User`s guide

Identifying Hammerstein-Wiener Models
4 (Optional) If you want to try refining a previously estimated model, select
thenameofthismodelintheInitial model list.
Note The model structure and algorithm p roperties o f the initial model
populate the fields in the Nonlinear Models dialog box.
A model is available in the Initial model list unde r t he fo llowing
conditions:
• The model exists in the System Identification Tool GUI.
• The number of model inputs and o utputs matches the dimensions
of the Working Data (estimation data) you selected in the System
Identification Tool GUI.
5 Keep the d efault settings in the Nonlinear M odels dialog b ox that specify
the model structure and the algorithm, or modify the following settings:
• In the I/O N on linearity tab, specify whether to include or exclude the
input and output nonlinearities. For multiple-input and multiple-output
systems, you can choose to apply nonlinearities only to specific input
and output channels.
• In the I/O Nonlinearity tab, change the input and output nonlinearity
types and configure the nonlinearity settings.
Tip If you are not sure about which nonlinearity to try, start by using
the Piecewise Linear nonlinearity estimator.
• In the Linear Block tab, specify the model orders and delays. To gain
insight into possible d elays, click Infer Input Delay .
For more information about the available options, click Help in the
Nonlinear Models dialog box to open the GUI help.
6 Click Estim ate to add this model to the M odel Board in the System
Identification Tool GUI.
The Estimation tab displays the estimation progress and results.
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