The method of intrinsic mode function high-frequency integral energy was proposed. In this method

the cylinder combustion pressure signals of the electronic controlled two-stroke kerosene engine were decomposed into a finite number of intrinsic mode function components and the residual function using the empirical mode decomposition method. The knock high frequency signal component was obtained by analyzing the intrinsic mode function components using the fast Fourier transform(FFT). The crank angle corresponding to the peak of the residual function peak was chosen as the starting crank angle of the knock window. Then the knock factors were calculated using the method of intrinsic mode function high frequency integral energy based on the knock high frequency signal component. By analyzing the knock window width

it's learnt is that a reasonable constant crank angle of knock window width is 30°. Knock factors of cylinder combustion pressure signals for four cycles were calculated using the method of intrinsic mode function high-frequency integral energy. Four cycles include non-knocking cycle

slight knock cycle

moderate knock cycle and strong knock cycle. The knock factors of four cycles include 0.6642

1.8191

3.0275 and 5.3717

which could represent the strength of knock. Research shows that the method of intrinsic mode function high-frequency integral energy in the process of knock factors calculation for the electronic controlled two-stroke kerosene engine is practical and effective.