Application of Hilbert-Huang transform to engine knock detection

Knocking combustion in spark ignition (SI) engines is an undesirable mode of combustion. It causes many effects such as a rapid increase in pressure and temperature in the chamber and vibrations of the engine block. This phenomenon limits performance, durability and fuel economy and can lead to serious engine damage. The paper presents a knock detection method based on Hilbert-Huang transform (HHT). This relatively new tool allows for decomposition of a multicomponent nonstationary signal into individual components. Applying this method to the pressure signal, we are able to obtain precise information about the combustion process.