Volumetric efficiency compensation for dual independent continuously variable cam phasing

摘要

A method of estimating the volumetric efficiency of an internal combustion engine having independent intake and exhaust cam phase variation, compensates a nominal or base estimate of the volumetric efficiency in two successive stages: an intake stage, and an exhaust stage. The intake stage compensates for the effects of intake cam variation, using the base volumetric efficiency estimate as a starting point; and the exhaust stage compensates for the effects of exhaust cam variation, using the output of the intake stage as a starting point. The volumetric efficiency so compensated is then used to accurately compute the mass intake airflow for engine control purposes.