State-based diesel fueling for improved transient response in dual-fuel engine

A controller for controlling the amount of diesel fuel delivered to a dual-fuel internal combustion engine, the engine being fueled with both gaseous fuel and diesel fuel, and the engine having a conventional engine control unit, comprising:

• a processor and memory system programmed to perform the following tasks:
• to receive a signal from the operator of the engine representing a desired torque;
• to determine a desired intake manifold pressure and a desired intake manifold oxygen fraction, based on the desired torque;
• to control flow actuators for at least the intake air flow and the intake gaseous fuel such that the desired intake manifold pressure and desired intake manifold oxygen fraction will occur;
• to receive sensor data from which the engine speed and a current in-cylinder state can be measured or estimated;
• wherein the current in-cylinder state comprises at least an in-cylinder amount of gaseous fuel and an in-cylinder amount of oxygen;
• to determine a current amount of diesel fuel based at least on the desired torque, the engine speed and the current in-cylinder state;
• and to generate a diesel fueling command representing the current amount of diesel fuel.