Knock Detection for SI engine Using Wavelet Transform

Abstract

The knock control has been introduced widely with a gasoline spark-ignition engine control system. Detecting knock and controlling ignition timing to allow and engine to run at the knock threshold provides the best power and fuel economy. To avoid the delay of knock detection, a technique based on the wavelet transform to detect knock in one combustion cycle is proposed in this paper. The index of knock detection is gotten with the comparison of scale power spectrum of plural resonance modes at same crank angle. The results of 4-cylinder gasoline engine examination show that this technique is may provide practical utility for real time diagnostics of combustion.