Examination of Methods Used to Characterize Engine Knock

A first step is taken toward the standardization of cylinder-pressure based knock-characterization methods. Toward this goal, background is presented outlining existing knock theories and providing a knock definition. Eleven methods found in the literature are described and knock data acquired and analyzed using seven of the described methods for comparison. Issues are discussed regarding identification of knocking cycles, filtering-frequency bands and effects of transducer-mounting techniques. The methods examined each had their own particular advantages and disadvantages which are summarized in the conclusions. Recommendations are provided regarding further work required to establish standard knock-characterization methods.