Method and system for balancing cylinder air-fuel ratio
AssigneeFord Global Technologies, LLC
InventorsDouglas Raymond Martin, Tyler Kelly, John Eric Rollinger
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for detecting cylinder-to-cylinder air-fuel ratio (AFR) imbalance in engine cylinders. In one example, a method may include detecting an AFR imbalance of an engine cylinder based on an individual crankshaft acceleration of the cylinder relative to a mean crankshaft acceleration produced by all cylinders of the engine, and correcting a fuel amount of the cylinder via a fuel multiplier value, the fuel multiplier value selected from a plurality of fuel multiplier values based on an imbalance source. In this way, the AFR imbalance may be accurately detected and correcting using existing engine system sensors.
Claims9
A method, comprising:
- detecting multiple cylinder imbalance sources;
- in response to detecting the multiple cylinder imbalance sources, isolating cylinder imbalance sources of a multi-cylinder engine;
- learning independent cylinder imbalance corrections for each of the multiple imbalance sources occurring at differing conditions of one or more of exhaust gas recirculation (EGR) and fuel vapor purge;
- and
- operating the engine with multiple of the plurality of imbalance sources occurring by blending multiple of the independent cylinder imbalance corrections based on a percentage of a total gas flow corresponding to each of the multiple of the plurality of imbalance sources.
Dependencies are inferred from the claim text.