CAGE User's Guide

What Are Feature Calibrations?

The feature calibration process within the Model-Based Calibration Toolbox calibrates an estimator, or feature, for a control subsystem in an electronic control unit (ECU). These features are usually algebraic collections of one or more tables. You use the features to estimate signals in the engine that are unmeasurable, or expensive to measure, and are important for engine control. The toolbox can calibrate the ECU subsystem by directly comparing it with a plant model of the same feature.

An example of an ECU subsytem control feature estimates the value of torque, depending on the four inputs: speed, load, air-fuel ratio (AFR), and spark angle.

A diagram of this ECU subsystem example follows.

In this example, there are three lookup tables:

• A speed-load table
• A modifier, or table, for AFR
• A modifier for spark angle

This tutorial takes you through the various steps required to set up this feature and then calibrate it using CAGE.

Feature Calibration Tutorial

Setting Up Calibrations