Options tab, specify the working domain and rate conversion method.
Under some conditions, it is useful to restore a previously stored design. For example, when designing a compensator for a Simulink® model, you can write the current compensator values to the model (see Update Simulink Model and Validate Design). To test a stored compensator in your model, first restore the stored design as the current design.
To do so, in Control System Designer, click Retrieve. Select the stored design that you want to make current.
As with design comparison, to retrieve a stored design, the sample times of the current design and stored design must be the same.
The retrieved design overwrites the current design. If necessary, store the current design before retrieving a previously stored design.