NOx model

Patent metadata

Field	Value
Publication number	US-9921131-B2
Application number	US-201313870482-A
Country	US
Kind code	B2
Filing date	Apr 25, 2013
Priority date	Apr 25, 2013
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Methods are provided for estimating the NO x content of exhaust gas produced by an internal combustion engine. The method includes determining one or more operating parameters. The method further includes applying the determined operating parameter(s) to a global NO x model. The global NO x model may be derived using a plurality of steady state data points relating to local NO x emission models. The steady state data points may be derived using a plurality of set and variable operating parameters. The global NO x model allows for prediction of the engine-out NO x content of exhaust gas in real time and without a NO x sensor, even if engine operating parameters change.

First claim

The invention claimed is:

1. A method for controlling an aftertreatment device based on estimating an engine-out NO x content of exhaust gas produced by an internal combustion engine, without the need to determine cylinder pressure, the method comprising:
determining an engine speed and sending a signal indicative of the determined engine speed;
determining an engine load and sending a signal indicative of the determined engine load;
determining an intake oxygen level and sending a signal indicative of the determined intake oxygen level;
determining a fuel pressure and sending a signal indicative of the determined fuel pressure;
determining a fuel quantity and sending a signal indicative of the determined fuel quantity; and
sending each of the signals indicative of the determined engine speed, engine load, intake oxygen level, fuel pressure, and fuel quantity to a control unit which is programmed to receive and process each of the signals indicative of determined engine speed, engine load, intake oxygen level, fuel pressure, and fuel quantity using a NO x model which utilizes a linear relationship between the intake oxygen level and engine-out NOx for the signal indicative of predetermined engine speed, and which utilizes a linear relationship between the intake oxygen level and engine-out NOx for the signal indicative of engine load, and which utilizes a linear relationship between the intake oxygen level and engine-out NOx for the signal indicative of intake oxygen level, and which utilizes a linear relationship between the intake oxygen level and engine-out NOx for the signal indicative of fuel pressure, and which utilizes a linear relationship between the intake oxygen level and engine-out NOx for the signal indicative of fuel quantity to arrive at an estimate of the engine-out NO x content; and
controlling an aspect of the aftertreatment device based on the estimated engine-out NOx content.

2. The method of claim 1 , wherein the NO x model applied by the control unit is based at least in part on a map emission response surface model that is a function of engine speed and engine torque.

3. The method of claim 1 , wherein the NO x model applied by the control unit is based on a plurality of local NO x models that are generated using one or more set operating parameters and one or more variable operating parameters.

4. The method of claim 3 , wherein the one or more variable operating parameters include at least one of the following: a local intake oxygen level; a local fuel pressure; and a local fuel quantity.

5. The method of claim 4 , wherein the one or more set operating parameters include a constant engine speed and/or a constant engine torque.

6. The method of claim 5 , wherein the plurality of local NO x models are derived using the design of experiments method.

Assignees

• Int Eng Ip Co Llc

Inventors

• Singh Navtej

Classifications

• F02D2200/602

  Pedal position · CPC title

• F02D2200/0602

  Fuel pressure · CPC title

• F02D41/2416

  Interpolation techniques · CPC title

• F02D41/144

  Sensor in intake manifold · CPC title

• F02D2200/0614

  Actual fuel mass or fuel injection amount · CPC title