Utilization of Microphone Sensors and an Active Filter for the Detection and Identification of Detonation (Knock) in a Petrol Engine

This research proposes a new method for detecting detonation (knock), that is to say the use of microphone sensors and active filters are combined with the identification of the vibration pattern of the engine sound.This is because,in terms of increasingthe fuel efficiency and power of a petrol combustion engine, the problem of detonation is a very serious issue. For this reason, the accurate, rapid and real time detection and identification of detonation also still needs to be developed. Microphone sensorsare inexpensive anddo not need to be mounted on the engine itself, meaning they are not exposed to heat, although the signal processing needs to be conducted carefully. The engine sound is recorded through a microphone and a Sallen-Key active filter is used to filter the detonation signal. Then the signal is processed to obtain the results of the regression of its function envelope. Identification is carried out using the method of calculating of the Euclidean distance of the function envelope regression from the reference signal. This is to make a determination of whether there is a detonation or not. This method is conducted with the help of Matlab. The findingsare that this method is able to detect and identify detonation signals.