Air Path Model for Gasoline Engines with Fully Variable Valvetrain Systems Methodology Tools for Cost-Efficient Calibration

摘要

The Schaeffler UniAir system allows an unprecedented unmatched level of freedom inthe engine valve lift control. This high degree of flexibility requires changes in the enginecontrol system. For example, the capability to control different valve lifts in eachcylinder and every engine revolution enables th e use of the air path to manage fasttorque variations, keeping the spark advance in the optimal position with consequentCO_2 and engine raw emission reduction. To manage the high dynamic response of theair, it is necessary to implement a feed forward model in the engine control software(ECM) able to predict the air and EGR trapped in the cylinders with high precision. Thisarticle shows a flexible physical based air and EGR prediction model combined with atool for the physical based model calibration to minimize the engine calibration effort.