System and methods for in-use NOx robustness emission control

Patent metadata

Field	Value
Publication number	US-12441295-B2
Application number	US-202318192907-A
Country	US
Kind code	B2
Filing date	Mar 30, 2023
Priority date	Mar 30, 2023
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

Methods and systems are provided for optimizing a performance of a vehicle while maintaining vehicle emissions below a threshold. In one example, a method for a controller of a vehicle comprises adjusting an operating parameter of the vehicle in response to a margin between a moving average tailpipe NOx emissions and a threshold tailpipe NOx emissions decreasing below a threshold NOx emissions margin, the moving average tailpipe NOx emissions calculated at regular intervals over a plurality of overlapping moving average windows (MAWs) of measured tailpipe NOx emissions. The threshold tailpipe NOx margin may be predicted based on expected engine-out NOx emissions of the vehicle, current NOx emissions sensitivities, and/or a predicted catalyst conversion efficiency in relation to the expected engine-out NOx emissions.

First claim

The invention claimed is:

1. A method for a controller of a vehicle, the method comprising:
adjusting an operating parameter of an engine of the vehicle in response to a margin between a moving average tailpipe NOx emissions and a threshold tailpipe NOx emissions decreasing below a threshold tailpipe NOx margin, the moving average tailpipe NOx emissions calculated at regular intervals over a plurality of overlapping moving average windows (MAWs) of measured tailpipe NOx emissions;
wherein adjusting the operating parameter further comprises one or more of:
during a motored negative acceleration of the vehicle, opening a throttle disposed at an intake passage of the engine, and closing an exhaust gas regeneration (EGR) valve of an EGR system of the engine;
restricting a tip-in response of the vehicle to reduce increases in engine-out NOx;
increasing an EGR flow rate of the engine to reduce engine-out NOx;
increasing a heat transfer from engine-out exhaust gases to a coolant at a charge air cooler and/or EGR cooler of the vehicle to reduce catalyst temperatures;
increasing transmission shift speed points to reduce brake-specific NOx emissions and/or reduce catalyst temperatures;
adjusting a torque derating curve to degrade a performance of the engine; and
switching to an engine operation mode (EOM) that reduces engine-out NOx.

2. The method of claim 1 , wherein the threshold tailpipe NOx margin is predicted based on expected engine-out NOx emissions of the vehicle, current NOx emissions sensitivities, and/or a predicted catalyst conversion efficiency in relation to the expected engine-out NOx emissions.

3. The method of claim 2 , wherein predicting the threshold tailpipe NOx margin based on the current NOx emissions sensitivities further comprises predicting the threshold tailpipe NOx margin based at least partly on:
a gross combination weight (GCW) of the vehicle;
an elevation of the vehicle;
an inclination of the vehicle; and
a route of the vehicle.

4. The method of claim 2 , wherein predicting the threshold tailpipe NOx margin based on the current NOx emissions sensitivities further comprises predicting the threshold tailpipe NOx margin based at least partly on:
a driver profile of a driver of the vehicle;
an assessment of an aggressiveness of the driver.

5. The method of claim 2 , wherein predicting the threshold tailpipe NOx margin based on the predicted catalyst conversion efficiency further comprises predicting the threshold tailpipe NOx margin based at least partly on:
a temperature of a catalyst of an aftertreatment system of the vehicle;
an age of the catalyst;
an amount of anhydrous ammonia (NH3) stored at the aftertreatment system; and
an external air temperature, pressure, and/or humidity of the vehicle.

6. The method of claim 2 , wherein predicting the threshold tailpipe NOx margin based on the current NOx emissions sensitivities further comprises:
predicting a baseline threshold tailpipe NOx margin based on the current NOx emissions sensitivities using one of a machine learning model, a rule-based system, or a statistical model;
adjusting the predicted threshold tailpipe NOx margin based on detecting a continuous high-grade region on a route of the vehicle based on global positioning service (GPS) data;
adjusting the predicted threshold tailpipe NOx margin based on a detected driver profile of the driver;
adjusting the predicted threshold tailpipe NOx margin in response to a state of charge (SOC) of a battery of the vehicle being less than a threshold SOC and a demand for torque by the driver exceeding a torque threshold.

7. The method of claim 1 , wherein the vehicle is a hybrid electric vehicle (HEV), and adjusting the operating parameter of the vehicle further comprises at least one of:
increasing a usage of a battery of the vehicle and allowing a minimum state of charge (SOC) of the battery to temporarily decrease; and
limiting an energy storage regeneration to motored negative accelerations and not regenerating directly from engine.

8. The method of claim 1 , wherein in response to a workload of an engine of the vehicle being below a threshold workload, the threshold tailpipe NOx emissions is not predicted, and the operating parameter of the vehicle is not adjusted.

9. The method of claim 1 , further comprising, in response to the margin not decreasing below the threshold tailpipe NOx margin, not adjusting the operating parameter of the vehicle, and relying on a base calibration of the operating parameter.

10. The method of claim 1 , further comprising:
predicting a probability of an amount of tailpipe NOx emissions exceeding the threshold tailpipe NOx emissions by comparing a cumulative amount of tailpipe NOx generated during an elapsed portion of each MAW of the plurality of overlapping MAWs to a time-based cumulative NOx emissions allowance for the MAW; and
detecting an increase of the probability above a first threshold probability, and in response, performing a first adjustment to the operating parameter of the engine to decrease the amount of tailpipe NOx emissions.

11. The method of claim 10 , wherein comparing the cumulative amount of tailpipe NOx generated during the elapsed portion of the MAW to the time-based cumulative NOx emissions allowance for the MAW further comprises:
plotting a cumulative measured amount of tailpipe NOx released during the MAW as a function of elapsed time, to generate a cumulative NOx emissions curve for the elapsed portion of the MAW; and
determining a probability that a projection of the cumulative NOx emissions curve over a remaining portion of the MAW intersects with a selected target NOx emissions curve for the MAW, the selected target NOx emissions curve based on expected engine-out NOx emissions of the vehicle, current NOx emissions sensitivities, and/or a predicted catalyst conversion efficiency in relation to the expected engine-out NOx emissions.

12. A method for a controller of a vehicle, the method comprising:
measuring an amount of tailpipe NOx emitted by the vehicle, at regular intervals, over a staggered set of current moving average windows (MAWs) of a fixed duration;
for each MAW of the staggered set of current MAWs, predicting a total cumulative amount of tailpipe NOx emitted by the vehicle over the MAW, based on tailpipe NOx measurements from an elapsed portion of the MAW; and
in response to the predicted total cumulative amount of tailpipe NOx exceeding a threshold amount of NOx, adjusting one or more operating parameters of the vehicle to reduce the predicted total cumulative amount of tailpipe NOx;
wherein adjusting the one or more operating parameters of the vehicle to reduce the predicted total cumulative amount of tailpipe NOx further comprises at least one of:
during a motored negative acceleration of the vehicle, opening a throttle disposed at an intake passage of an engine of the vehicle, and closing an exhaust gas regeneration (EGR) valve of an EGR system of the engine;
restricting a tip-in response of the vehicle to reduce increases in engine-out NOx;
increasing an EGR flow rate of the engine to reduce engine-out NOx;
increasing a heat transfer from engine-out exhaust gases to a coolant at a charge air cooler and/or EGR cooler of the vehicle to reduce catalyst temperatures;
increasing transmission shift speed points to reduce brake-specific NOx emissions and/or reduce catalyst temperatures;
adjusting a torque derating curve to degrade a performance of the engine; and
switching to an engine operation mode (EOM) that reduces engine-out NOx.

13. The method of claim 12 , wherein predicting the total cumulative amount of t

Assignees

• Ford Global Tech Llc

Inventors

• Polonowski Chris
• Pohlkamp Kyle
• Kurtz Eric
• Tennison Paul J

Classifications

• B60W50/0097

  Predicting future conditions · CPC title

• B60W2050/0026

  Lookup tables or parameter maps · CPC title

• B60W2510/06

  Combustion engines, Gas turbines · CPC title

• B60W2400/00

  Indexing codes relating to detected, measured or calculated conditions or factors · CPC title

• B60W2556/10

  Historical data · CPC title