Control system for an engine with egr flow

A method of controlling an internal combustion engine, comprising:

• determining a maximum fuel injection flow rate based on a first group of operating parameters associated with the engine;
• determining a maximum EGR flow rate based on a second group of operating parameters associated with the engine;
• receiving a fuel injection flow request and an EGR flow request;
• setting the current fuel injection flow rate to the maximum fuel injection flow rate if the fuel injection flow request is greater than the maximum fuel injection flow rate;
• and
• setting the current EGR flow rate to the maximum EGR flow rate if the EGR flow request is greater than the maximum EGR flow rate, wherein
• the maximum fuel injection flow rate and the maximum EGR flow rate are determined in a closed-loop manner, and the first and second groups each comprise an oxygen-to-fuel ratio limit determined based on a speed of the engine.

A method of calibrating an internal combustion engine, comprising:

• determining a current oxygen-to-fuel ratio associated with the engine;
• determining maximum and minimum oxygen-to-fuel ratio limits based on a current speed of the engine;
• and
• modifying a group of engine settings based on at least one of the following relationships:
• a first set of known relationships associated with steady state emissions conditions, in response to determining that the current oxygen-to-fuel ratio is greater than the maximum oxygen-to-fuel ratio limit;
• and
• a second set of known relationships associated with acceleration state emissions conditions, in response to determining that the current oxygen-to-fuel ratio is less than the minimum oxygen-to-fuel ratio limit.