Apparatus and method for determining remaining transmission oil life

• US 8,050,814 B2
• Filed: 01/24/2008
• Issued: 11/01/2011
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Rains, Mark A., Caldwell, Brett R.
• Primary Examiner(s): Jayne; Darnell
• Assistant Examiner(s): RODDEN, JOSHUA E
• Application Number:
  US12/018,833
• Publication Number:
  US 20080228339A1
• Time in Patent Office: 1,377 Days
• Field of Search: 701/29, 701/30, 701/51, 340/438, 340/439, 340/457.4, 73/530.5, 73/540.1
• US Class Current: 701/30
• CPC Class Codes: F16H 57/04 Features relating to lubrication or cooling or heatingin hydrokinetic gearing F16H41/30; control of lubrication or cooling in hydrostatic gearing F16H61/4165
• CPC Class Codes: G01N 33/2888 Lubricating oil characteristics, e.g. deterioration lubricating properties G01N33/30

Abstract

An improved method for predicting the remaining useful life of transmission oil and an apparatus for practicing the same are provided. The method includes: detecting if the transmission has completed a new shift; if yes, determining a total shift count; determining accumulated distance and accumulated time parameters; determining a transmission temperature degradation factor; detecting if the lockup clutch is open and if the transmission is in range; if yes, determining a converter degradation factor; determining a total degradation factor based at least in part upon the transmission temperature degradation factor and converter degradation factor; determining an oil life time limit and oil life distance limit; determining if either the accumulated time parameter is greater than the oil life time limit or the accumulated distance parameter is greater than the oil life distance limit; if yes, activating a service indicator to notify vehicle occupants that transmission oil service is required.

Claims

1. A method for determining the remaining useful life of oil in a transmission having a torque converter with a lockup clutch, the method comprising:

detecting if the transmission has completed a new shift;

determining a total shift count if said new shift has been completed;

determining an accumulated time parameter;

determining an accumulated distance parameter;

determining a transmission temperature degradation factor based at least in part upon the accumulated time parameter;

determining a total degradation factor based at least in part upon said transmission temperature degradation factor;

determining an oil life time limit based at least in part upon said total degradation factor;

the total shift count, and the accumulated time parameter

determining if said accumulated time parameter is greater than said oil life time limit;

determining an oil life distance limit based at least in part upon said total degradation factor;

the total shift count, and the accumulated distance parameter

determining if said accumulated distance parameter is greater than said oil life distance limit; and

activating a service indicator configured to signal that transmission oil service is required in response to at least one of said accumulated time parameter being greater than said oil life time limit and said accumulated distance parameter being greater than said oil life distance limit.

2. The method of claim 1, wherein said determining a transmission temperature degradation factor is based at least in part upon a transmission temperature fuzzy timer parameter.

3. The method of claim 1, further comprising:

detecting if the lockup clutch is open and the transmission is in range; and

determining a converter degradation factor if the lockup clutch is open and the transmission is in range;

wherein said determining a total degradation factor is further based at least in part upon said converter degradation factor.

4. The method of claim 3, wherein said determining a converter degradation factor is based at least in part upon a converter fuzzy timer parameter.

5. The method of claim 1, further comprising:

detecting if a transmission retarder is present; and

determining a retarder present degradation factor if said transmission retarder is present;

wherein said determining a total degradation factor is further based at least in part upon said retarder present degradation factor.

6. The method of claim 5, further comprising:

detecting if said transmission retarder is active; and

determining a retarder active degradation factor if said transmission retarder is active;

wherein said determining a total degradation factor is further based at least in part upon said retarder active degradation factor.

7. The method of claim 6, wherein said determining a retarder active degradation factor is based at least in part upon a retarder fuzzy miles parameter.

8. The method of claim 5, further comprising:

detecting if a retarder accumulator is applied; and

determining an accumulator degradation factor if said accumulator is applied;

wherein said determining a total degradation factor is further based at least in part upon said accumulator degradation factor.

9. The method of claim 1, further comprising:

determining at least one of a remaining useful distance of the transmission oil based at least in part upon said accumulated distance parameter and a remaining useful time of the transmission oil based at least in part upon said accumulated time parameter.

10. The method of claim 9, wherein said service indicator is further configured to selectively communicate at least one of said remaining useful distance and said remaining useful time of the transmission oil to vehicle occupants.

11. A method for determining the remaining useful life of transmission oil in a motorized vehicle including a power transmission having a torque converter with a lockup clutch, the method including:

detecting if the transmission has completed a new shift;

determining a total shift count when said new shift has been completed;

determining an accumulated distance parameter;

determining an accumulated time parameter;

monitoring a transmission temperature;

determining a transmission temperature degradation factor based at least in part upon the transmission temperature, and the accumulated time parameter;

detecting if the lockup clutch is open and if the transmission is in range;

determining a converter degradation factor if the lockup clutch is open and the transmission is in range;

determining a total degradation factor based at least in part upon said transmission temperature degradation factor and said converter degradation factor;

determining an oil life time limit and an oil life distance limit each based at least in part upon said total degradation factor and said total shift count;

determining if at least one of said accumulated time parameter is greater than said oil life time limit and said accumulated distance parameter is greater than said oil life distance limit; and

activating a service indicator configured to notify vehicle occupants that transmission oil service is required in response to at least one of said accumulated time parameter being greater than said oil life time limit and said accumulated distance parameter being greater than said oil life distance limit.

12. The method of claim 11, wherein said determining a transmission temperature degradation factor is based at least in part upon a transmission temperature fuzzy timer parameter, and said determining a converter degradation factor is based at least in part upon a converter fuzzy timer parameter.

13. The method of claim 11, further comprising:

detecting if a transmission retarder is present; and

determining a retarder present degradation factor if said transmission retarder is present;

wherein said determining a total degradation factor is further based at least in part upon said retarder present degradation factor.

14. The method of claim 13, further comprising:

detecting if said transmission retarder is active; and

determining a retarder active degradation factor based at least in part upon a retarder fuzzy miles parameter if said transmission retarder is active;

wherein said determining a total degradation factor is further based at least in part upon said retarder active degradation factor.

15. The method of claim 13, further comprising:

detecting if a retarder accumulator is applied;

determining a total number of accumulator applies; and

determining an accumulator degradation factor based at least in part upon said total number of accumulator applies;

wherein said determining a total degradation factor is further based at least in part upon said accumulator degradation factor.

16. The method of claim 11, further comprising:

determining at least one of a remaining useful distance of the transmission oil based at least in part upon said accumulated distance parameter and a remaining useful time of the transmission oil based at least in part upon said accumulated time parameter;

wherein said service indicator is further configured to selectively communicate at least one of said remaining useful distance and said remaining useful time of the transmission oil to vehicle occupants.

17. A control apparatus for a motorized vehicle with a transmission having a torque converter with a lockup clutch and a reservoir fluidly coupled to and configured for supplying transmission oil to the power transmission, the control apparatus comprising:

a controller in operative communication with the power transmission;

at least one sensing device operatively connected to said controller and configured to monitor a plurality of transmission degradation factors; and

a service indicator operatively connected to said controller and configured to signal that transmission oil service is required;

wherein said controller is programmed and configured to determine an accumulated time parameter and accumulated distance parameter, detect if the transmission has completed a new shift, and determine a total shift count if said new shift has been completed;

wherein said plurality of transmission degradation factors are based at least in part upon at least one of the accumulated time parameter, and the accumulated distance parameter;

wherein said controller is programmed and configured to determine a total degradation factor based at least in part upon said plurality of transmission degradation factors;

wherein said controller is programmed and configured to determine an oil life time limit and an oil life distance limit based at least in part upon said total degradation factor and said total shift count;

wherein said controller is programmed and configured to determine if at least one of said accumulated time parameter is greater than said oil life time limit and said accumulated distance parameter is greater than said oil life distance limit; and

wherein said controller activates said service indicator in response to at least one of said accumulated time parameter being greater than said oil life time limit and said accumulated distance parameter being greater than said oil life distance limit.

18. The control apparatus of claim 17, wherein said plurality of transmission degradation factors includes a transmission temperature degradation factor, a converter degradation factor, a retarder present degradation factor, a retarder active degradation factor, and an accumulator degradation factor.

19. The control apparatus of claim 17, wherein said controller is further programmed and configured for determining at least one of a remaining useful distance of said transmission oil in response to said accumulated distance parameter and a remaining useful time of said transmission oil in response to said accumulated time parameter;

wherein said service indicator device is configured to selectively display said remaining useful distance and said remaining useful time to vehicle occupants.