Feed-forward observer-based control for estimating cylinder air charge

摘要

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. In another embodiment, the current and future mass airflow estimates are processed using the manifold filling model with the results used to generate a future delta cylinder air charge that is subsequently used as a feed-forward term and combined with a measured air charge corresponding to a measured mass airflow processed by the manifold filling model.