Specify Estimation Data

This topic shows how to specify estimation data for parameter estimation.

Create Experiment

Before you specify estimation data, create an experiment. At the MATLAB® prompt, open the nonlinear idle speed model of an automotive engine by typing

In the Simulink® model window, open the Parameter Estimation tool by selecting Analysis > Parameter Estimation.

In the Parameter Estimation tool, 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:

Edit Experiment Data

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.

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