Patent ID: 7512479

Claim:
A method for estimating air fractions in an internal combustion engine having an intake manifold, exhaust manifold, intercooler channel, compressor input channel and a dual-loop exhaust gas recirculation system, comprising: (a) receiving information comprising pressure, temperature, mass air flow, fuel mass flow rate, exhaust gas air to fuel ratio, valve position and engine speed; (b) generating output signals based upon said information and estimating: air fraction ({circumflex over (F)} 1 ) in the intake manifold; air fraction ({circumflex over (F)} 2 ) in the intercooler channel; air fraction ({circumflex over (F)} 3 ) in the exhaust manifold; and air fraction ({circumflex over (F)} 4 ) in the compressor input channel (c) comparing at least one of said estimated air fractions to a measured air fraction; (d) determining a difference in at least one of said estimated air fractions to said measured air fraction; and (e) repeating steps (a)-(e) based upon the difference identified in step (d).