Engine feedback control system and method

A single-input-single-output (SISO) control system for an internal combustion engine, comprising:

• a selection module configured to select, for an operating point, one operating parameter lever and one emissions characteristic, said operating parameter lever related to one of exhaust gas recirculation (EGR) fraction and charge air mass flow (MCF);
• a reference retrieving module adapted to retrieve a stored pre-calibrated reference value associated with the selected emissions characteristic, said pre-calibrated reference value based on predetermined reference data associated with a respective operating point of the internal combustion engine;
• a difference calculating module adapted to receive a signal corresponding to a measured value of the emissions characteristic and calculate a difference between the pre-calibrated reference value and the measured value;
• a controller adapted to provide a control signal based on the calculated difference;
• and
• an operating parameter adjustment module adapted to receive the control signal, determine an adjustment factor value based on the control signal and the operating point, retrieve a stored operating parameter reference value related to selected operating parameter lever for the respective operating point, and adjust the value of the stored operating parameter reference value by an amount based on the adjustment factor value.