TEMPERATURE ESTIMATION SYSTEMS AND METHODS

• US 20120047875A1
• Filed: 09/23/2010
• Published: 03/01/2012
• Est. Priority Date: 08/30/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Hamama, Wajdi B., Genslak, Robert J., Lockwood, Alan Root, Goodall, James A., El-Jaroudi, Mather
• Granted Patent: US 8,857,157 B2
• Time in Patent Office: Days
• US Class Current: 60/274
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector
• CPC Class Codes: F01N 2900/0418 using integration or an accumulated value within an elapsed period
• CPC Class Codes: F01N 2900/0601 being estimated
• CPC Class Codes: F01N 2900/1602 Temperature of exhaust gas apparatus
• CPC Class Codes: F01N 9/00 Electrical control of exhaust gas treating apparatus monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00
• CPC Class Codes: F02B 37/007 with exhaust-driven pumps arranged in parallel , e.g. at least one pump supplying alternatively
• CPC Class Codes: F02D 2200/0804 Estimation of the temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/1447 with determination means using an estimation
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system for a vehicle includes a steady-state (SS) temperature module and a mass temperature module. The SS temperature module generates a SS temperature of a downstream-most catalyst of an exhaust system at a predetermined location between upstream and downstream faces of the downstream-most catalyst. The predetermined location is a predetermined distance upstream from the downstream face. The mass temperature module generates an instantaneous temperature of the downstream-most catalyst at the predetermined location as a function of the SS temperature.

Claims

1. A system for a vehicle, comprising:

a steady-state (SS) temperature module that generates a SS temperature of a downstream-most catalyst of an exhaust system at a predetermined location between upstream and downstream faces of the downstream-most catalyst,

wherein the predetermined location is a predetermined distance upstream from the downstream face; and

a mass temperature module that generates an instantaneous temperature of the downstream-most catalyst at the predetermined location as a function of the SS temperature.

2. The system of claim 1 further comprising:

a tip-in module that indicates when a tip-in event occurs; and

a tip-out module that indicates when a tip-out event occurs,

wherein the SS temperature module selectively maintains the SS temperature after one of the tip-in event and the tip-out event begins.

3. The system of claim 2 further comprising an accumulation module that determines an accumulated mass of exhaust gas that has flowed into the downstream-most catalyst since the one of the tip-in event and the tip-out event began,

wherein the SS temperature module maintains the SS temperature until the accumulated mass is greater than a predetermined mass.

4. The system of claim 3 wherein, when the accumulated mass is greater than the predetermined mass, the SS temperature module generates the SS temperature as a function of a temperature of gas input to the downstream-most catalyst, an ambient temperature, and a SS coefficient determined based on an exhaust flow rate into the downstream-most catalyst.

5. The system of claim 2 further comprising a coefficient determination module that determines a mass coefficient as a function of an exhaust flow rate into the downstream-most catalyst,

wherein the mass temperature module generates the instantaneous temperature as a function of the SS temperature, a previous value of the instantaneous temperature, and the mass coefficient, and

wherein the coefficient determination module selectively maintains the mass coefficient after the one of the tip-in event and the tip-out event begins.

6. The system of claim 5 wherein the coefficient determination module maintains the mass coefficient for a predetermined period after the one of the tip-in event and the tip-out event begins.

7. The system of claim 6 further comprising an accumulation module that determines an accumulated mass of exhaust gas that has flowed into the downstream-most catalyst since the one of the tip-in event and the tip-out event began,

wherein, after the predetermined period, the coefficient determination module (I) determines the mass coefficient as a function of the exhaust flow rate into the downstream-most catalyst, (II) adjusts the mass coefficient based on a first predetermined adjustment before the accumulated mass is greater than a predetermined mass, and (III) adjusts the mass coefficient based on a second predetermined adjustment after the accumulated mass is greater than the predetermined mass.

8. The system of claim 5 further comprising a high load detection module that indicates whether a high load condition is present based on an engine load parameter,

wherein the coefficient determination maintains the mass coefficient after the one of the tip-in event and the tip-out event begins when the high load condition was present when the one of the tip-in event and the tip-out event began.

9. The system of claim 1 further comprising a fuel cut off (FCO) module that indicates when fuel to an engine of the vehicle is cut off,

wherein the SS temperature module selectively maintains the SS temperature after the fuel to the engine is cut off.

10. The system of claim 9 wherein the SS temperature module (I) maintains the SS temperature for a predetermined period after the fuel to the engine is cut off, (II) after the predetermined period, generates the SS temperature as a function of a temperature of gas input to the downstream-most catalyst, an ambient temperature, and a SS coefficient determined based on an exhaust flow rate into the downstream-most catalyst, and (III) adds a predetermined offset to the SS temperature after the predetermined period.

11. A method for a vehicle, comprising:

generating a steady-state (SS) temperature of a downstream-most catalyst of an exhaust system at a predetermined location between upstream and downstream faces of the downstream-most catalyst,

wherein the predetermined location is a predetermined distance upstream from the downstream face; and

generating an instantaneous temperature of the downstream-most catalyst at the predetermined location as a function of the SS temperature.

12. The method of claim 11 further comprising:

indicating when a tip-in event occurs;

indicating when a tip-out event occurs; and

selectively maintaining the SS temperature after one of the tip-in event and the tip-out event begins.

13. The method of claim 12 further comprising:

determining an accumulated mass of exhaust gas that has flowed into the downstream-most catalyst since the one of the tip-in event and the tip-out event began; and

maintaining the SS temperature until the accumulated mass is greater than a predetermined mass.

14. The method of claim 13 further comprising, when the accumulated mass is greater than the predetermined mass, generating the SS temperature as a function of a temperature of gas input to the downstream-most catalyst, an ambient temperature, and a SS coefficient determined based on an exhaust flow rate into the downstream-most catalyst.

15. The method of claim 12 further comprising:

determining a mass coefficient as a function of an exhaust flow rate into the downstream-most catalyst;

generating the instantaneous temperature as a function of the SS temperature, a previous value of the instantaneous temperature, and the mass coefficient; and

selectively maintaining the mass coefficient after the one of the tip-in event and the tip-out event begins.

16. The method of claim 15 further comprising maintaining the mass coefficient for a predetermined period after the one of the tip-in event and the tip-out event begins.

17. The method of claim 16 further comprising:

determining an accumulated mass of exhaust gas that has flowed into the downstream-most catalyst since the one of the tip-in event and the tip-out event began; and

,

after the predetermined period;

determining the mass coefficient as a function of the exhaust flow rate into the downstream-most catalyst;

adjusting the mass coefficient based on a first predetermined adjustment before the accumulated mass is greater than a predetermined mass; and

adjusting the mass coefficient based on a second predetermined adjustment after the accumulated mass is greater than the predetermined mass.

18. The method of claim 15 further comprising:

indicating whether a high load condition is present based on an engine load parameter; and

maintaining the mass coefficient after the one of the tip-in event and the tip-out event begins when the high load condition was present when the one of the tip-in event and the tip-out event began.

19. The method of claim 11 further comprising:

indicating when fuel to an engine of the vehicle is cut off; and

selectively maintaining the SS temperature after the fuel to the engine is cut off.

20. The method of claim 19 further comprising:

maintaining the SS temperature for a predetermined period after the fuel to the engine is cut off;

after the predetermined period, generating the SS temperature as a function of a temperature of gas input to the downstream-most catalyst, an ambient temperature, and a SS coefficient determined based on an exhaust flow rate into the downstream-most catalyst; and

adding a predetermined offset to the SS temperature after the predetermined period.