Closed loop control with bias voltage toggle

• US 7,954,365 B2
• Filed: 05/04/2009
• Issued: 06/07/2011
• Est. Priority Date: 12/23/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Emmorey, Michael S., White, Vincent A., Treumuth, Paul E.
• Primary Examiner(s): Kirkland, III; Freddie
• Application Number:
  US12/434,949
• Publication Number:
  US 20100154525A1
• Time in Patent Office: 764 Days
• Field of Search: 731/147.3
• US Class Current: 73/114.73
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence
• CPC Class Codes: F02D 41/1455 with sensor resistivity varying with oxygen concentration F02D41/1456 takes precedence
• CPC Class Codes: F02D 41/1476 Biasing of the sensor

Abstract

An oxygen sensor circuit comprises an oxygen sensor, a bias voltage module, and a switch module. The bias voltage module communicates with the oxygen sensor and generates a bias voltage. The switch module selectively connects the bias voltage module to the oxygen sensor.

Claims

1. An oxygen sensor circuit comprising:

an oxygen sensor;

a bias voltage module that generates a bias voltage; and

a switch module that disconnects said bias voltage module from said oxygen sensor for a period beginning at startup of an engine and that selectively connects said bias voltage module in parallel with said oxygen sensor after said period.

2. The oxygen sensor circuit of claim 1 wherein said switch module connects said bias voltage module to said oxygen sensor periodically after said period.

3. The oxygen sensor circuit of claim 1 wherein said period is a predetermined period.

4. The oxygen sensor circuit of claim 1 further comprising a sensor monitoring module that compares at least one parameter of said oxygen sensor and a predetermined oxygen sensor value, wherein said switch module connects said bias voltage module to said oxygen sensor based on said comparison.

5. The oxygen sensor circuit of claim 4 wherein said at least one parameter includes voltage, wherein said switch module connects said bias voltage module to said oxygen sensor after said voltage is equal to said predetermined oxygen sensor value.

6. The oxygen sensor circuit of claim 4 wherein said comparison includes a predetermined period of time from the startup of the engine, wherein said switch module connects said bias voltage module to said oxygen sensor based on said comparison.

7. The oxygen sensor circuit of claim 4 wherein said switch module connects said bias voltage module to said oxygen sensor continuously based on said comparison.

8. The oxygen sensor circuit of claim 4 wherein said switch module connects said bias voltage module to said oxygen sensor periodically based on said comparison.

9. An oxygen sensor control method comprising:

communicating with an oxygen sensor;

generating a bias voltage using a bias voltage module;

disconnecting said bias voltage module from said oxygen sensor for a period beginning at startup of an engine; and

selectively connecting said bias voltage module in parallel with said oxygen sensor after said period.

10. The oxygen sensor control method of claim 9 further comprising connecting said bias voltage module to said oxygen sensor periodically after said period.

11. The oxygen sensor control method of claim 9 wherein said period is a predetermined period.

12. The oxygen sensor control method of claim 9 further comprising:

comparing at least one parameter of said oxygen sensor and a predetermined oxygen sensor value; and

connecting said bias voltage module to said oxygen sensor based on said comparison.

13. The oxygen sensor control method of claim 12 further comprising connecting said bias voltage module to said oxygen sensor after said predetermined oxygen sensor value is equal to said at least one parameter, wherein said at least one parameter includes voltage.

14. The oxygen sensor control method of claim 12 further comprising connecting said bias voltage module to said oxygen sensor based on said comparison, wherein said comparison includes a predetermined period of time from the startup of the engine.

15. The oxygen sensor control method of claim 12 further comprising connecting said bias voltage module to said oxygen sensor continuously based on said comparison.

16. The oxygen sensor control method of claim 12 further comprising connecting said bias voltage module to said oxygen sensor periodically based on said comparison.

17. An oxygen sensor circuit comprising:

an oxygen sensor;

a bias voltage module that communicates with said oxygen sensor and generates a bias voltage;

a switch module that selectively connects said bias voltage module to said oxygen sensor; and

a sensor monitoring module that compares at least one parameter of said oxygen sensor and a predetermined oxygen sensor value,

wherein said switch module connects said bias voltage module to said oxygen sensor based on said comparison,

wherein said at least one parameter includes voltage, and

wherein said switch module connects said bias voltage module to said oxygen sensor after said voltage is equal to said predetermined oxygen sensor value.

18. An oxygen sensor control method comprising:

communicating with an oxygen sensor;

generating a bias voltage using a bias voltage module;

selectively connecting said bias voltage module to said oxygen sensor;

comparing at least one parameter of said oxygen sensor and a predetermined oxygen sensor value; and

connecting said bias voltage module to said oxygen sensor based on said comparison; and

connecting said bias voltage module to said oxygen sensor after said predetermined oxygen sensor value is equal to said at least one parameter, wherein said at least one parameter includes voltage.