Abstract: A system and method for controlling an internal combustion engine to improve air/fuel ratio control using a feed-forward observer-based control strategy include estimating current and future airflow actuator positions, determining corresponding mass airflow values, and determining a future in-cylinder air charge based on a difference between the current and future mass airflow values. In one embodiment, the difference between current and future mass airflow estimates is used as a feed-forward term and combined with a sensed or measured value generated by a mass airflow sensor prior to being processed using a manifold filling model to predict the future cylinder air charge.

Abstract: A system and method for controlling an internal combustion engine to improve air/fuel ratio control particularly during transient operating modes include estimating cylinder air charge during a future fuel injection event. The system and method use a dynamic airflow actuator position model to determine future actuator position which is then used by an airflow model and manifold filling model to provide the estimated future cylinder air charge. The system and method use observer-based and adaptive control to compensate for modeling errors and sensor dynamics while assuring stability and accurate prediction of airflow actuator position and airflow.