System and method controlling engine based on predicated engine operating conditions

A method for controlling an engine coupled to an emission control device through which exhaust gases flow, the method comprising:

• predicting whether future vehicle operating conditions may result in a change of an oxidant to reductant ratio of the exhaust gas even though a desired air-fuel ratio is maintained;
• in response to said prediction, adjusting a set-point amount of oxidant stored in the emission control device to prevent said change from causing an actual amount of stored oxidants to fall outside a predetermined range, said adjusting comprising lowering said oxidant set-point when it is predicted that future operating conditions will have a higher oxidant to reductant ratio, and increasing said oxidant set-point when it is predicted that future operating conditions will have a lower oxidant to reductant ratio;
• and
• adjusting an engine air-fuel ratio fed to the engine based on said adjusted set-point.

A computer storage medium having a computer program encoded therein controlling an engine coupled to an emission control device through which exhaust gases flow, the computer storage medium comprising;

• code for predicting whether future vehicle operating conditions may result in a change of an oxidant to reductant ratio of the exhaust gas based on measured vehicle operating condition even though a desired air-fuel ratio is maintained, said measured vehicle operating condition including at least one of a vehicle speed, an engine speed, a throttle position, and an engine airflow;
• code for adjusting a set-point amount of oxidant stored in the emission control device to prevent said change from causing an actual amount of stored oxidants to fall outside a predetermined range;
• and
• code for adjusting an engine fuel injection amount based on said adjusted set-point, said adjustment reducing said actual amount of oxidants stored when said prediction indicates a higher oxidant to reductant ratio and increasing said actual amount of oxidants stored when said prediction indicates a lower oxidant to reductant ratio.

A method for controlling an engine coupled to an emission control device, the method comprising:

• predicting whether future vehicle operating conditions may result in either a rich or lean excursion, said prediction being based in part on a measured operating parameter read from a sensor coupled to the vehicle;
• in response to said prediction, adjusting a set-point amount of oxidant stored in the emission control device to prevent said rich or lean excursion from causing an actual amount of stored oxidants to fall outside a predetermined range;
• and
• adjusting a fuel injection amount into the engine based on said adjusted set-point, said adjusting comprising increasing said fuel injection amount in response to said predicted lean excursion and decreasing said fuel injection amount in response to said predicted rich excursion.