Reductant dosing correction during no dosing periods

Patent metadata

Field	Value
Publication number	US-2016369677-A1
Application number	US-201615184584-A
Country	US
Kind code	A1
Filing date	Jun 16, 2016
Priority date	Jun 18, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

A system may include a NO x sensor and a controller. The controller may be configured to interpret a value of a first parameter indicative of an amount of NO x measured by the NO x sensor and interpret a value of a second parameter for a NO x value from a look-up table. The controller may be further configured to determine a correction factor based on the value of the first parameter and the value of the second parameter and generate a dosing command based, at least in part, on the determined correction factor. In some implementations, the NO x value from the look-up table may be based on one or more operating conditions of an engine. In some implementations, the controller may be further configured to update a NO x value of the look-up table based on the determined correction factor.

First claim

What is claimed is:

1 . A system, comprising:
a NO x sensor; and a controller configured to:
interpret a value of a first parameter indicative of an amount of NO x measured by the NO x sensor;
interpret a value of a second parameter for a NO x value from a look-up table;
determine a correction factor based on the value of the first parameter and the value of the second parameter; and
generate a dosing command based, at least in part, on the determined correction factor.

2 . The system of claim 1 , wherein the NO x value from the look-up table is based on one or more operating conditions of an engine.

3 . The system of claim 2 , wherein the one or more operating conditions of the engine comprise an engine speed, an engine torque, or a fueling condition.

4 . The system of claim 1 , wherein the controller is further configured to:
store the determined correction factor in a data storage.

5 . The system of claim 1 , wherein the controller is further configured to:
update the NO x value of the look-up table based on the determined correction factor.

6 . The system of claim 1 , wherein the controller is further configured to:
determine the determined correction factor is greater than or equal to a threshold value; and store the determined correction factor in a data storage responsive to determining that the correction factor is greater than or equal to the threshold value.

7 . The system of claim 1 , wherein the controller is further configured to:
generate a correction factor curve based, at least in part, on the determined correction factor.

8 . The system of claim 1 , wherein the controller is further configured to:
determine a no-dosing period is occurring; wherein the interpreting of the value of the first parameter indicative of the amount of NO x measured by the NO x sensor is responsive to determining that the no-dosing period is occurring.

9 . The system of claim 1 , further comprising:
a dosing module; wherein the controller is further configured to control the dosing module based on the generated dosing command.

10 . A system, comprising:
a NO x sensor; and a controller configured to:
interpret a plurality of values of a first parameter indicative of amounts of NO x measured by the NO x sensor for a plurality of operating conditions;
interpret a plurality of values of a second parameter for NO x values from a look-up table for the plurality of operating conditions;
determine plurality of correction factors based on the plurality of values of the first parameter and the plurality of values of the second parameter; and
generate a dosing command based, at least in part, on a correction factor of the determined plurality of correction factors.

11 . The system of claim 10 , wherein the plurality of operating conditions comprise one or more of a plurality of engine speeds, a plurality of engine torques, or a plurality of fueling conditions.

12 . The system of claim 10 , wherein the controller is further configured to:
store the determined plurality of correction factors in a data storage.

13 . The system of claim 10 , wherein the controller is further configured to:
update a plurality of NO x values of the look-up table based on the determined plurality of correction factors.

14 . The system of claim 10 , wherein the controller is further configured to:
determine a correction factor of the determined plurality of correction factors is greater than or equal to a threshold value; and store the correction factor in a data storage responsive to determining that the correction factor is greater than or equal to the threshold value.

15 . The system of claim 10 , wherein the controller is further configured to:
generate a correction factor curve based, at least in part, on the determined plurality of correction factors.

16 . The system of claim 10 , wherein the controller is further configured to:
determine whether a no-dosing period is occurring; wherein the interpreting of the plurality of values of the first parameter indicative of amounts of NO x measured by the NO x sensor for the plurality of operating conditions is responsive to determining that the no-dosing period is occurring.

17 . The system of claim 10 , wherein a correction factor of the determined plurality of correction factors is associated with a range for an operating condition of the plurality of operating conditions.

18 . The system of claim 17 , wherein generating the dosing command comprises modifying a NO x value from the look-up table by the correction factor associated with the range for the operating condition when an engine is operating within the range of the operating condition.

19 . The system of claim 10 , further comprising:
a dosing module; wherein the controller is further configured to control the dosing module based on the generated dosing command.

20 . A method comprising:
determining a no-dosing period for an aftertreatment system; interpreting a plurality of values of a first parameter indicative of amounts of NO x measured by the NO x sensor for a plurality of operating conditions responsive to determining the no-dosing period; interpreting a plurality of values of a second parameter for NO x values from a look-up table for the plurality of operating conditions of an engine; determining a plurality of correction factors based on the plurality of values of the first parameter and the plurality of values of the second parameter; generating a correction factor curve based, at least in part, on the determined plurality of correction factors; generating a dosing command based on a value from the correction factor curve; and transmitting the generated dosing command to a dosing module of the aftertreatment system to control dosing of reductant from the dosing module.

21 . The method of claim 20 , wherein a correction factor of the determined plurality of correction factors is associated with a range for an operating condition of the plurality of operating conditions.

22 . The system of claim 20 , wherein the plurality of operating conditions comprise one or more of a plurality of engine speeds, a plurality of engine torques, or a plurality of fueling conditions.

Assignees

• Cummins Emission Solutions Inc

Inventors

• Ponnathpur Chetan
• Sonawane Sarang S

Classifications

• B01D53/9495

  Controlling the catalytic process · CPC title

• B01D2251/206

  Ammonium compounds · CPC title

• B01D53/9418

  for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas · CPC title

• F01N2900/1402

  Exhaust gas composition · CPC title

• F01N3/208 Primary

  Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent · CPC title