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US 11,603,787 B2Granted
Methods and system for controlling selective catalytic reductant catalyst of a gasoline engine
AssigneeFord Global Technologies, LLC
InventorsMichiel J. Van Nieuwstadt, Michael Uhrich, Timothy R. Gernant, Giovanni Cavataio, Joseph Thomas
Life of this patent
Estimating the term…
Abstract
Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH3 that is stored in a SCR. The amount of NH3 that is stored in the SCR is a basis for generating additional NH3 or ceasing generation of NH3.
Claims12
A method for operating an engine, comprising:
- estimating an amount of NH3 stored in a selective catalytic reductant catalyst (SCR) via a controller;
- correcting the amount of NH3 stored in the SCR via the controller in response to output of a first oxygen sensor and output of a second oxygen sensor, where correcting the amount of NH3 stored in the SCR includes integrating a difference between the output of the first oxygen sensor and the output of the second oxygen sensor, where correcting the amount of NH3 stored in the SCR includes adjusting an amount of NH3 stored in the SCR based on a difference between an estimated NH3 slip and modeled NH3 slip, where the estimated NH3 slip is based on a slip time or a slip area, and where the modeled NH3 slip is based on exhaust flow, a temperature of the SCR, and a Lambda value;
- and
- adjusting an amount of fuel injected to the engine via the controller according to the corrected amount of NH3 stored in the SCR.
1 more element
A method for operating an engine, comprising:
- estimating an amount of NH3 stored in a selective catalytic reductant catalyst (SCR) via a controller;
- correcting the amount of NH3 stored in the SCR via the controller in response to an output of a first oxygen sensor and an output of a second oxygen sensor, where correcting the amount of NH3 stored in the SCR includes adjusting an amount of NH3 stored in the SCR based on a difference between an estimated NH3 slip and modeled NH3 slip, where the estimated NH3 slip is based on a slip time or a slip area, and where the modeled NH3 slip is based on exhaust flow, a temperature of the SCR, and a Lambda value;
- and
- indicating SCR degradation to a vehicle occupant or service center via the controller in response to an observer predicting NH3 slip.
1 more element
Dependencies are inferred from the claim text.