Abstract
Keywords: calibration, model based, optimization
The growing complexity of modern internal combustion engines control systems, the time to market reduction and the need for robust and multi objective performance, can only be handled with the evolution of the engine calibration process.
In this work a general purpose, model based, calibration methodology will be described, melting statistic concepts, like Design Of Experiments and Robust Design, numerical optimization techniques and ECU algorithms modelling. The described approach uses software tools developed in Matlab environment, in order to assist in the calibration of estimation algorithms used in the Engine Control Unit. The developed tools are:
- non linear multivariable regression;
- discrete regression;
- multi map optimization
- graphical user interface for calibration verification and modification;
- calibration performance meter.
This approach has been applied to the base engine calibration process of the last FIAT gasoline engines: Fire EVO 2 1.4l /1.2l, STARJET 1.4l 16v (all these engines are equipped with continuously variable cam phaser), and Turbo 1.4l 16v 155 Cv. With base-engine calibration it is intended the calibration activity that deals with algorithms involved in the engine operation, not dependent on a particular vehicle application, like charge estimation, injector model, spark advance calculation, torque estimation, catalyst protection and so on.