Knock detection based on power spectrum analysis

A new method based on power spectrum analysis is proposed for knock detection. The method differs from the other existing methods in that the power spectrum is computed for the vibration signals every 1ms. The power spectrum is then analyzed considering the maximum value. When the maximum value of the spectrum varies among the considered segments of analysis, the current cycle is detected as a one containing knock and for the next cycle the engine is protected in order to avoid further appearances of knock.