A method of controlling the amount of fuel delivered to an engine having at least one dedicated EGR cylinder. The method is typically performed on an engine cycle-by-cycle basis. A fueling control unit receives, from the engine's main control unit, fueling requirement data representing a current fueling requirement suitable for the main cylinders. The fueling control unit then calculates a current amount of fuel to be delivered to the dedicated EGR cylinder as a function of the number of dedicated EGR cylinders, the number of main cylinders, the current equivalence ratio for the dedicated EGR cylinder, and the fueling requirement data. With the amounts of fuel for both the dedicated EGR cylinder and the main cylinders now having been determined, the fueling control unit generates appropriate control signals to the cylinder fuel delivery mechanisms.
Jess W. Gingrich; Raphael Gukelberger; Jacob R. Zuehl