Method for detecting misfiring in an internal combustion engine by analysing the angular acceleration of the drive shaft

A method for detecting misfiring in an internal combustion engine (1) by analysing the angular acceleration (acc) of the drive shaft (4);

• the method comprising the steps of:
• estimating the value (acc) of the angular acceleration of the drive shaft (4) at predetermined angular positions of this drive shaft (4);
• comparing the absolute value (acc) of the angular acceleration of the drive shaft (4) with a predetermined threshold value (S);
• detecting the presence of a misfire if the absolute value (acc) of the angular acceleration of the drive shaft (4) is greater than the predetermined threshold value (S);
• filtering, when the presence of a misfire is detected, when an absolute value (acc) of the angular acceleration of the drive shaft (4) exceeds the threshold value (S), a set of values (acc) of the angular acceleration of the drive shaft (4) subsequent to the value (acc) of the angular acceleration of the drive shaft (4) at which the misfire has been detected to eliminate the oscillation component generated by the misfire with respect to the value (acc) of the angular acceleration of the drive shaft (4);
• and
• comparing only the filtered values (acc) of the angular acceleration of the drive shaft (4) with the threshold value (S) to detect the presence of any further misfires subsequent to the misfire detected.