Patent ID: 7267117

Claim:
A device for controlling the exhaust gas recirculation in an internal-combustion engine, said engine being provided with an air-intake system, a gas-exhaust system, and an exhaust-gas-recirculation system; said device comprising measuring means for measuring the oxygen concentration in the air/recirculated-exhaust-gas mixture taken in by the engine; and control means connected to said measuring means and to the exhaust-gas-recirculation system for controlling the exhaust gas recirculation on the basis of The oxygen concentration in the mixture taken in by the engine said control means comprising means for calculating the concentration of recirculated exhaust gases (% EGR) in the mixture taken in by the engine as a function of the oxygen concentration in the mixture itself, in particular according to the following equation: % ⁢ ⁢ EGR = 1 - % ⁢ ⁢ O 2 , air + EGR % ⁢ ⁢ O 2 , air wherein % O 2,air is the oxygen concentration in the air and % O 2,air+EGR is the oxygen concentration in the mixture taken in; and wherein said control means implements a closed-loop control of the exhaust gas recirculation based on the concentration of recirculated exhaust gases (% EGR) in the mixture taken in by the engine.