Prediction of Knock Sensor Locations with Background Noise

This paper presents an analytical approach to predict knock sensor locations with the consideration of background noise in align with current accelerometer based knock detection techniques.

Finite element (FE) based forced frequency response analysis is used to estimate the paths in engine structure for the propagation of dynamic energy generated by both combustion knock pressure and engine background noise sources. The analysis is performed with the consideration of the facts that, within interested frequency range, knock pressure, background noise sources, and even the accuracy of FE simulation, are uncertain or cannot be described precisely. Distributions for both knock sensitivity and CAE signal to noise ratio are obtained as results and used to predict the optimal knock sensor locations. Good correlation with testing results is observed.