Getting Started

Example: Time and Frequency Responses
of the DC Motor

The section entitled SISO Example: the DC Motor presented a DC motor example. If you have not yet built that example, type

load ltiexamples

at the MATLAB prompt. This loads several LTI models, including a state-space representation of the DC motor called sys_dc.

Opening the LTI Viewer

To open the LTI Viewer, type

ltiview

This opens an LTI Viewer with an empty step response plot window by default.

Importing Models into the LTI Viewer

To import the DC motor model, select Import under the File menu. This opens the LTI Browser dialog box, which lists all the models available in your MATLAB workspace.

Figure 3-2: The LTI Browser with the DC Motor Model Selected

Select sys_dc from the list of available models and click OK to close the browser. This imports the DC motor model into the LTI Viewer.

To select more than one model at a time, do the following:

• To select individual (noncontiguous) models, select one model and hold down the Ctrl key while selecting additional models. To deselect any models, hold down the Ctrl key while you click on the highlighted model names.
• To select a list of contiguous models, select the first model and hold down the Shift key while selecting the last model you want in the list.

The picture below shows the LTI Viewer with a step response for the DC motor example.

Figure 3-3: Step Response for the DC Motor Example in the LTI Viewer

Alternatively, you can open the LTI Viewer and import the DC motor example directly from the MATLAB prompt.

ltiview('step', sys_dc)

See the ltiview reference page for a complete list of options.

LTI Viewer

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