Method for determining the rate of recirculated exhaust gas at the inlet of a cylinder of an internal combustion engine, and engine implementing such a method

19:

• The method as claimed in claim 18, wherein in c), the method comprises identifying the required EGR rate at the inlet of the cylinder at the moment t with the EGR rate at the outlet of the recirculation duct at the preceding moment t_int.ro as determined in b).

The method as claimed in claim 20, wherein in a4), the method comprises determining the moment tjntro as the moment at which the total mass of gas contained in the intake line at the moment t, as determined in a1), is closest to the total mass of gas fed into the intake line at the outlet of the recirculation duct since each moment until the moment t, as determined in a2).

The method as claimed in claim 20, wherein in a4), the method comprises determining the moment tjntro as the moment tj at which the total mass of gas contained in the intake line at the moment t, as determined in a1), becomes greater than the total mass of gas fed into the intake line at the outlet of the recirculation duct since each moment tj until the moment t, as determined in a2).

The method as claimed in claim 20, wherein in b), the method comprises:

• b1) determining and memorizing the EGR rate at the outlet of the recirculation duct at each moment tj;
• b2) determining the EGR rate at the outlet of the recirculation duct at the moment tjntro on the basis of the EGR rate at the outlet of the recirculation duct, as determined in b1), for the moment tj nearest to the moment tjntro.

The method as claimed in claim 20, wherein in a1), the method comprises determining an elementary mass of gas fed into the intake line at the outlet of the recirculation duct at each successive moment preceding the moment t on the basis of a total flow rate of gas pumped by a compressor fitted on the intake line downstream of the outlet of the recirculation duct.

The method as claimed in claim 20, wherein in a3), the method comprises determining a mass of gas contained in the intake line at the moment t on the basis of a volume of the intake line between the outlet of the recirculation duct and the inlet of the cylinder, and on the basis of a temperature and pressure of the gas circulating in the intake line at the moment t.

An internal combustion engine of a motor vehicle comprising:

• an intake line supplying intake gas to at least one cylinder of the engine and an exhaust line conveying the exhaust gas after its combustion in the cylinder;
• a portion of the exhaust gas being recirculated in a recirculation duct connecting the exhaust line of the engine to the intake line;
• an electronic control unit programmed to determine a rate of recirculated exhaust gas, as the EGR rate, at the inlet of the cylinder at a moment t, in accordance with the method as claimed in claim 18.