System and method for performing a particulate sensor diagnostic

• US 20070125349A1
• Filed: 12/06/2005
• Published: 06/07/2007
• Est. Priority Date: 12/06/2005
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: van Nieuwstadt, Michiel, Zanini-Fisher, Margherita
• Granted Patent: US 7,278,304 B2
• Time in Patent Office: Days
• US Class Current: 123/679
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 2550/00 Monitoring or diagnosing the deterioration of exhaust systems
• CPC Class Codes: F01N 2560/05 the means being a particulate sensor
• CPC Class Codes: F02D 41/0055 Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/1459 the characteristics being a hydrocarbon content or concentration
• CPC Class Codes: F02D 41/1466 the characteristics being a soot concentration or content
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An apparatus comprising an internal combustion engine, an exhaust system in communication with the engine, a particulate sensor associated with the exhaust system, and a controller in electrical communication with the particulate sensor, wherein the controller is configured to determine a change in a rate of exhaust flow in the exhaust system, to compare the change in the rate of exhaust flow to a preselected threshold rate of change; and if the change in the rate of exhaust flow has a preselected relationship to the preselected threshold rate of change, then to determine a degradation of the sensor.

Claims

1. An apparatus, comprising:

an internal combustion engine;

an exhaust system in communication with the engine;

a particulate sensor associated with the exhaust system; and

a controller in electrical communication with the particulate sensor, wherein the controller is configured to determine a change in a rate of exhaust flow in the exhaust system;

to compare the change in the rate of exhaust flow to a preselected threshold rate of change; and

if the change in the rate of exhaust flow has a preselected relationship to the preselected threshold rate of change, then to determine a degradation of the sensor.

2. The apparatus of claim 1, wherein the controller is configured to determine the degradation of the sensor by determining if an output of the particulate sensor has a preselected relationship to a predetermined sensor output threshold.

3. The apparatus of claim 2, wherein the controller is configured to determine a measure of particulate accumulation on an interior surface of the exhaust system upstream of the particulate sensor, and wherein the predetermined sensor output threshold value is associated with the measure of particulate matter accumulation.

4. The apparatus of claim 3, wherein the controller comprises memory comprising a plurality of predetermined sensor output threshold values stored thereon, each predetermined sensor output threshold value being associated with a corresponding measure of particulate matter accumulation.

5. The apparatus of claim 1, wherein the sensor comprises an image charge sensor.

6. The apparatus of claim 1, further comprising a particulate filter disposed along the exhaust system, wherein the sensor is disposed upstream of the particulate filter.

7. The apparatus of claim 1, further comprising a particulate filter disposed along the exhaust system, wherein the sensor is disposed downstream of the particulate filter.

8. The apparatus of claim 1, wherein the particulate sensor is a first particulate sensor, further comprising a second particulate sensor disposed along the exhaust system upstream of the particulate filter.

9. An apparatus, comprising:

an internal combustion engine;

an exhaust system in communication with the engine;

an image charge sensor at least partially exposed to exhaust gases in the exhaust system; and

a controller in electrical communication with the image charge sensor to determine a degradation of the sensor in response to an engine operating condition.

10. The apparatus of claim 9, wherein the controller is configured to determine the degradation of the sensor by comparing an output received from the sensor to a predetermined sensor output threshold value and determining whether the output received from the sensor has a predetermined relationship to the predetermined sensor output threshold value.

11. The apparatus of claim 10, wherein the controller is configured to determine a measure of particulate accumulation on an interior surface of the exhaust system upstream of the particulate sensor, and wherein the predetermined sensor output threshold value is associated with the measure of particulate matter accumulation.

12. The apparatus of claim 11, wherein the controller comprises memory comprising a plurality of predetermined sensor output threshold values stored thereon, each predetermined sensor output threshold value being associated with a corresponding measure of particulate matter accumulation.

13. The apparatus of claim 9, wherein the operating condition comprises an increase in a rate of exhaust flow.

14. The apparatus of claim 13, wherein the operating condition comprises an increase in the rate of exhaust flow being equal to or above a predetermined threshold exhaust flow rate increase.