Cylinder charge composition observation based on in-cylinder pressure measurement

Accurate cylinder charge and composition estimation is crucial for proper combustion control, however, current sensors and models show different issues for transient estimation. The work presented in this paper combines a novel technique for trapped mass estimation, which relies on the in-cylinder pressure resonance, with on-board engine sensors by taking into account the intake manifold dynamics with a closed-loop observer. The resonance method provides a measurement of trapped mass with one cycle resolution. This measurement feeds a Kalman filter to improve the transient and steady response of the intake charge and composition estimation. The observer was validated in a four stroke heavy-duty engine, showing fast transient capabilities and an adequate steady-state accuracy.