Importing Models into CAGE

1. Start CAGE by typing cage at the MATLAB command line.

2. Select File > Import From Project. The CAGE Import Tool appears.

3. Click the Import From Project File button. Locate the example model file created in the Model Browser, Gasoline_project.mat, in the mbctraining directory, and click Open.

4. You can select from a list of models in the file. Select these models by Ctrl+clicking in the list:

   • BTQ

   • EXTEMP

   • knot (Type = Datum)

     In this case the knot model is duplicated because the datum model was used twice during modeling. The datum model tracked the maximum of the torque model, that is, MBT (the spark angle at maximum brake torque). This datum model was also used when modeling exhaust temperature and residual fraction, because it can be useful to see MBT on model plots for other factors. This is called a datum link model. You need only one copy of the knot model.

   • FX_0 (Check that the Location specifies RESIDFRAC, not EXTEMP)

     The response feature model FX_0 is RESIDFRAC at MBT. RESIDFRAC was constructed using a datum link (in this case knot, i.e., MBT) so FX_0 is residual fraction evaluated at the datum point (MBT).

   Check that your selection matches those shown.

   

5. Click the Import Selected Items button .

6. In the following Import dialog,

   • Double-click to edit the CAGE Model Name for the knot model to rename to MBT.

   • Double-click to edit the CAGE Model Name for the FX_0 model to rename to RESIDFRACatMBT.

   • Click OK to import the models.

7. Close the Import Tool and look at the Models view in CAGE. You should see the BTQ, EXTEMP, MBT, and RESIDFRACatMBT models in the list. The selected model is displayed in the other panes.

The objective is to produce optimized tables for spark and cam timings, subject to constraints on operating region, residual fraction, and the gradient of the cam phasers over the calibrated tables. You want the optimization to search for the timings that give the best torque and minimum fuel consumption, subject to the constraints.

You could fix the spark timing to be MBT spark (the spark angle that produces maximum brake torque) by using the MBT spark model as the spark input to the other models in the optimization. With spark fixed at MBT, you can set up an optimization that allows the two valve timings to vary, exploring the space via a gradient descent algorithm to locate the optimal timings. Remember, this is a simplified problem and running an engine at MBT is knock-limited and so is not possible at all operating points. For this example, you will not use the MBT model as you will use spark as a free variable in the optimization. You will return to the MBT model later.

Note you can also:

• Export models directly from the Model Browser to CAGE when both are open

• Use the CAGE Import Tool to import models directly from the Model Browser

• Use the CAGE Import Tool to import models and other calibration items (tables, optimizations, tradeoffs, data sets, features) from any project file created in CAGE or the Model Browser. This can help you use existing projects to speed up the setup of new sessions.

• Export models to a file which you can import to CAGE by selecting File > Import > Model

Optimized Calibration

Setting Up Calibration Tables to Fill

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