Engine knock recognition based on ARMA model high frequency

This research is based on spark ignition(SI)engine combustion test bench,in which,the ignition advance angle of the engine be changed to get high knock intensity load cases.10° and 20° crank angle before and after low-pass combustion pressure peak value was selected as knock sensitive window(KSW).ARMA time serial model was chosen to simulate high-frequency vibration signal of a bench of KSW.Mahalanobis distance of vector,created by mean value of ARMA model's parametric,was selected to indentify knock phenomenon.Threshold value,designed by Monte-Carlo approach on mahalanobis distance of non-engine knock cycles,is suitable to indentify knock case,and was tested by experiment data from SI engine combustion test.The feasibility of this method was verified by VDO method,which was widely used in engineering.