Set Up Modal Optimizations

You can use the modal optimization algorithm to produce optimal calibrations for engines with multiple operating modes. This algorithm helps you choose the best operating mode for each operating point. The algorithm can optimize an objective for each operating mode and select the best solution automatically. You must use a composite model for these optimizations. See What Are Composite Models?

The optimization output views help you view and select the best solution for each operating point.

Workflow for Modal Optimization

To find the best mode at each operating point:

  1. Create a composite model representing the multiple operating modes. See Create Composite Models.

  2. Using the Optimization Quick Start Tool, select the Modal optimization type. The tool then selects the mode input as an optimization variable.

    Your optimization is ready to run, unless you want to change the optimization points or add additional constraints or extra objectives. See Adding Extra Objectives to Modal Optimizations and Analyze Modal Optimization Results.

  3. After running the optimization, use the optimization output graphical tools to view the solutions and decide which mode you want to use for each operating point.

    The modal optimization algorithm tries to automatically select the best mode for each operating point. Use the optimization output node tools to view all solutions and see which solution is selected. You can change the selections manually if you want. These tools are also useful for selecting solutions for multiple objective optimizations, such as NBI.

For CAGE options, see Modal optimization Parameters.

You can only use modal optimization for point optimization problems. When you have selected the best mode for each operating point, you can create a sum optimization from your modal optimization results. The toolbox automatically creates a sum optimization for you with your selected best mode for each operating point.

To analyze your results, see Analyze Modal Optimization Results.

Adding Extra Objectives to Modal Optimizations

You can optionally add additional objectives in the Optimization view. You can optimize with one objective and use the other objectives to explore the results with graphical comparisons. You can manually change the selected best mode based on the values of these additional “helper” objectives. You can optionally choose to automatically select the best mode with a different objective.

To add extra objectives:

  1. In the Optimization view, right-click the Objectives pane and select Add Objective. Set up the extra objective as described in Edit Objective. The extra objective should be a point objective. A sum objective will work but will be the sum of a single number.

  2. Optionally, you can change which objective to use to select the best mode. By default, CAGE uses the first objective to select the best mode. To change this setting:

    1. Select Optimization > Optimization Options, or click the toolbar button.

      The Optimization Options dialog box appears.

    2. Edit the setting Index to the objective to determine best mode. The default is 1, so CAGE uses the optimized values of the first objective to select the best mode. Change the index if you want to use a different objective.

    3. Click OK.

See Also