An Event-Based Transient Fuel Compensator with Physically Based Parameters

An event-based transient fuel compensator (TFC) algorithm was developed for production application on SPFI gasoline engines.

The independent parameters of the TFC were related to fundamental mass-transfer principles from the research of Gilliland and Sherwood [1] to simplify cold-driveability and emissions calibration activities. A compact intake valve temperature model was developed to further simplify calibration. Digital Control Theory was applied to the calibration structure of the algorithm to clarify the relationship between compensator stability and parameter settings.

In its final production algorithm form on a 2.4L DOHC engine application, the TFC met the required subjective cold-driveability requirements and emission standards with a significant reduction in transient fuel calibration complexity.