Engine speed control strategy with feedback and feedforward throttle control

A method of controlling engine speed in an internal combustion engine comprising:

• calculating a target mass flow through a throttle to produce at least one of a desired pressure or a desired density of gaseous fuel and air in an inlet manifold of the internal combustion engine;
• calculating a feedforward control term based on the target mass flow through the throttle;
• receiving data indicative of at least one of a pressure or a density of gaseous fuel and air in an inlet manifold of the internal combustion engine;
• calculating a feedback control term based on the data indicative of at least one of a pressure or a density of gaseous fuel and air in an inlet manifold of the internal combustion engine;
• and
• varying a position of the throttle based on the feedforward control term and the feedback control term such that a mass flow through the throttle is adjusted toward the target mass flow.

An internal combustion engine system comprising:

• an internal combustion engine;
• an intake system structured to convey a gaseous fuel and air to the internal combustion engine;
• a throttle;
• an engine speed control system including a sensor structured to monitor a parameter indicative of at least one of a pressure or a density of gaseous fuel and air in an inlet manifold of the internal combustion engine;
• and
• an electronic control unit coupled with the throttle and coupled with the sensor, the electronic control unit being structured to:
• calculate a target mass flow through the throttle to produce at least one of a desired pressure or a desired density of gaseous fuel and air in the inlet manifold of the internal combustion engine;
• calculate a feedforward control term based on the target mass flow through the throttle;
• calculate a feedback control term based on data produced by the sensor;
• and
• command varying a position of the throttle based on the feedforward control term and the feedback control term to adjust a mass flow through the throttle toward the target mass flow.