Patent ID: 6651492
Filing Date: 2003-11-25
Classification: F02D,Y02T

Abstract:
A method for determining partial air pressure in an intake manifold of an engine, such engine having an intake throttle device for controlling a flow of air to the intake manifold, an EGR valve for controlling a flow of exhaust gas from the engine to the intake manifold downstream of the intake throttle, at least one cylinder fed a flow comprising air passing through the throttle to the intake manifold and exhaust products passing through the EGR valve to the intake manifold, both the air through the throttle and the exhaust gas products in the intake manifold passing as a combined flow to the intake manifold and then to the at least one cylinder, such method comprising:estimating the flow of exhaust gas products passing through the EGR valve to the intake manifold; determining intake manifold pressure; determining air flow through the throttle device to the intake manifold; estimating the air fraction in the portion of the exhaust gas products passing to the intake manifold; combining the estimated flow of gas products, the determined intake manifold pressure, with the estimated air fraction to determine the partial air pressure in the intake manifold.