Patent ID: 8302381

Claim:
A method of controlling temperature of a system for post treatment of gases in an exhaust circuit of a combustion engine supplied with a mixture of which the proportion of fuel can be set according to a richer or less rich combustion mode, the exhaust circuit including at least one post treatment member in which at least one pollutant contained in the exhaust gases is trapped and stored, the method comprising: periodically subjecting the post treatment member to regeneration phases by raising the temperature of the exhaust gases to a setpoint temperature for a regeneration time to allow stored pollutants to be eliminated, a time of each regeneration phase being divided into a succession of fractionated periods, each of the fractionated periods alternating between two modes including a hotter mode for which incoming thermal power provided by the gases is greater than a setpoint power needed to obtain the setpoint temperature, and a less hot mode for which the incoming thermal power is less than the setpoint power, a duration of each period being managed so as to keep the temperature of the gases leaving the post treatment member around a mean temperature corresponding to the setpoint temperature, for each fractionated period the subjecting the post treatment member to the regeneration comprises: determining the setpoint power that the exhaust gases at an outlet from a post treatment member should provide to maintain the setpoint temperature of the exhaust gases at the outlet from the post treatment member; calculating the incoming thermal power provided by the exhaust gases at an inlet into the post treatment member; calculating an energy absorbed by the post treatment member during a fractionated period based on a difference between the thermal power provided by the exhaust gases and the setpoint power that the exhaust gases should provide to maintain the setpoint temperature, the energy absorbed being an excess of energy when the fractionated period is in the hotter mode and the energy absorbed being a deficit of energy when the fractionated period is in the less hot mode; and switching from the hotter mode to the less hot mode at an instant that an absolute value of the calculated energy absorbed by the post treatment member is equal to a predetermined maximum value and switching from the less hot mode to the hotter mode at an instant that the absolute value of the calculated energy absorbed by the post treatment member is equal to the predetermined maximum value, such that the energy excess provided in a fractioned period in the hotter mode is compensated for by the energy deficit in a next fractionated period in the less hot mode, and vice versa, to maintain the setpoint temperature.