Claims
- 1. A method of operating a vehicle drive system comprising the steps of:
- sensing and providing a first signal representing a first speed of a first drive line,
- sensing and providing a second signal representing a second speed of a second drive line,
- determining an average and an instantaneous speed difference between said first speed signal and said second speed signal over a predetermined time period,
- determining a speed of a slower of said two speeds,
- comparing said average and said instantaneous speed differences to said speed of said slower of said two speeds, and
- sequentially providing a first output signal to a modulating clutch and a second output signal to a lock up clutch in response to both said average speed difference and said instantaneous speed difference exceeding respective predetermined values related to said speed of said slower of said two sensed speeds.
- 2. The method of claim 1 wherein said modulating clutch and said lock up clutch operably couple said first and said second drive lines.
- 3. The method of claim 1 wherein said predetermined time period is five minutes.
- 4. The method of claim 1 wherein said average speed difference is between 5 percent and 15 percent of said slower of said two sensed speeds.
- 5. The method of claim 1 wherein said maximum instantaneous speed difference is between 15 percent and 45 percent of said slower of said two sensed speeds.
- 6. The method of claim 1 wherein said modulating clutch is disengaged after a period of approximately five minutes.
- 7. The method of claim 1 wherein said determining and comparing steps are achieved by a microcontroller.
- 8. The method of claim 1 further including the step of providing a transfer case operably disposed between said drive lines and including said clutches.
- 9. A method of operating a vehicle drive system comprising the steps of:
- providing a first signal representing a first speed of a first motor vehicle drive line,
- providing a second signal representing a second speed of a second motor vehicle drive line,
- determining an average and an instantaneous speed difference between said first speed signal and said second speed signal over a predetermined time period,
- determining a speed of a slower of said two speeds,
- comparing said average and said instantaneous speed differences to said speed of said slower of said two speeds, and
- providing a first output signal adapted to ramp up a modulating clutch and a second output signal adapted to engage a lock up clutch in response to both said average speed difference and said instantaneous speed difference exceeding respective predetermined values related to said speed of said slower of said two sensed speeds.
- 10. The method of claim 9 wherein said modulating clutch and said lock up clutch operably couple said first and said second drive lines.
- 11. The method of claim 9 wherein said predetermined time period is five minutes.
- 12. The method of claim 9 wherein said average speed difference is between 5 percent and 15 percent of said slower of said two sensed speeds.
- 13. The method of claim 9 wherein said maximum instantaneous speed difference is between 15 percent and 45 percent of said slower of said two sensed speeds.
- 14. The method of claim 9 wherein said modulating clutch is disengaged after a period of approximately five minutes.
- 15. The method of claim 9 wherein said determining and comparing steps are achieved by a microcontroller.
- 16. A method of operating a vehicle drive system comprising the steps of:
- sensing a first signal representing a first speed of a first drive line,
- sensing a second signal representing a second speed of a second drive line,
- providing a microcontroller which receives said first and said second signals and
- determines an average and an instantaneous speed difference between said first speed signal and said second speed signal over a predetermined time period,
- determines a speed of a slower of said two of said sensed speeds,
- compares said average and said instantaneous speed differences to said speed of said slower of said two sensed speed, and
- provides a first output signal to a modulating clutch and a second output signal to a lock up clutch in response to both said average speed difference and said instantaneous speed difference exceeding respective predetermined values related to said speed of said slower of said two sensed speeds.
- 17. The method of claim 16 wherein said modulating clutch and said lock up clutch operably couple said first and said second drive lines.
- 18. The method of claim 16 wherein said predetermined time period is five minutes.
- 19. The method of claim 16 wherein said average speed difference is between 5 percent and 15 percent of said slower of said two sensed speeds.
- 20. The method of claim 16 wherein said maximum instantaneous speed difference is between 15 percent and 45 percent of said slower of said two sensed speeds.
Parent Case Info
This application is a divisional application of Ser. No. 08/996,805, filed Dec. 23, 1997 now U.S. Pat. No. 5,980,415, granted Nov. 9, 1999 which, in turn, is a divisional application of Ser. No. 08/570,450, filed Dec. 11, 1995 now U.S. Pat. No. 5,704,444 granted Jan. 6, 1998.
US Referenced Citations (17)
Divisions (2)
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Number |
Date |
Country |
Parent |
996805 |
Dec 1997 |
|
Parent |
570450 |
Dec 1995 |
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