METHOD AND APPARATUS FOR CONTROLLING COMBUSTION QUALITY OF A GASEOUS-FUELLED INTERNAL COMBUSTION ENGINE

A method and apparatus for controlling to a target heat release rate (HRR) uses an HRR control lever, namely, pilot fuel timing and/or pilot fuel quantity, used in a gaseous-fuelled compression ignition internal combustion engine. The mechanism to control HRR to a target HRR improves engine performance and emissions. A target HRR is determined for a cycle of an engine. An HRR control lever is then used to adjust to the target HRR in consideration of combustion conditions in the engine and the difference between the target HRR and cycle HRR predicted for the cycle by reference to, by way of example, a derived HRR trace from a previous cycle, a pressure trace, a measured property of the exhaust gas directly determined or mapped values provided during calibration allowing for adjustment to a target HRR for the engine. The mapped values can be cross-referenced to engine combustion conditions.