Detection of Knock Location by Multipoint Pressure Measurement

Abstract

An algorithm to detect knock location was developed, utilizing differences in the arrival time of the pressure wave caused by knocking between 5 pressure sensors in the combustion chamber of a gasoline engine. In this algorithm, the time differences were derived from time-frequency analysis of the Fourier spectrum with an accuracy of several μs. Furthermore, calculation of knock location by the least square method correlated with the results of the experiment with minimum error. It was applied under certain conditions in a single cylinder engine, and knock locations were determined for both homogeneous and stratified combustion.