Method and apparatus for determining temperature in a gas feedstream

• US 8,152,369 B2
• Filed: 10/22/2010
• Issued: 04/10/2012
• Est. Priority Date: 09/11/2007
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Ma, Qi, Verdejo, Julian R., Kalweit, Nicholas John
• Primary Examiner(s): VERBITSKY, GAIL KAPLAN
• Application Number:
  US12/909,926
• Publication Number:
  US 20110038394A1
• Time in Patent Office: 536 Days
• Field of Search: 374/29, 374/30, 374 43- 45, 374 39- 40, 374/137, 374141-144, 374/147, 374/163, 374/183, 374/166, 374/167, 374/4, 374/5, 374/57, 374/27, 374/208, 374/185, 374/148, 374/135, 602/77, 602/72, 602/38, 73/232.5, 73/232.6, 73/250.3, 73/250.1, 73/310.5, 731/146.9, 731/147.1, 731/147.2, 731/147.3, 731/144.2, 731/143.4, 738/610.4, 732/041.1, 204/401, 123/697, 123/679, 123/676, 702/183, 703/2, 701/108
• US Class Current: 374/147
• CPC Class Codes: F02D 2041/1416 Observer
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/1447 with determination means using an estimation
• CPC Class Codes: F02D 41/1494 Control of sensor heater
• CPC Class Codes: G01K 13/02 for measuring temperature of moving fluids or granular materials capable of flow
• CPC Class Codes: G01K 2205/04 for measuring exhaust gas temperature

Abstract

An internal combustion engine includes an exhaust gas feedstream flowing past a gas sensing device disposed therein. The gas sensor includes an integrated electrical heating element which provides a resistance indicative of its temperature. An unknown input observer is used to determine the exhaust gas feedstream temperature based on the heating element temperature.

Claims

1. Method for measuring a gas feedstream temperature, comprising:

providing a gas sensing device including an integrated heating element and surrounded by a lower shield filled with the gas, the sensing device disposed within the gas feedstream;

measuring electrical resistance of the integrated heating element;

determining temperature of the integrated heating element based upon the measured electrical resistance;

executing an unknown input observer model to estimate a gas temperature within the lower shield surrounding the sensing device based upon the temperature of the integrated heating element; and

,

determining the gas feedstream temperature based upon the estimated gas temperature within the lower shield surrounding the sensing device.

2. The method of claim 1, wherein the unknown input observer model comprises a linear model.

3. The method of claim 1, wherein the gas feedstream comprises post-combustion process exhaust gases.

4. The method of claim 3, wherein the post-combustion process exhaust gases comprise exhaust gases from an internal combustion engine.

5. Control system for monitoring an exhaust gas feedstream, comprising:

a sensing device having an integrated heating element and surrounded by a lower shield filled with the gas;

a control module monitoring an electrical resistance of the integrated heating element, determining a temperature of the integrated heating element based upon the electrical resistance, using an unknown input observer model to estimate a gas temperature within the lower shield surrounding the sensing device based upon the temperature of the integrated heating element, and determining a temperature of the gas feedstream based upon the gas temperature within the lower shield surrounding the sensing device.

6. The control system of claim 5, wherein the unknown input observer model comprises a linear model.

7. The control system of claim 5, wherein the control module determining a temperature of the gas feedstream based upon the gas temperature within the lower shield surrounding the sensing device comprises the control module determining temperature of the gas feedstream at a predetermined location based upon the gas temperature within the lower shield surrounding the sensing device.

8. The control system of claim 5, wherein the sensing device having an integrated heating element comprises a planar-type exhaust gas sensing device.

9. The control system of claim 5, wherein the sensing device is configured to monitor a partial pressure of oxygen.

10. The control system of claim 5, wherein the sensing device is configured to monitor a gas constituent.

11. The control system of claim 5, wherein the sensing device is configured to monitor nitrides of oxygen.

12. Control system for monitoring an exhaust gas feedstream within an exhaust gas aftertreatment system, comprising:

an integrated heating element of a sensing device adapted to monitor the exhaust gas feedstream the sensing device is surrounded by a lower shield filled with the gas;

a control module monitoring electrical resistance of the integrated heating element of the sensing device, determining a temperature of the integrated heating element based upon the electrical resistance, estimating a gas temperature within the lower shield surrounding the sensing device based upon the temperature of the integrated heating element using an unknown input observer model, and determining a temperature of the exhaust gas feedstream based upon the estimated gas temperature within the lower shield surrounding the sensing device.

13. The control system of claim 12, wherein the sensing device having an integrated heating element comprises a planar-type exhaust gas sensing device.

14. The control system of claim 13, wherein the sensing device monitors a partial pressure of oxygen.

15. The control system of claim 13, wherein the sensing device monitors nitrides of oxygen.