Method and apparatus for detecting combustion conditions in multicylinder internal combustion engine based upon engine speed evaluation

摘要

A method and apparatus for detecting the quality of combustion in each cylinder of a multi-cylinder internal combustion engine is disclosed. The invention determines a combustion stroke of each cylinder by sensors and detects the rotational speed of the engine at least three times during each combustion stroke by a rotation speed calculation device. The detected rotational speeds are evaluated by an arithmetic calculation device to identify the variation in rotational speed of each piston during a combustion stroke whereby the quality of combustion is, thus, determined. In a feature of the invention fluctuations in rotational speed caused by reciprocating inertia (&ohgr;.sub.c) are calculated and eliminated from fluctuation in engine speed caused by combustion (&ohgr;. sub.g) so that the quality of combustion based only upon variation in detected speeds caused by combustion is derived.