Combustion state determining a method in the case of an internal combustion engine as well as combustion state control method and combustion state control system for an internal combustion engine

摘要

A combustion control apparatus for a lean-burn engine is mounted on an automobile, etc., and is directed to make reliable combustion control in consideration of probable and statistic properties of combustion fluctuation. The apparatus includes means (107) for detecting variations of the angular acceleration of the shaft driven by an engine (1), means (102) for normalizing the detected variations in accordance with the operating condition of the engine (1), means (104) for comparing the normalized variations with a predetermined threshold value to obtain a combustion deterioration judgement value, and control means (105) for comparing the combustion deterioration judgement value with a predetermined reference value and controlling a combustion regulation (106) of the engine (1) so that the combustion deterioration judgement value approaches the reference value.