Method of dynamically estimating the fresh air flow rate supplied to an engine with high-pressure and low-pressure egr circuits

Abstract

A method of estimating fresh air flow rate entering an engine, for example a diesel engine, supercharged by a turbocharger, including at least one intake manifold of a volume, an exchanger, an air filter, a high-pressure EGR circuit, a low-pressure EGR circuit, an inlet butterfly, an exhaust butterfly, a flow meter, a pressure sensor, a temperature sensor, and a pipe between the flow meter and the inlet of the intake manifold. The method measures temperature, pressure and fresh air flow rate through the flow meter, calculates the engine flow rate, calculates the mass of gas between the flow meter and the inlet to the intake manifold, calculates the mass of gas in the manifold, measures or estimates the high-pressure EGR flow rate, calculates the flow rate of gas through the manifold, calculates the level of low-pressure EGR at the inlet manifold, calculates the mass of air between the flow meter and the inlet to the manifold, calculates the estimated level of EGR, and estimates the dynamic air flow rate from the engine flow rate and from the level of EGR at the inlet to the engine.