Method for detecting detonation phenomena in an internal combustion engine

A method for detecting the development of detonation phenomena in an internal combustion engine (1) provided with a number of cylinders (2), a control unit (16), and a number of detonation sensors connected to the control unit (16);

• wherein, detonation sensors include at least one of an accelerometer and a voltage gauge which is connected and arranged in series to the electric circuit of a spark plug (15) to measure the voltage at the terminals of the electrodes of the spark plug (15) during combustion and/or a pressure gauge which measures the maximum amplitude pressure oscillation (MAPO) of the intensity of the pressure waves generated in the cylinders (2) during combustion;
• the method comprises the steps of:
• acquiring the signal (S) coming from said number of detonation sensors connected to the control unit (16);
• processing the signal (S) coming from said number of detonation sensors connected to the control unit (16) so as to obtain the detonation energy (μi) of each combustion taken into account for a given cylinder (2) and in a given engine point;
• filtering the detonation energy (μi) of each combustion taken into account for a given cylinder (2) and in a given engine point;
• calculating the mean detonation energy (μi—m) for a given cylinder (2) and in a given engine point with the filtered value of the detonation energy (μi) of each combustion taken into account for a given cylinder (2) and in a given engine point;
• comparing the detonation energy (μi) of each combustion taken into account for a given cylinder (2) and in a given engine point with the mean detonation energy (μi—m) for a given cylinder (2) and in a given engine point;
• determining the variance (σi) of each combustion taken into account for a given cylinder (2) and in a given engine point as a function of the comparison between the detonation energy (μi) of each combustion taken into account for a given cylinder (2) and in a given engine point and the mean detonation energy (μi—m) for a given cylinder (2) and in a given engine point;
• calculating the maximum variance (σi—max) for a given cylinder (2) and in a given engine point with a reduction of the spark advance actuated in the given cylinder (2);
• comparing the maximum variance (σi—max) for a given cylinder (2) and in a given engine point with the variance (σi) of each combustion taken into account for a given cylinder (2) and in a given engine point;
• and
• determining the development of detonation phenomena for each combustion taken into account for a given cylinder (2) and in a given engine point as a function of the comparison between the maximum variance (σi—max) for a given cylinder (2) and in a given engine point and the variance (σi) of each combustion taken into account for a given cylinder (2) and in a given engine point.