Exhaust system for a motor vehicle

Patent metadata

Field	Value
Publication number	US-10132218-B2
Application number	US-201415304754-A
Country	US
Kind code	B2
Filing date	Apr 16, 2014
Priority date	Apr 16, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

The present disclosure relates to engines for a motor vehicle and some embodiments include a method for operating an exhaust train of a motor vehicle engine including: measuring a particle concentration downstream of a particle filter at a first operating point; determining the filter efficiency at the first operating point; changing operation of the engine to a second operating point to increase the particle emissions; measuring the particle concentration downstream of the filter at the second operating point; determining the filter efficiency at the second operating point; determining a difference between the efficiency levels; detecting an offset error, if the difference exceeds a defined threshold; and identifying a particle sensor as defective if an offset error is detected, rather than identifying the particle filter as defective.

First claim

The invention claimed is:

1. A method for operating an exhaust train of a motor vehicle engine, the method comprising:
measuring a particle concentration with a soot sensor disposed in an exhaust gas downstream of a particle filter at a first operating point;
using an electronic control unit (ECU) programmed to determine a first filter efficiency level at the first operating point based at least in part on the measured particle concentration and a modeled particle concentration upstream of the particle filter based on the first operating point;
using the ECU programmed to change operation of the engine to a second operating point at which the particle emissions upstream of the particle filter rise strongly;
measuring the particle concentration with the soot sensor in the exhaust gas downstream of the particle filter at the second operating point;
using the ECU programmed to determine a second filter efficiency level at the second operating point based at least in part on the measured particle concentration and a modeled particle concentration upstream of the particle filter based on the second operating point;
using the ECU programmed to determine an absolute difference between the first and second filter efficiency levels;
using the ECU programmed to detect an offset error, if the absolute difference between the filter efficiency levels exceeds a defined threshold; and
using the ECU programmed to identify a particle sensor as defective if an offset error is detected, rather than identifying the particle filter as defective.

2. The method as claimed in claim 1 , wherein the first operating point is one with low particle emissions.

3. The method as claimed in claim 1 , further comprising using the ECU programmed to stabilize the operation of the motor during a stabilization phase before measuring the particle concentration at each of the first and second operating points.

4. The method as claimed in claim 1 , further comprising using the ECU programmed to determine whether a positive or negative offset is present depending on the sign of the difference between the filter efficiency levels.

5. The method as claimed in claim 1 , further comprising using the ECU programmed to determine the offset of the particle sensor used to measure the particle concentration.

6. An exhaust system for an engine of a motor vehicle, the system comprising:
an exhaust train delivering an exhaust gas from the engine;
a particle filter arranged in the exhaust train;
a sensor measuring a particle concentration in the exhaust gas downstream of the particle filter; and
a controller operable to:
determine a filter efficiency level at a first operating point of the engine based on a measured particle concentration and a modeled particle concentration upstream of the particle filter at the first operating point;
change the operating point of the engine to a second operating point at which the particle emissions upstream of the particle filter rise strongly;
determine a second filter efficiency level at the second operating point based on a second measured particle concentration and a modeled particle concentration upstream of the particle filter at the second operating point;
determine an absolute difference between the filter efficiency levels and identifies an offset error, if the absolute difference between the filter efficiency levels exceeds a defined threshold; and
identify a particle sensor as defective if an offset error is detected, rather than identifying the particle filter as defective.

7. The exhaust system as claimed in claim 6 , wherein the first operating point is one with low particle emissions.

8. The exhaust system as claimed in claim 6 , wherein the controller provides a stabilization phase before measuring the particle concentration at each of the first and second operating points.

9. The exhaust system as claimed in claim 6 , further comprising determining whether a positive or negative offset is present depending on the sign of the difference between the filter efficiency levels.

10. The exhaust system as claimed in claim 6 , wherein the controller determines the offset of a particle sensor used to measure the particle concentration.

Assignees

• Continental Automotive Gmbh

Inventors

• Rodatz Paul
• Nienhoff Michael
• Arlt Tino
• Schoen Thomas

Classifications

• Y02T10/47

  Cross-Sectional Technologies · mapped topic

• Y02T10/20

  Cross-Sectional Technologies · mapped topic

• F01N2560/05

  the means being a particulate sensor · CPC title

• F01N3/021 Primary

  by means of filters · CPC title

• F01N11/00 Primary

  Monitoring or diagnostic devices for exhaust-gas treatment apparatus · CPC title