Compensating for random catalyst behavior

• US 8,346,458 B2
• Filed: 03/01/2010
• Issued: 01/01/2013
• Est. Priority Date: 10/01/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Midlam-Mohler, Shawn W., Rajagopalan, Sai S. V., Dudek, Kenneth P., Yurkovich, Stephen, Guezennec, Yann G.
• Primary Examiner(s): Kwon, John
• Assistant Examiner(s): HOANG, JOHNNY H
• Application Number:
  US12/714,854
• Publication Number:
  US 20110082635A1
• Time in Patent Office: 1,037 Days
• Field of Search: 701/104, 701/106, 701/109, 701/114, 701/115, 123/1.A, 123/27.GE, 123/525, 123/527, 123/672, 123/698, 123/699, 123/703, 60276-278, 602/99, 602/85, 731/143.1, 731/145.2, 731/145.3, 731/147.2, 731/147.3, 731/146.9, 731/147.1, 731/147.5
• US Class Current: 701/104
• CPC Class Codes: F02D 2041/1409 using at least a proportional, integral or derivative controller
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 41/1441 Plural sensors
• CPC Class Codes: F02D 41/1458 with determination means using an estimation
• CPC Class Codes: F02D 41/2432 Methods of calibration
• CPC Class Codes: F02D 41/2474 Characteristics of sensors

Abstract

A method for calibrating an engine control module includes sampling a first signal from a first oxygen sensor located upstream from a catalyst. The first signal indicates an oxygen content of exhaust gas produced by an engine. The method further includes predicting a response of a second oxygen sensor located downstream from the catalyst using a model of the catalyst and the first signal and sampling a second signal from the second oxygen sensor. The method further includes determining a component of the second signal based on a difference between samples of the second signal and the predicted response. The component is due to gases other than oxygen. Additionally, the method includes calibrating the engine control module based on the component of the second signal. The engine control module controls an amount of fuel injected into the engine.

Claims

1. A method for calibrating an engine control module, comprising:

sampling a first signal from a first oxygen sensor located upstream from a catalyst, wherein the first signal indicates an oxygen content of exhaust gas produced by an engine;

predicting a response of a second oxygen sensor located downstream from the catalyst using a model of the catalyst and the first signal;

sampling a second signal from the second oxygen sensor;

determining a component of the second signal based on a difference between samples of the second signal and the predicted response, wherein the component is due to gases other than oxygen; and

calibrating the engine control module based on the component of the second signal, wherein the engine control module controls an amount of fuel injected into the engine.

2. The method of claim 1, wherein the gases other than oxygen include hydrogen gas.

3. The method of claim 1, wherein the gases other than oxygen include unburned hydrocarbons.

4. The method of claim 2, wherein the hydrogen gas is released from the catalyst.

5. The method of claim 1, further comprising calibrating a control architecture of the engine control module, wherein the control architecture includes at least one of proportional-integral-derivative (PID) control, gain-scheduled PID control, H-infinity control, sliding mode control (SMC), and fuzzy logic control.

6. The method of claim 1, further comprising:

determining a rate of decay of the difference; and

calibrating the engine control module based on the rate of decay.

7. The method of claim 1, wherein the engine control module controls the amount of fuel based on a difference between a reference signal and signals received from the second oxygen sensor during operation of the engine.

8. The method of claim 7, wherein the reference signal indicates a desired composition of the exhaust gas at the second oxygen sensor.

9. The method of claim 8, wherein the reference signal indicates a stoichiometric ratio.

10. The method of claim 1, further comprising:

determining a plurality of the components during a period of operation of the engine; and

calibrating the engine control module based on the plurality of the components.

11. The method of claim 10, wherein each of the plurality of the components is based on a rate of decay of the difference.

12. The method of claim 11, further comprising calibrating the engine control module using a model based calibration that includes the model of the catalyst.

13. The method of claim 1, further comprising predicting the response based on at least one of a temperature of the exhaust gas and a flow rate of the exhaust gas.

14. The method of claim 1, wherein the model predicts the response based on the first signal and at least one of a temperature of the exhaust gas and a flow rate of the exhaust gas.

15. A system for calibrating an engine control module, comprising:

a catalyst simulation module that;

samples a first signal from a first oxygen sensor located upstream from a catalyst, wherein the first signal indicates an oxygen content of exhaust gas produced by an engine; and

predicts a response of a second oxygen sensor located downstream from the catalyst using a model of the catalyst and the first signal;

a component determination module that samples a second signal from the second oxygen sensor and that determines a component of the second signal based on a difference between samples of the second signal and the predicted response, wherein the component is due to gases other than oxygen; and

a calibration module that calibrates the engine control module based on the component of the second signal, wherein the engine control module controls an amount of fuel injected into the engine.

16. The system of claim 15, wherein the gases other than oxygen include hydrogen gas.

17. The system of claim 16, wherein the hydrogen gas is released from the catalyst.

18. The system of claim 15, wherein the calibration module calibrates a control architecture of the engine control module, and wherein the control architecture includes at least one of proportional-integral-derivative (PID) control, gain-scheduled PID control, H-infinity control, sliding mode control (SMC), and fuzzy logic control.

19. The system of claim 15, wherein the component determination module determines a rate of decay of the difference and the calibration module calibrates the engine control module based on the rate of decay.

20. The system of claim 15, wherein the engine control module controls the amount of fuel based on a difference between a desired composition of the exhaust gas at the second oxygen sensor and signals received from the second oxygen sensor during operation of the engine.