Mapped CI Lookup Tables as Functions of Fuel Mass and Engine Speed

The Model-Based Calibration Toolbox™ includes projects and templates that you can use to generate calibrated compression-ignition (CI) lookup tables as a function of fuel mass and engine speed. Use the tables in the Powertrain Blockset™ Mapped CI Engine (Powertrain Blockset) block.

Use Test Plan Template to Fit Models

  1. In the Model Browser, to open the data, select Import Data. Navigate to the spreadsheet that contains the data.

    For example, open matlab\toolbox\mbc\mbctraining\CiEngineData.xlsx.

    The spreadsheet contains firing and motor data collected at different engine torques and speeds.

    Firing DataDescription
    FuelMassCmd

    Commanded fuel mass, in mg

    Torque

    Engine torque, in Nm

    EngSpd

    Engine speed, in rpm

    AirMassFlwRate

    Air mass flow, in kg/s

    BSFC

    Engine brake-specific fuel consumption (BSFC), in g/kWh

    CO2MassFlwRate

    Carbon dioxide emission mass flow, in kg/s

    COMassFlwRate

    Carbon monoxide emission mass flow, in kg/s

    ExhTemp

    Exhaust temperature, in K

    FuelMassFlwRate

    Fuel mass flow, in kg/s

    HCMassFlwRate

    Hydrocarbon emission mass flow, in kg/s

    NOxMassFlwRate

    Nitric oxide and nitrogen dioxide emissions mass flow, in kg/s

    PMMassFlwRate

    Particulate matter emission mass flow, in kg/s

    Nonfiring motor data is collected at different engine speeds, without fuel consumption.

    Nonfiring DataDescription
    Torque

    Engine torque command, in Nm

    EngSpd

    Engine speed, in rpm

    AirMassFlwRate

    Air mass flow, in kg/s

  2. In the Select Sheet dialog box, select the data that you want to calibrate. For example, select Firing Data.

  3. Optionally, use the Data Editor filter the data. After you have filtered the data, close the Data Editor.

  4. In the Model Browser, select Fit Models. In the Fit Models dialog box, in the Template pane, select the template.

    For example, to fit the firing data in the spreadsheet, select MappedEngine-Fuel. Do not change the default responses and inputs.

    Fit Models dialog showing data set CEngineData and validation options. Template section highlights MappedEngine-Fuel with other options Two-Stage, MappedEngine-Nonfiring, and MappedEngine-Torque. Inputs and Responses section lists responses AirMassFlwRate, BSFC, CO2MassFlwRate, COMassFlwRate and inputs EngSpd, FuelMassCmd.

  5. Review the model fits.

    To review the response models, in the tree, select the top level.

    Interface showing All Models panel with MappedEngine-Fuel selected and a list of variables including AirMassFlwRate, BSFC, CO2MassFlwRate, and Torque. Right side displays two response model plots with black data points, orange vertical lines, and blue dashed grid lines.

    To review the response surfaces, in the tree, select the response.

    Interface showing response model CO2MassFlwRate with Gaussian Process Model type. Left panel lists variables under MappedEngine-Fuel such as AirMassFlwRate, BSFC, CO2MassFlwRate, ExhTemp, and Torque. Center panel displays response surface settings with X-axis EngSpd and Y-axis FuelMassCmd. Right panel shows a 3D surface plot with colored gradient and black data points, axes labeled EngSpd, FuelMassCmd, and CO2MassFlwRate.

Open CAGE Project

To open the project, in the CAGE Case Studies pane:

  1. Select CI Mapped Engine - Fuel Input.

  2. Click Open Example.

The project includes these tables.

NameDescriptionTable

f_air

Air mass flow, in kg/s

3D surface plot with colored gradient from blue to yellow showing relationship between FuelMassCmd and EngSpd on the X and Y axes, and a rising Z-axis value. Grid lines and data points are visible.

f_eff

Engine brake-specific fuel consumption (BSFC), in g/kWh

3D surface plot with colored gradient from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values ranging up to 700. Surface dips in the center and rises at edges.

f_co2

Carbon dioxide emission mass flow, in kg/s

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 0.03. Surface rises toward the back right corner.

f_co

Carbon monoxide emission mass flow, in kg/s

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 7×10⁻⁷. Surface rises sharply toward the back right corner.

f_texh

Exhaust temperature, in K

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 1200. Surface slopes upward toward the back right corner.

f_fuel

Fuel mass flow, in kg/s

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 0.01. Surface forms a triangular peak rising toward the back corner.

f_hc

Hydrocarbon emission mass flow, in kg/s

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 6×10⁻⁸. Surface rises toward the back right corner.

f_nox

Nitric oxide and nitrogen dioxide emissions mass flow, in kg/s

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 1.5×10⁻⁴. Surface forms a peak near the center with grid lines and black data points.

f_pm

Particulate matter emission mass flow, in kg/s

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to 0.016. Surface forms a flat plateau at the top with steep sides.

f_brake

Engine torque command, in Nm

3D surface plot with gradient colors from blue to yellow showing relationship between FuelMassCmd and EngSpd on X and Y axes, and Z-axis values up to about 300. Surface slopes upward toward the back right corner.

Use CAGE to Import and Replace Models

Use the project to import and replace existing models with new models.

  1. In CAGE, select File > Import > Model. If you do not have a model open, the model browser opens. Select a model.

  2. If your current project has two or more test plans, the Import Models dialog box prompts you to merge compatible models. Select No.

  3. The Import Models dialog box prompts you to Replace, Skip, or Create new models. Select Replace.

    Import models wizard with replace selected

After you import and replace the existing models, the Import Models wizard opens the Update Tables dialog box. You can use the Update Table dialog box to rerun optimizations and feature fills to update the tables with the new models.

Update table dialog box indicating green checks for all tables

Review and Export Lookup Tables

  1. In CAGE, review the calibrated tables.

  2. To export the tables, select File > Export > Calibration > All Items. Use the Export to parameter to specify the format. To export so that you can use the data for the Powertrain Blockset mapped engine blocks, select Simulink Model Workspace. The Model-Based Calibration Toolbox saves the mapped engine table and breakpoint data to the model workspace.

See Also

(Powertrain Blockset)

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