Model-Based Calibration Toolbox™ 3.4

Product Description

• Introduction and Key Features
• Working with the Model-Based Calibration Toolbox
• Fitting the Model
• Calibrating the Powertrain

Fitting the Model

The Model-Based Calibration Toolbox draws on MATLAB functions for data analysis and visualization, statistics, and optimization to fit the models and generate a graphical representation of the engine's behavior. The toolbox helps you ensure that test points taken in the laboratory match the original experimental design. Using the Model Browser Tool you can then interactively fit different model types to the collected data.

Selecting Models for Engines

The Model-Based Calibration Toolbox includes a library of empirical model types for modeling engine behavior, including torque, fuel consumption, and emissions. Available models include polynomials, splines, radial basis functions, growth models, user-defined M-files, and Simulink models.

Modeling Multiple Variables

Collecting engine data often involves sweeping a single control variable while holding other variables constant—for example, sweeping spark at a given engine speed, load, and air/fuel ratio. This approach introduces two sources of variation: local (variation within tests when the spark angle is changed), and global (variation between tests when the engine speed, load, and air/fuel ratio are changed).

The Model-Based Calibration Toolbox lets you estimate local and global variations separately by fitting local and global models in two stages. You can use two-stage modeling to map the complex relationships among all the variables that control the behavior of the engine.

Engine data is collected for each test by sweeping spark while keeping speed, load, and air/fuel ratio constant. Click on image to see enlarged view.

A series of these tests is conducted, each at a different value of speed, load, and air/fuel ratio. A model is then fitted to each test (local fitting). Click on image to see enlarged view.

The local models are used to calculate global models of the engine’s behavior as speed and load vary (global fitting). Click on image to see enlarged view.

Global fitting is performed for several different aspects of engine behavior. (Images courtesy of Ford Motor Company.) Click on image to see enlarged view.