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US 11,725,603 B1Granted
Systems and methods for air-fuel ratio imbalance monitor
AssigneeFord Global Technologies, LLC
InventorsMichael Uhrich, Mario Santillo, Joseph Lyle Thomas, Stephen William Magner
Life of this patent
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Abstract
Methods and systems are provided for an exhaust system. In one example, a method may include determining presence of a zone flow based on a comparison of a first exhaust sensor and a second exhaust sensor. The presence or absence of the zone flow may determine a rate at which an air-fuel ratio is adjusted.
Claims17
A method, comprising:
- determining presence of a zone flow in an aftertreatment system coupled to an engine in response to a difference between feedback from a first exhaust sensor and a second exhaust sensor, the first exhaust sensor is upstream of the second exhaust sensor, the first exhaust sensor is arranged in a gap in a catalyst housing between a first catalyst and a second catalyst.
An outer loop air-fuel control system, comprising:
- a catalyst housing comprising a first catalyst and a second catalyst;
- a first exhaust sensor positioned in a mid-bed region in between the first catalyst and the second catalyst;
- a second exhaust sensor positioned downstream and outside of the catalyst housing;
- a proportional controller configured to control an air-fuel ratio based on signals received from the first exhaust sensor;
- an integral controller configured to control the air-fuel ratio based on signals received from the second exhaust sensor;
- and
- a controller with computer-readable instructions stored thereon that when executed enable the controller to:
- determine a presence of a zone flow based on a difference between feedback from the first exhaust sensor and the second exhaust sensor, the controller coupled to each of the proportional controller and the integral controller;
- and
- signal to a fuel injector based on signals generated via only the proportional controller in response to the zone flow being absent.
7 more elements
A method, comprising:
- determining presence of a zone flow of an aftertreatment system coupled to an engine in response to a difference between feedback from a first exhaust sensor and a second exhaust sensor, wherein the first exhaust sensor is upstream of the second exhaust sensor, the first exhaust sensor is arranged in a gap in a catalyst housing between a first catalyst and a second catalyst;
- and
- adjusting an air-fuel ratio at a first threshold rate based on feedback from only the first exhaust sensor in response to the zone flow being absent.
Dependencies are inferred from the claim text.