Patent ID: 6588210
Filing Date: 2003-07-08
Classification: F02B,F02D,G01F,Y02T

Abstract:
A method for measuring the mass flow rate of recirculated exhaust gas in a vehicle having a compression-ignition engine, a plurality of engine sensors having outputs indicative of current engine conditions including an intake manifold pressure sensor, and a variable geometry turbocharger in which geometry is varied by a controllable actuator, the method comprising:sensing intake manifold pressure; controllably diverting a selected portion of exhaust gas for mixture with intake air; sensing temperature in a flow of the recirculated exhaust gas; obstructing the flow of the recirculated exhaust gas; sensing pressure of the recirculated exhaust gas downstream of the obstruction; sensing pressure of the recirculated exhaust gas upstream of the obstruction; and determining flow rate of the recirculated exhaust gas as a function of the intake manifold pressure, recirculated exhaust gas temperature, and differential pressure drop across the obstruction.