This topic shows how to specify estimation data for parameter estimation.
Before you specify estimation data, create an experiment. At the MATLAB® prompt, open the nonlinear idle speed model of an automotive engine by typing
engine_idle_speed
In the Parameter Estimator, on the Parameter Estimation tab, click New Experiment.
This action creates an experiment called Exp
in the
Experiments list in the Data Browser
panel and opens the experiment editor. To change the name of the experiment,
right-click Exp
and select Rename. If
you rename it NewData
, the Experiments list
now looks like this:
After creating an experiment, launch the experiment editor by right-clicking on the experiment name and selecting Edit... from the list. The experiment editor resembles the following figure.
The experiment editor has four panels. You select output signals and import output data in the Outputs panel. You select input signals and import input data in the Inputs panel. You can specify model initial states in the Initial States panel. You can specify parameters to estimate in the Parameters panel.
The rows in the Inputs panel of the editor correspond to
Inport block BPAV
in the engine_idle_speed
model. See Import Data for Parameter Estimation.
The rows in the Outputs panel correspond to Outport block
Engine Speed
. You can import signal data from files or
MATLAB workspace.
The idle-speed model of an automotive engine contains the measured data stored in
the iodata
array in the workspace. The array contains two
columns: the first for input data, and the second for output data. The time data is
in the time
array in the workspace. Import the input data by
typing [time,iodata(:,1)]
in the dialog box in the
Inputs panel.
Import the output data by typing
[time,iodata(:,2)]
in the dialog box in the
Outputs panel.
Note
You can have more than one input or output signal, but you can have only one data set for a signal. If you have multiple data sets, create multiple experiments.