Rumble type abnormal combustion detecting method for cylinder of spark ignition engine, involves determining whether self-ignition is occurred or not based on difference between stored values and threshold, for given cycle

摘要

The method involves measuring instantaneous internal pressure (Pcyl) of a cylinder for a cycle of an internal combustion engine i.e. spark ignition engine. A set of determined values is stored in a memory based on the measured cylinder pressure, where each stored value is a value of maximum pressure (Pmax) of the cylinder and an initiation delay. The stored values are compared with a predetermined threshold whose value is constant in time. Determination is made whether self-ignition is occurred or not based on a difference between the stored values and the threshold, for a given cycle.