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Mapped SI Lookup Tables as Functions of Engine Torque and Speed

The Model-Based Calibration Toolbox™ includes a project and template that you can use to generate calibrated spark-ignition (SI) lookup tables as a function of engine torque and speed. Use the tables in the Powertrain Blockset™ Mapped SI 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\SiEngineData.xlsx.

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

    Firing DataDescription
    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-Torque. Do not change the default responses and inputs.

    Fit Models dialog showing data set SIEngineData, validation options, and percentage for validation. Template section displays Two-Stage, MappedEngine-Nonfiring, and MappedEngine-Torque with the last option highlighted. Inputs and Responses section lists responses AirMassFlwRate, BSFC, CO2MassFlwRate and inputs EngSpd, Torque. Data channels panel is empty.

  5. Review the model fits.

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

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

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

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

Open CAGE Project

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

  1. Select SI Mapped Engine - Torque Input.

  2. Click Open Example.

The project includes these tables.

NameDescriptionTable

f_air

Air mass flow, in kg/s

3D surface plot showing a rising gradient from blue at the lower left to yellow at the upper right, representing a function of Torque (x-axis) and Engine Speed (y-axis) versus an output value (z-axis).

f_eff

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

3D surface plot showing a curved gradient from blue to yellow, representing a function of Torque (x-axis) and Engine Speed (y-axis) versus an output value (z-axis) with a dip in the center and rising edges.

f_co2

Carbon dioxide emission mass flow, in kg/s

3D surface plot with a rising gradient from blue at the base to yellow at the peak, showing a function of Torque (x-axis) and Engine Speed (y-axis) versus a small-scale output value (z-axis).

f_co

Carbon monoxide emission mass flow, in kg/s

3D surface plot with a steep peak in yellow and flat blue base, showing Torque (x-axis) and Engine Speed (y-axis) versus a small-scale output value (z-axis).

f_texh

Exhaust temperature, in K

3D surface plot with a dip near the origin and higher yellow regions toward the edges, showing Torque (x-axis) and Engine Speed (y-axis) versus output value (z-axis).

f_fuel

Fuel mass flow, in kg/s

3D surface plot with a smooth peak in yellow and base in blue, showing Torque (x-axis) and Engine Speed (y-axis) versus a small-scale output value (z-axis).

f_hc

Hydrocarbon emission mass flow, in kg/s

3D surface plot with a sharp peak in yellow and flat blue base, showing Torque (x-axis) and Engine Speed (y-axis) versus a very small-scale output value (z-axis).

f_nox

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

3D surface plot with a moderate peak in yellow and broad blue base, showing Torque (x-axis) and Engine Speed (y-axis) versus a very small-scale output value (z-axis).

f_pm

Particulate matter emission mass flow, in kg/s

3D surface plot showing a flat teal plane at zero across Torque and Engine Speed axes.

f_brake

Engine torque command, in Nm

3D surface plot with a sloped gradient from blue at the base to yellow at the top, showing Torque (x-axis) and Engine Speed (y-axis) versus output value (z-axis).

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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