Emission control in an automotive engine

A method for controlling an internal combustion engine to minimize the exhaust of a pollutant gas arising from the combustion of fuel in the engine, comprising the steps of:

• generating a plurality of command inputs for controlling the combustion of fuel in the engine;
• acquiring data from sensors indicative of operating conditions of the engine, the data including at least a first feedback variable indirectly indicative of a measure of the pollutant gas in the engine exhaust;
• determining the difference between the data for the first feedback variable to a reference value;
• applying a first formula to the difference to generate a first delta value indirectly indicative of a change in the measure of the pollutant gas as a function of a change in the first feedback variable;
• applying a second formula to the delta value to generate an open loop command value to change a pre-determined one of the command inputs to reduce the delta value;
• and
• modifying the pre-determined one of the command inputs by the open loop command value.

A method for controlling an internal combustion engine to minimize the exhaust of a pollutant gas arising from the combustion of fuel in the engine, comprising the steps of:

• determining at least two controllable engine operating parameter that when changed cause a change in a gas component of the engine exhaust;
• deriving a pre-determined relationship between changes in the operating parameters and changes in a measure of the gas component;
• sensing current engine operating conditions, including a current measure of one of the operating parameters;
• comparing the current measure of the one of the operating parameters with a pre-determined nominal value to generate a parameter delta value;
• applying the parameter delta value to the pre-determined relationship for the one of the operating parameters to obtain a gas component delta value;
• applying the gas component delta value to the pre-determined relationship for another of the at least two operating parameters to obtain a command value corresponding to a commanded change in the other operating parameter;
• and
• applying the command value to the other operating parameter provided to an engine control routine.