Estimation of In-Cylinder Pressure for Advanced Combustion Engines

Cylinder pressure is one of the most important parameters that characterize the combustion process in an internal combustion engine. Recent developments in engine control technologies suggest the use of cylinder pressure as a feedback signal for closed-loop combustion control. However, the sensors measuring in-cylinder pressure are typically subject to noise and o®set issues, requiring signal processing methods to be applied to obtain a su±ciently accurate pressure trace. The signal conditioning implies a considerable computational burden, which ultimately limits the use of cylinder pressure sensing to laboratory testing, where the signal can be processed online. In order to enable closed-loop combustion control through cylinder pressure feedback, several real-time estimation algorithms are proposed herein to extract the pressure signal from the in-cylinder production grade sensor. The estimators were derived analytically and proofs of stability are provided.