Digital signal processing of in-cylinder pressure for combustion diagnosis of internal combustion engines

In-cylinder pressure analysis is a key tool for engine research and diagnosis; however, it normally requires to process the experimental signal for providing valuable information. Usual four-step data processing consists on level correction, angle referencing, cycle averaging, and filtering. Concerning the last two issues, ad-hoc methods and experience-based algorithms are mostly used, and there is not a consensus in the scientific community about the optimal way to proceed. This paper presents a step-by-step approach to optimise the signal processing both for offline and online applications based on the characteristics of the signal.