User`s guide

3 Linear Model Identification
Note For etfe,onlytheLinear option is available.
– In the Frequencies field, enter the number of frequency points.
For time-domain data, the frequency ranges from 0 to the Nyquist
frequency. For frequency-domain data, the frequency ranges from the
smallest to the largest frequency in the data set.
4 In the Frequency Resolution field, enter the frequency resolution, as
described in “Options for Frequency Resolution” on page 3-6. To use the
default value, enter
default or, equivalently, the empty matrix [].
5 In the Model Name field, enter the name of the correlation analysis mode l.
The model name should be unique in the Model Board.
6 Click Estim ate to add this model to the M odel Board in the System
Identification Tool GUI.
7 In the Spectral M odel dialog box, click Close .
8 To view the frequency-response plot, select the Frequenc y res p check
box in the System Identification Tool GUI. Fo r more information about
working with this plot, see “Using Frequency-Respons e Plots to Validate
Models” on p ag e 8-32.
9 To view the estimated disturbance spectrum, s elect the Noise spectrum
check box in the System Identification Tool GUI. For more information
about working with this plot, see “Creating Noise-Spectrum Plots” on page
8-40.
10 After estim a t in g the m o del, see Chapter 8 , “Model Analysis”, to valid a te
the model.
To export the model to the M ATLAB wo r kspace, drag it to the To Workspace
rectangle in the System Identification Tool GUI. Y ou can retrieve the
responses from the resulting
idfrd model object using the bode or n yquist
command.
3-4