Verfahren zur Regelung der Abgastemperatur in einer Brennkraftmaschine

摘要

A method of controlling an exhaust gas temperature of an internal combustion engine 12 during low engine speeds and low engine load conditions is provided. The method includes the step 68 of calculating a target engine operational parameter responsive to an air/fuel ratio of the engine 12 and an engine speed error. The target engine operational parameter is one the following parameters: a target intake manifold pressure, a target intake manifold mass air flow, or a target air/fuel ratio. The method further includes the step 98 of calculating a commanded position for a throttle valve 18 disposed in an intake manifold 16 of the engine 12. The commanded position is calculated responsive to the target engine operational parameter and a measured engine operational parameter. The measured engine operational parameter is one of the following parameters: a measured intake manifold pressure, a measured intake manifold mass air flow, or a measured air/fuel ratio. The method further includes the step 138 of controlling the throttle valve 18 responsive to the commanded position to control the exhaust gas temperature of the engine 12. The method further includes the step 140 of setting a commanded engine speed to a predetermined speed to further control the exhaust gas temperature. Finally, the method includes the step 142 of injecting a predetermined amount of fuel into one of the cylinders 44 of the engine 12 late in a power stroke of the one or more cylinders 44 to further control the exhaust gas temperature.