US 11,725,603 B1
Systems and methods for air-fuel ratio imbalance monitor
Michael Uhrich, Wixom, MI (US); Mario Santillo, Canton, MI (US); Joseph Lyle Thomas, Farmington Hills, MI (US); and Stephen William Magner, Farmington Hills, MI (US)
Assigned to Ford Global Technologies, LLC, Dearborn, MI (US)
Filed by Ford Global Technologies, LLC, Dearborn, MI (US)
Filed on Mar. 7, 2022, as Appl. No. 17/653,729.
Int. Cl. F02D 41/14 (2006.01); F01N 13/00 (2010.01); F02D 41/38 (2006.01); F01N 11/00 (2006.01); F01N 9/00 (2006.01)
CPC F02D 41/1454 (2013.01) [F01N 13/008 (2013.01); F02D 41/1441 (2013.01); F02D 41/38 (2013.01); F01N 9/005 (2013.01); F01N 11/007 (2013.01); F01N 2560/02 (2013.01); F01N 2560/027 (2013.01); F01N 2560/14 (2013.01); F01N 2900/04 (2013.01); F01N 2900/0402 (2013.01); F01N 2900/0408 (2013.01); F01N 2900/0411 (2013.01); F01N 2900/0412 (2013.01); F01N 2900/0416 (2013.01); F01N 2900/06 (2013.01); F01N 2900/1402 (2013.01)] 17 Claims
OG exemplary drawing
 
1. 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.
 
7. 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.