Calibrate a Feature for an Estimator Subsystem in an ECU

This example shows how to calibrate the electronic control unit (ECU) subsystem feature model. The feature model estimates the spark-ignition (SI) engine torque, T, as a function of speed, N, load, L, air-to-fuel ratio, AFR, and delta spark angle, S.

In this example, three lookup tables represent an ECU subsystem.

Plant model for torque diagram. Speed and load input for maximum brake torque. Air to fuel ratio input for efficiency multiplier. Delta spark angle input for efficiency multiplier. Maximum brake torque, air fuel ration multiplier, and spark efficiency multiplier all multiplied to produce torque.

This table shows a workflow for calibrating an ECU subsystem.

Step

Description

1

Set Up Feature and Torque Strategy

Create the feature and import the strategy from a Simulink® model file. In this example, the strategy represents torque as the product of three lookup tables:

  • Maximum brake torque (MBT)

  • AFR efficiency multiplier

  • Spark efficiency multiplier

2

Import Two-Stage Models

Use CAGE to import these two-stage statistical models:

  • Torque as a function of engine spark angle, engine load, engine speed, and AFR

  • Spark at MBT as a function of engine load, engine speed, and AFR

3

Align Model and Feature Inputs

To align the statistical model with the feature inputs, create function models.

4

Fill Feature and Calibration Tables

Fill the feature so that torque table, T, represents the torque at standard conditions where the engine operates most of the time.

5

Validate Feature and Export Lookup Tables

Use validation data to validate the feature fill. Export the calibrated tables.

See Also

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