METHOD OF CONTROLLING THE SPARK LEAD OF AN INTERNAL COMBUSTION ENGINE

摘要

A method of controlling the spark lead (AA) of an internal combustion engine (1) having at least one cylinder (2) fitted with a spark plug (14); the method including the steps of: determining a standard spark lead (AA) value; determining an engine knock index (Ikn) in the cylinder (2); calculating a correction factor (Cf) as a function of the engine knock index (Ikn); determining a modified spark lead (AA) value by applying the correction factor (Cf) to the standard spark lead (AA) value; and controlling the spark plug (14) using the modified spark lead (AA) value. The correction factor (Cf) is calculated by statistically analysing a number of engine knock indexes (Ikn) to calculate a cumulative distribution; comparing the cumulative distribution with at least one target value (Ptarget); and modifying the current correction factor (Cf) value as a function of the comparison between the cumulative distribution and the target value (Ptarget).