Method and apparatus to evaluate a starting system for an internal combustion engine

• US 8,818,611 B2
• Filed: 08/15/2011
• Issued: 08/26/2014
• Est. Priority Date: 08/15/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Shin, Kwang-Keun, Salman, Mutasim A.
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Sample, Jonathan L
• Application Number:
  US13/209,595
• Publication Number:
  US 20130046435A1
• Time in Patent Office: 1,107 Days
• Field of Search: 701 291- 344
• US Class Current: 701/29.1
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02N 11/08 Circuits or control means specially adapted for starting of engines
• CPC Class Codes: F02N 11/108 for diagnosis of the starter or its components
• CPC Class Codes: F02N 15/06 the toothed gears being moved by axial displacement
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2200/023 Engine temperature
• CPC Class Codes: F02N 2200/043 Starter voltage
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: F02N 2200/063 Battery voltage
• CPC Class Codes: F02N 2200/064 Battery temperature

Abstract

A starting system for an internal combustion engine includes a starter motor and a battery. A method for evaluating the starting system includes detecting a fault associated with the starter motor when a minimum starting system voltage during a cranking event is greater than a threshold minimum starting system voltage determined in relation to an engine acceleration parameter, and detecting a fault associated with the battery when the engine acceleration parameter is less than a minimum threshold for the engine acceleration parameter.

Claims

1. A control module-implemented method for evaluating a starting system for an internal combustion engine, the starting system including a starter motor and a battery, comprising:

monitoring engine speed, cranking time, and battery voltage during an engine cranking event, said engine cranking event comprising the engine speed increasing from an engine speed of zero to an engine speed threshold;

detecting and distinguishing, via a control module, between first and second faults resulting in a non-start event of the engine, wherein detecting the first and second faults comprises;

detecting the first fault associated with the starter motor when a minimum starting system voltage during the cranking event is greater than a threshold minimum starting system voltage determined in relation to an engine acceleration parameter, wherein the engine acceleration parameter is calculated by dividing the engine speed threshold by the cranking time for the engine speed to achieve the engine speed threshold; and

only if the first fault associated with the starter motor is not detected, detecting the second fault associated with the battery when the engine acceleration parameter is less than a minimum threshold for the engine acceleration parameter during the cranking event.

2. The method of claim 1, wherein said cranking event comprises an engine speed increasing from an engine speed of 0 RPM to a preset engine speed threshold.

3. The method of claim 2, wherein the preset engine speed threshold comprises 200 RPM and the engine acceleration parameter comprises an average engine acceleration during the cranking event.

4. The method of claim 1, further comprising determining the starter motor and the battery are functioning as intended when the engine acceleration parameter is greater than the minimum threshold for the engine acceleration parameter.

5. The method of claim 1, wherein detecting the fault associated with the battery when the engine acceleration parameter is less than the minimum threshold for the engine acceleration parameter comprises detecting a battery fault when a battery state-of-charge during the cranking event is greater than a threshold battery state-of-charge.

6. The method of claim 5, wherein detecting the battery fault comprises detecting a low state-of-charge of the battery.

7. The method of claim 1, wherein detecting the fault associated with the battery when the engine acceleration parameter is less than the minimum threshold for the engine acceleration parameter comprises detecting a battery fault when a battery state-of-charge during the cranking event is less than a threshold battery state-of-charge.

8. The method of claim 7, wherein detecting the battery fault when the battery state-of-charge during the cranking event is less than the threshold battery state-of-charge comprises detecting a low state-of-health of the battery.

9. A control module-implemented method for evaluating a starting system for an internal combustion engine, the starting system including a starter motor and a battery, comprising:

cranking the engine, said cranking comprising increasing the engine speed from an engine speed of zero to an engine speed threshold;

monitoring engine speed, cranking time, and battery voltage during engine cranking;

determining an engine acceleration parameter by dividing the engine speed threshold by the cranking time for the engine speed to achieve the engine speed threshold;

determining a minimum battery voltage during engine cranking; and

detecting and distinguishing, via a control module, between first and second faults resulting in a non-start event of the engine, wherein detecting the first and second faults comprises;

detecting the first fault associated with the starter motor only when the minimum battery voltage during engine cranking is greater than a threshold cranking voltage corresponding to the engine acceleration parameter; and

only if the first fault associated with the starter motor is not detected, detecting the second fault associated with the battery when the engine acceleration parameter is less than a minimum threshold for the engine acceleration parameter.

10. The method of claim 9, further comprising determining a state-of-charge of the battery, wherein detecting the fault associated with the battery when the engine acceleration parameter is less than the minimum threshold for the engine acceleration parameter comprises:

detecting a first fault associated with the battery when the state-of-charge of the battery is greater than a state-of-charge threshold; and

detecting a second fault associated with the battery when the state-of-charge of the battery is less than the state-of-charge threshold.

11. The method of claim 10, wherein the state-of-charge threshold is determined in relation to a temperature of the battery.

12. A control module-implemented method for evaluating a starting system for an internal combustion engine, the starting system including a starter motor and a battery, comprising:

cranking the engine, said cranking comprising increasing the engine speed from an engine speed of zero to an engine speed threshold;

monitoring engine speed, cranking time, and battery voltage during engine cranking;

determining an engine acceleration parameter by dividing the engine speed threshold by the cranking time for the engine speed to achieve the engine speed threshold;

determining a minimum battery voltage during engine cranking; and

detecting and distinguishing, via a control module, between first and second faults resulting in a non-start event of the engine, wherein detecting the first and second faults comprises;

detecting the first fault associated with the starter motor when a minimum starting system voltage during the cranking event is greater than a threshold minimum starting system voltage determined in relation to the engine acceleration parameter; and

only if the first fault associated with the starter motor is not detected, detecting a fault associated with the battery only when the minimum battery voltage during engine cranking is less than a threshold cranking voltage corresponding to the engine acceleration parameter and the engine acceleration parameter is less than a minimum threshold for the engine acceleration parameter during the cranking event.

13. The method of claim 12, wherein detecting the fault associated with the battery comprises detecting a battery fault when a battery state-of-charge during engine cranking is greater than a threshold battery state-of-charge.

14. The method of claim 13, wherein detecting the battery fault comprises detecting a low state-of-charge of the battery.

15. The method of claim 12, wherein detecting the fault associated with the battery comprises detecting a battery fault when a battery state-of-charge during engine cranking is less than a threshold battery state-of-charge.

16. The method of claim 15, wherein detecting the second battery fault comprises detecting a low state-of-health of the battery.

17. The method of claim 12, further comprising determining the starter motor and the battery are functioning as intended when the engine acceleration parameter is greater than the minimum threshold for the engine acceleration parameter.