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US 2022/0170400 A1Published application
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
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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.
Claims20
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 first oxygen sensor and output of a second oxygen sensor;
- and
- adjusting an amount of fuel injected to an engine via the controller according to the corrected amount of NH3 stored in the SCR.
1 more element
A system, comprising:
- an engine;
- a three-way catalyst in an exhaust system of the engine;
- a selective catalytic reductant catalyst (SCR) positioned in the exhaust system at a location downstream of the three-way catalyst;
- a sensor positioned in the exhaust system at a location downstream of the SCR;
- and
- a controller including executable instructions stored in non-transitory memory that cause the controller to generate a correction value for an amount of NH3 stored in the SCR based on a difference between an output of the sensor and an output of a NH3 storage model, and instructions to adjust the output of the NH3 storage model according to the difference and adjust an amount of fuel supplied to the engine responsive to the output of the NH3 storage model.
3 more elements
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 first oxygen sensor and an output of a second oxygen sensor;
- and
- indicating SCR degradation to a vehicle occupant or service center via the controller in response to an observer predicting NH3 slip by the second oxygen sensor switch before the first oxygen sensor switches, but where second oxygen sensor switches state after the first oxygen sensor switches state.
1 more element
Dependencies are inferred from the claim text.