Patent ID: 7848872
Filing Date: 2010-12-07
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. Method for controlling EGR gas flow in an internal combustion engine during ongoing operation, comprising: determining an engine operating point; determining a preferred EGR fraction for a cylinder charge based upon the engine operating point; determining a feed-forward command for controlling an external EGR gas flowrate to an engine intake manifold based upon the preferred EGR fraction for the cylinder charge; determining an intake manifold air temperature based upon an estimate of a change in the intake manifold air temperature; estimating an EGR ratio in the intake manifold based upon an intake manifold pressure, an intake air temperature, the intake manifold air temperature, and a partial air pressure in the intake manifold; and controlling the external EGR gas flowrate based upon the estimated EGR ratio in the intake manifold and the feed-forward command for controlling the external EGR gas flowrate.