Particulate trap temperature sensor swap detection

• US 20090107114A1
• Filed: 10/31/2007
• Published: 04/30/2009
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Ammineni, Chandini M., Zich, Andrew J.
• Granted Patent: US 7,891,177 B2
• Time in Patent Office: Days
• US Class Current: 60/277
• CPC Class Codes: F01N 11/002 the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F01N 2550/00 Monitoring or diagnosing the deterioration of exhaust systems
• CPC Class Codes: F02D 41/0235 in relation with the state of the exhaust gas treating apparatus control of exhaust gas treating apparatus per se F01N
• CPC Class Codes: F02D 41/1441 Plural sensors
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices

Abstract

An exhaust after-treatment system is disclosed. The system has a particulate trap disposed to remove particulate matter from an exhaust flow of an engine, an upstream temperature sensor disposed to measure a temperature of the exhaust flow upstream of the particulate trap, and a downstream temperature sensor disposed to measure a temperature of the exhaust flow downstream of the particulate trap. The system also has a controller in communication to receive from the upstream and downstream temperature sensors indications of the upstream and downstream temperatures. The controller is configured to compare the upstream and downstream temperatures, determine if the upstream and downstream temperature sensors are improperly swapped based on the comparison, and take a precaution if it is determined that the upstream and downstream temperature sensors are improperly swapped.

Claims

1. An exhaust after-treatment system, comprising:

a particulate trap disposed to remove particulate matter from an exhaust flow of an engine;

an upstream temperature sensor disposed to measure a temperature of the exhaust flow upstream of the particulate trap;

a downstream temperature sensor disposed to measure a temperature of the exhaust flow downstream of the particulate trap; and

a controller in communication to receive from the upstream and downstream temperature sensors indications of the upstream and downstream temperatures, the controller being configured to;

compare the upstream and downstream temperatures;

determine if the upstream and downstream temperature sensors are improperly swapped based on the comparison; and

take a precaution if it is determined that the upstream and downstream temperature sensors are improperly swapped.

2. The system of claim 1, wherein taking a precaution includes at least one of logging a fault indicating that the upstream and downstream temperature sensors are improperly swapped, terminating a current particulate trap regeneration event, and precluding future particulate trap regeneration events.

3. The system of claim 1, further including a regeneration device disposed with the particulate trap and configured to reduce buildup of particulate matter within the particulate trap, wherein:

taking a precaution includes swapping the indications of the upstream and downstream temperatures, and

the controller is in communication with and configured to control the regeneration device based on the swapped upstream and downstream temperature indications.

4. The system of claim 1, wherein the controller is further configured to compare the upstream and downstream temperatures at the onset of or upon the conclusion of a particulate trap regeneration event.

5. The system of claim 4, wherein the controller is further configured to wait until either or both of the upstream and downstream temperatures have risen or fallen by a specified amount, or to wait a specified amount of time since the onset of or the completion of the particulate trap regeneration event, before comparing the upstream and downstream temperatures.

6. The system of claim 5, wherein it is determined that the upstream and downstream temperature sensors are improperly swapped if the difference between the downstream temperature and the upstream temperature is above or below a threshold.

7. A method, comprising:

disposing a particulate trap to remove particulate matter from an exhaust flow of an engine;

receiving from an upstream temperature sensor an indication of a temperature of the exhaust flow upstream of the particulate trap;

receiving from a downstream temperature sensor an indication of a temperature of the exhaust flow downstream of the particulate trap;

comparing the upstream and downstream temperatures;

determining if the upstream and downstream temperature sensors are improperly swapped based on the comparison; and

taking a precaution if it is determined that the upstream and downstream temperature sensors are improperly swapped.

8. The method of claim 7, wherein taking a precaution includes at least one of logging a fault indicating that the upstream and downstream temperature sensors are improperly swapped, terminating a current particulate trap regeneration event, and precluding future particulate trap regeneration events.

9. The method of claim 7, wherein taking a precaution includes:

swapping the indications of the upstream and downstream temperatures, and

controlling regeneration of the particulate trap based on the swapped upstream and downstream temperature indications.

10. The method of claim 7, wherein the comparing is performed at the onset of a particulate trap regeneration event.

11. The method of claim 10, further including waiting until either or both of the upstream and downstream temperatures have risen by a specified amount, or waiting a specified amount of time since the onset of the particulate trap regeneration event, before comparing the upstream and downstream temperatures.

12. The method of claim 11, wherein it is determined that the upstream and downstream temperature sensors are improperly swapped if the difference between the downstream temperature and the upstream temperature is above a threshold.

13. The method of claim 7, wherein the comparing is performed upon the conclusion of a particulate trap regeneration event.

14. The method of claim 13, further including waiting until either or both of the upstream and downstream temperatures have fallen by a specified amount, or waiting a specified amount of time since the completion of the particulate trap regeneration event, before comparing the upstream and downstream temperatures.

15. The method of claim 14, wherein it is determined that the upstream and downstream temperature sensors are improperly swapped if the difference between the downstream temperature and the upstream temperature is below a threshold.

16. A machine, comprising:

a combustion engine configured to power operations of the machine; and

an exhaust after-treatment system, comprising;

a particulate trap disposed to remove particulate matter from an exhaust flow of an engine;

an upstream temperature sensor disposed to measure a temperature of the exhaust flow upstream of the particulate trap;

a downstream temperature sensor disposed to measure a temperature of the exhaust flow downstream of the particulate trap; and

a controller in communication to receive from the upstream and downstream temperature sensors indications of the upstream and downstream temperatures, the controller being configured to;

compare the upstream and downstream temperatures;

determine if the upstream and downstream temperature sensors are improperly swapped based on the comparison; and

take a precaution if it is determined that the upstream and downstream temperature sensors are improperly swapped.

17. The machine of claim 16, wherein taking a precaution includes at least one of logging a fault indicating that the upstream and downstream temperature sensors are improperly swapped, terminating a current particulate trap regeneration event, and precluding future particulate trap regeneration events.

18. The machine of claim 16, further including a regeneration device disposed with the particulate trap and configured to reduce buildup of particulate matter within the particulate trap, wherein:

taking a precaution includes swapping the indications of the upstream and downstream temperatures, and

the controller is in communication with and configured to control the regeneration device based on the swapped upstream and downstream temperature indications.

19. The machine of claim 16, wherein the controller is further configured to compare the upstream and downstream temperatures at the onset of or upon the conclusion of a particulate trap regeneration event.

20. The machine of claim 19, wherein:

the controller is further configured to wait until either or both of the upstream and downstream temperatures have risen or fallen by a specified amount prior to comparing the upstream and downstream temperatures, and

it is determined that the upstream and downstream temperature sensors are improperly swapped if the difference between the measured downstream temperature and the measured upstream temperature is above or below a threshold.