Lookup Table Estimation
A feature calibration is the process of calibrating lookup tables by comparing an engine control unit (ECU) control or estimation algorithm implemented in Simulink® to a statistical response surface model (RSM) of measured data. The ECU software often includes algorithms for estimating states that are too difficult or costly to measure in production vehicles, such as torque and borderline spark. ECU control algorithms can require feedforward commands that initially move a system near a desired operating condition. To implement the actual control commands, including spark advance and throttle position, the ECU control algorithms use lookup tables that are functions of operating states.
The MBC Optimization app allows you to develop estimator and feedforward controller calibrations parameters graphically with Simulink block diagrams, fill the lookup tables for these parameters, and then compare the estimators with response surface models of engine behavior. Start with the Process for Calibrating and Filling Feature Tables.
Apps
| MBC Optimization | Generate optimal lookup tables for model-based calibration |
Functions
evaluateFeature | Evaluate feature in CAGE project with data set (Since R2024b) |
characterizeBattery | Characterize equivalent circuit battery in CAGE project (Since R2024b) |
exportCalibration | Export calibration items from CAGE project (Since R2024b) |
Topics
Feature Calibration Setup
- Process for Calibrating and Filling Feature Tables
Calibrate and fill feature lookup tables. - Set Up Feature and Strategy
Add a feature and import or construct a strategy. - Optimize Calibrations with Transient Controllers
Use the transient feature fill to optimize calibrations with transient controllers.
Lookup Tables
- Initialize Feature and Calibration Tables
Initialize a feature to set the values of the normalizers over the variable ranges. - Fit Data to N-D Lookup Table Using fitlookupn
Fit data to n-d lookup table using fitlookupn. - Fill Feature Lookup Tables
Initialize, fill, extrapolate, and optimize your table values. - Fill a Single Lookup Table
Fill a lookup table with measured data or from a model evaluated at the table breakpoints.
Optimization and Validation
- Calibrate a Feature for an Estimator Subsystem in an ECU
Calibrate an ECU subsystem that estimates engine torque as a function of speed, load, AFR, and spark angle.
- STEP 1: Set Up Feature and Torque Strategy
- STEP 2: Import Two-Stage Models
- STEP 3: Align Model and Feature Inputs
- STEP 4: Fill Feature and Calibration Tables
- STEP 5: Validate Feature and Export Lookup Tables
- Validate Feature Fill
Use validation data to validate the feature fill.
Battery Model Calibration
- Calibrate Powertrain Blockset and Simscape Battery Blocks
Adjust lookup tables in Simscape™ Battery™ and Powertrain Blockset™ blocks with experimental data. (Since R2023a) - Characterize Battery Equivalent Circuit Block (Code)
Characterize the Battery Equivalent Circuit block using thecharacterizeBatterymethod. - Characterize Powertrain Blockset and Simscape Battery Blocks (App)
Characterize Simulink or Simscape battery block parameters using the MBC Optimization app.
- Characterize an Equivalent Circuit Battery
Use CAGE to characterize an equivalent circuit battery.
