Detection of knocking for spark ignition engines based on structural vibrations

A new method to detect knocking of combustion engines is discussed. It uses a signal model for the knocking which consists of a sum of damped sinusoids with time-shifting frequencies generated by cavity resonance oscillations of the gas in the combustion chamber. The model is verified with a real knocking signal. Finally, a traditional method, the simple energy detector, is compared with the new approach by using the estimated receiver operation characteristic.