Before you begin data import, create an experiment. Simulink® Design Optimization™ software provides a tool for setting up the estimation session.
To create an estimation session:
At the MATLAB® prompt, open the nonlinear idle speed model of an automotive engine by typing :
The model contains the Inport block
Engine Speed for importing input
and output data, respectively. To learn more, see Model Requirements for Importing Data.
In the Simulink model window, open the Parameter Estimation tool by selecting Analysis > Parameter Estimation.
Parameter Estimation Tool
You can organize the estimation and validation tasks inside Experiments under Data Browser panel on the left. You can assign each experiment to an estimation task or validation task.
To create an experiment, click the New Experiment button.
This creates an experiment
Exp under Experiments.
To change the name of the experiment, right-click and select Rename.
Note: The Simulink model must remain open to perform parameter estimation tasks.
Experiments are collections of signal data, specifically input and output signal data. After you create an experiment, as described in Create Experiment, you can import data into your experiment from various sources including MATLAB® variables, MAT-files, Excel® files, or comma-separated-value files.
To import data into your experiment right-click and select Edit.... This will launch the experiment editor. In the experiment editor, you can define the signals contained in the experiment.
For example, the rows in the Inputs panel
of the editor correspond to Inport block
The rows in the Outputs panel correspond
to Outport block
Engine Speed. You can import signal
data from files or MATLAB workspace.
Note: The Simulink model must contain an Inport or Outport block or logged signals to enable importing data. For more information, see Model Requirements for Importing Data. To select more output signals to specify data for, click Select Measured Output Signals in the Outputs panel.
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
in the workspace. You can import the input data by typing
the Inputs panel.
You can import the output data by typing
the Outputs panel. You can view the data by clicking
. The input data should
look like this:
Output data should look like this:
After importing the data for
the experiment editor looks like this:
To import data from a file, click the button.
To learn more about the Edit Experiment: dialog box, see Experiment Editor.
Time-series data is stored in time-series objects. For more information, see Time Series Objects in the MATLAB documentation.
When you import input data from a time-series object,
for parameter estimation, you must specify the time vector and data
[t.time,t.inputdata] in the Inport signal dialog
box. Similarly, to import output data, you must specify the time vector
and data as
[t.time,t.outputdata] in the Outport
signal dialog box. For more information on how to import data into
the experiment, see Time-Domain Data.
Complex-valued data is data whose value
is a complex number. For example, a signal with the value
complex. You can use complex data to estimate parameters of electrical
systems, such as the magnitude and phase.
Note: You must sample the real and imaginary parts of the data as a function of the same time vector.
To use complex data for parameter estimation:
Create two signals, one for the real part and one for the imaginary part for the Inport or Outport block.
Select both signals in the experiment editor.
Import the data to the corresponding signal as described in Time-Domain Data.