Method and apparatus for controlling operation of an internal combustion engine

A method for operating an internal combustion engine, the method comprising:

• determining a motored-cylinder temperature based upon an engine operating point in response to an operator request for power;
• determining a knock-limited combustion phasing point based upon the motored-cylinder temperature;
• selecting engine operating parameters associated with achieving the knock-limited combustion phasing point;
• controlling, by a controller, engine control states to achieve the engine operating parameters associated with achieving the knock-limited combustion phasing point for the engine operating point that is in response to the operator request for power;
• and
• evaluating, by a controller, deterioration in engine performance based upon the knock-limited combustion phasing point, the motored-cylinder temperature and the engine operating point.

An internal combustion engine, comprising:

• a multi-cylinder four-stroke internal combustion engine having reciprocating pistons slidably movable in cylinders that define variable volume combustion chambers, a plurality of actuators and a plurality of sensors;
• a controller including executable routines, the routines including:
• determining a motored-cylinder temperature based upon an engine operating point in response to an operator request for power,
• determining a knock-limited combustion phasing point based upon the motored-cylinder temperature,
• selecting engine operating parameters associated with achieving the knock-limited combustion phasing point, and
• controlling engine control states to achieve the engine operating parameters associated with achieving the knock-limited combustion phasing point for the engine operating point that is responsive to the operator request for power.