Pressure sensor rationality diagnostic for a dual clutch transmission

Patent metadata

Field	Value
Publication number	US-10316963-B2
Application number	US-201715496626-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Apr 25, 2017
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A pressure sensor rationality diagnostic for a dual clutch transmission includes a series of sensor tests. One such test includes charging an oil accumulator to a maximum pressure and storing the maximum pressure value. After performing a discharge pressure event and measuring the pressure value, the difference between the max pressure value and the discharge pressure value is calculated to determine if the difference is less than a predetermined threshold. If the difference is less than the predetermined threshold then at least one remedial action is performed which may include a driver alert or default charging mode. Additionally, similar sensor tests are performed to determine if faults exists and, if true, at least one remedial action is performed.

First claim

What is claimed is:

1. An accumulator oil pressure sensor rationality diagnostic for a transmission comprising:
charging an accumulator to a maximum pressure and storing the maximum pressure value before a discharge;
performing a discharge pressure event and measuring the discharge pressure value after the discharge is complete;
determining if the difference between the max pressure value and the discharge pressure value is less than a predetermined threshold; and
performing at least one remedial action when the difference is less than the predetermined difference threshold.

2. The method of claim 1 further comprising determining and storing an average maximum pressure value prior to performing a discharge pressure event.

3. The method of claim 2 wherein determining the average maximum pressure value and an average discharge pressure value further comprises calculating absolute extremum values for the average maximum pressure value and the average discharge pressure value over a predetermined average pressure period.

4. The method of claim 3 further comprising performing at least one remedial action when a difference between the average maximum pressure value and the average discharge pressure value is less than a predetermined threshold.

5. The method of claim 1 further comprising turning off an accumulator charge motor and resetting a charge timer after charging the accumulator to a maximum pressure and storing the maximum pressure value.

6. The method of claim 5 further comprising turning on the accumulator charge motor and starting the charge timer after the discharge pressure event and measuring the discharge pressure value has been performed.

7. The method of claim 6 further comprising performing at least one remedial action when the charge timer value is greater than a predetermined accumulator charge timer threshold.

8. The method of claim 6 further comprising determining and storing accumulator charge pressure upon turning on the accumulator charge motor.

9. The method of claim 8 further comprising calculating the difference between an actual accumulator charge pressure and the stored accumulator charge pressure after a predetermined accumulator charge period expires.

10. The method of claim 9 further comprising performing at least one remedial action if the difference between the actual accumulator charge pressure and the stored accumulator charge is less than a predetermined charge pressure threshold or if the difference between the actual accumulator charge pressure and the stored accumulator charge is greater than the predetermined charge pressure threshold.

11. The method of claim 6 further comprising measuring absolute extremum pressure values during a predetermined discharge period after the discharge pressure event has been performed.

12. The method of claim 11 further comprising performing at least one remedial action if the difference between the absolute extremum pressure values measured during the predetermined discharge period is less than a predetermined difference of absolute extremum pressure values expected during the predetermined discharge period.

13. An accumulator oil pressure sensor rationality diagnostic for a transmission comprising:
charging an accumulator to a maximum pressure and storing the maximum pressure value before a discharge;
determining and storing an average maximum pressure value prior to performing a discharge pressure event after the discharge is complete;
performing the discharge pressure event and measuring the discharge pressure value;
determining and storing an average discharge pressure value after performing the discharge pressure event;
determining if the difference between the max pressure value and the discharge pressure value is less than a predetermined threshold; and
performing at least one remedial action when the difference is less than the predetermined difference threshold.

14. The method of claim 13 wherein determining the average maximum pressure value and the average discharge pressure value further comprises calculating absolute extremum values for the average max pressure value and the average discharge pressure value over a predetermined average pressure period.

15. The method of claim 13 further comprising performing at least one remedial action when a difference between the average maximum pressure value and the average discharge pressure value is less than a predetermined threshold.

16. The method of claim 13 further comprising turning off an accumulator charge motor and resetting a charge timer after charging the accumulator to a maximum pressure and storing the maximum pressure value.

17. The method of claim 16 further comprising turning on the accumulator charge motor and starting the charge timer after the discharge pressure event and measuring the discharge pressure value has been performed.

18. The method of claim 17 further comprising performing at least one remedial action when the charge timer value is greater than a predetermined accumulator charge timer threshold.

19. The method of claim 18 further comprising determining and storing accumulator charge pressure upon turning on the accumulator charge motor.

20. The method of claim 19 further comprising calculating the difference between an actual accumulator charge pressure and the stored accumulator charge pressure after a predetermined accumulator charge period expires.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Tao Xuefeng T
• Mciver Jeryl
• Dion Leo P
• Perantoni Greg

Classifications

• F16H61/12 Primary

  Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures} · CPC title

• F16H2061/1212

  Plausibility checks; Counting means for repeated failures · CPC title

• F16H2061/305

  Accumulators for fluid supply to the servo motors, or control thereof · CPC title

• F16H2061/0034

  Accumulators for fluid pressure supply; Control thereof · CPC title

• F15B1/033

  with electrical control means · CPC title