Patent ID: 8146347

Claim:
A process for the control of charging and discharging of an oxygen reservoir of an exhaust gas catalytic converter as a function of a voltage signal of a binary lambda probe mounted downstream from the exhaust gas catalytic converter, wherein, when the voltage signal falls within a first region corresponding to a current charging state of the oxygen reservoir of the exhaust gas catalytic converter of less than approximately 30%, the method comprises: charging the exhaust gas catalytic converter until a current charging state of the oxygen reservoir of at least approximately 30% is reached; wherein, when the voltage signal falls within a second region corresponding to a current charging state of the oxygen reservoir of between approximately 30% and approximately 70%, the method comprises: finely controlling the charging and discharging of the oxygen reservoir as a function of the voltage signal to maintain the voltage signal about a lambda set point, and simultaneously subjecting the lambda setpoint to forced modulation to cause a cyclical charging and discharging of the oxygen reservoir; and wherein, when the voltage signal falls within a third region corresponding to a current charging state of the oxygen reservoir of the exhaust gas catalytic converter of greater than approximately 70%, the method comprises: discharging the exhaust gas catalytic converter until a current charging state of the oxygen reservoir of at most approximately 70% is reached, and varying the rate of charging and the rate of discharging of the oxygen reservoir of the exhaust gas catalytic converter depending on at least one factor to avoid exceeding a predefined maximum rate for charging and discharging the oxygen reservoir.