Shift capacity control for automatic transmission

• US 5,665,028 A
• Filed: 02/16/1995
• Issued: 09/09/1997
• Est. Priority Date: 02/23/1994
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hayasaki, Kouichi
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): KWON, TAI CHOON
• Application Number:
  US08/389,323
• Time in Patent Office: 936 Days
• Field of Search: 477/120, 477/143, 477/148, 477/156, 477/158, 477/154, 477/155, 477/160, 364/424.1
• US Class Current: 477/143
• CPC Class Codes: B60W 2050/0057 Frequency analysis, spectral techniques or transforms
• CPC Class Codes: F16H 2061/0081 Fuzzy logic
• CPC Class Codes: F16H 2061/0087 Adaptive control, e.g. the control parameters adapted by learning
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 59/36 Inputs being a function of speed
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/72 dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: F16H 61/0437 by using electrical signals F16H61/0403 and F16H61/061 take precedence
• CPC Class Codes: F16H 61/08 Timing control

Abstract

A shift capacity control system for an automatic transmission is constructed to determine a state of an engine speed difference after occurrence of a shift command, determine a propriety of a shift capacity of the automatic transmission in response to the state determined, and control an engagement capacity of a friction element to be operated during a period of shifting in response to the propriety determined.

Claims

1. A system for controlling a shift capacity of an automatic transmission for a prime mover, the automatic transmission being shiftable by selective engagement of friction elements, the system comprising:

means for sensing a revolution of the prime mover and generating a revolution signal indicative of said revolution sensed;

means for determining a shift command to the automatic transmission and generating a shift command signal indicative of said shift command determined;

means for determining a state of a time variation in said revolution of the prime mover after said shift command signal is generated and generating a state signal indicative of said state determined;

means for determining a propriety of the shift capacity of the automatic transmission during a period of shifting thereof in response to said state signal and generating a propriety signal indicative of said propriety determined; and

means for controlling an engagement capacity of the friction element to be operated during a subsequent period of shifting in response to said propriety signal.

2. A system as claimed in claim 1, wherein said engagement capacity controlling means include means for adjusting a line pressure pertinent to engagement of an entirety of the friction elements.

3. A system as claimed in claim 2, wherein said engagement capacity controlling means include means for directly adjusting a working pressure pertinent to engagement of the friction element to be operated.

4. A system as claimed in claim 1, wherein said state determining means determine said state in accordance with a length of a shift response time between and point of said shift command and a point that said time variation is changed from negative to positive for the first time after a lapse of a first set time covering a length from said point of said shift command to completion of shifting.

5. A system as claimed in claim 1, wherein said propriety determining means determine said propriety in accordance with a fuzzy membership function of said length of said shift response time.

6. A system as claimed in claim 4, wherein said state determining means determine said state in accordance with a sum of said time variation between a point that said time variation is changed from positive to negative for the last time within said first set time and said point that said time variation is changed from negative to positive for the first time before a lapse of said second set time.

7. A system as claimed in claim 5, wherein said propriety determining means determine said propriety in accordance with a fuzzy membership function of said sum of said time variation.

8. A system as claimed in claim 6, wherein said state determining means determine said state in accordance with an incline of said time variation in the vicinity of said point that said time variation is changed from positive to negative for the last time within said first set time.

9. A system as claimed in claim 7, wherein said propriety determining means determine said propriety in accordance with a fuzzy membership function of said incline of said time variation.

10. A system as claimed in claim 9, wherein said fuzzy membership functions of said length of said shift response time, said sum of said time variation, and said incline of said time variation are determined every load of the prime mover, respectively.

11. A system as claimed in claim 1, wherein said propriety determining means determine said propriety in connection with each of a plurality of parts of said period of shifting.

12. A system as claimed in claim 11, wherein said plurality of parts of said period of shifting include former and latter halves of said period of shifting.

13. A system as claimed in claim 12, wherein said state determining means determine said state in said former half of said period of shifting in accordance with a length of said shift response time between said point of said shift command and said point that said time variation is changed from positive to negative for the last time within said first set time.

14. A system as claimed in claim 13, wherein said propriety determining means determine said propriety in said former half of said period of shifting in accordance with a fuzzy membership function of said length of said shift response time.

15. A system as claimed in claim 13, wherein said state determining means determine said state in said former half of said period of shifting in accordance with a value of said time variation at a point that a predetermined time elapsed after said point that said time variation is changed from positive to negative for the last time within said first set time.

16. A system as claimed in claim 15, wherein said propriety determining means determine said propriety in said former half of said period of shifting in accordance with a fuzzy membership function of said value of said time variation.

17. A system as claimed in claim 15, wherein said state determining means determine said state in said former half of said period of shifting in accordance with a sum of said time variation between said point of said shift command and a point that said time variation is changed from positive to negative for the last time within said first set time.

18. A system as claimed in claim 16, wherein said propriety determining means determine said propriety in said former half of said period of shifting in accordance with a fuzzy membership function of said sum of said time variation.

19. A system as claimed in claim 17, wherein said state determining means determine said state in said former half of said period of shifting in accordance with an incline of said time variation in the vicinity of said point that said time variation is changed from positive to negative for the last time within said first set time.

20. A system as claimed in claim 19, wherein said propriety determining means determine said propriety in said former half of said period of shifting in accordance with a fuzzy membership function of said incline of said time variation.

21. A system as claimed in claim 12, wherein said state determining means determine said state in said latter half of said period of shifting in accordance with an absolute value of a difference in said time variation between any two points between a point of said former half of said period of shifting and a point that said time variation is changed from negative to positive for the first time within said latter half of said period of shifting.

22. A system as claimed in claim 21, wherein said propriety determining means determine said propriety in said latter half of said period of shifting in accordance with a fuzzy membership function of said absolute value of said difference in said time variation.

23. A system as claimed in claim 21, wherein said state determining means determine said state in said latter half of said period of shifting in accordance with a value of said time variation at any point between said point of said former half of said period of shifting and a point that said time variation is changed from negative to positive at the first time in said latter half of said period of shifting.

24. A system as claimed in claim 23, wherein said propriety determining means determine said propriety in said latter half of said period of shifting in accordance with a fuzzy membership function of said value of said any point.

25. A system as claimed in claim 23, wherein said state determining means determine said state in said latter half of said period of shifting in accordance with a minimum value of said time variation between said point that said time variation is changed from positive to negative for the last time within said first set time and a point that said time variation is changed from negative to positive for the first time before a lapse of said second set time.

26. A system as claimed in claim 25, wherein said propriety determining means determine said propriety in said latter half of said period of shifting in accordance with a fuzzy membership function of said minimum value of said time variation.

27. A system as claimed in claim 25, wherein said state determining means determine said state in said latter half of said period of shifting in accordance with an incline of said time variation in the vicinity of said point that said time variation is changed from negative to positive for the first time after a lapse of said first set time, and before a lapse of said second set time.

28. A system as claimed in claim 27, wherein said propriety determining means determine said propriety in said latter half of said period of shifting in accordance with a fuzzy membership function of said incline of said time variation.

29. A method of controlling a shift capacity of an automatic transmission for a prime mover, the automatic transmission being shiftable by selective engagement of friction elements, the method comprising the steps of:

sensing a revolution of the prime mover and generating a revolution signal indicative of said revolution sensed;

determining a shift command to the automatic transmission and generating a shift command signal indicative of said shift command determined;

determining a state of a time variation in said revolution of the prime mover after said shift command signal is generated and generating a state signal indicative of said state determined;

determining a propriety of the shift capacity of the automatic transmission during a period of shifting thereof in response to said state signal and generating a propriety signal indicative of said propriety determined; and

controlling an engagement capacity of the friction element to be operated during a subsequent period of shifting in response to said propriety signal.

30. A method as claimed in claim 29, wherein said engagement capacity controlling step is carried out by adjusting a line pressure pertinent to engagement of an entirety of the friction elements.

31. A method as claimed in claim 30, wherein said engagement capacity controlling step is carried out by directly adjusting a working pressure pertinent to engagement of the friction element to be operated.

32. A method as claimed in claim 29, wherein said state determining step is carried out in accordance with a length of a shift response time between a point of said shift command and point that said time variation is changed from negative to positive for the first time after a lapse of a first set time covering a length from said point of said shift command to commencement of shifting, and before a lapse of a second set time covering a length from said point of said shift command to completion of shifting.

33. A method as claimed in claim 32, wherein said propriety determining step is carried out in accordance with a fuzzy membership function of said length of said shift response time.

34. A method as claimed in claim 32, wherein said state determining step is carried out in accordance with a sum of said time variation between a point that said time variation is changed from positive to negative for the last time within said first set time and said point that said time variation is changed from negative to positive for the first time before a lapse of said second set time.

35. A method as claimed in claim 34, wherein said propriety determining step is carried out in accordance with a fuzzy membership function of said sum of said time variation.

36. A method as claimed in claim 34, wherein said state determining step is carried out in accordance with an incline of said time variation in the vicinity of said point that said time variation is changed from positive to negative for the last time within said first set time.

37. A method as claimed in claim 36, wherein said propriety determining step is carried out in accordance with a fuzzy membership function of said incline of said time variation.

38. A method as claimed in claim 37, wherein said fuzzy membership functions of said length of said shift response time, said sum of said time variation, and said incline of said time variation are determined every load of the prime mover, respectively.

39. A method as claimed in claim 29, wherein said propriety determining step is carried out in connection with each of a plurality of parts of said period of shifting.

40. A method as claimed in claim 39, wherein said plurality of parts of said period of shifting include former and latter halves of said period of shifting.

41. A method as claimed in claim 40, wherein said state determining step is carried out in said former half of said period of shifting in accordance with a length of said shift response time between said point of said shift command and said point that said time variation is changed form positive to negative for the last time within said first set time.

42. A method as claimed in claim 41, wherein said propriety determining step is carried out in said former half of said period of shifting in accordance with a fuzzy membership function of said length of said shift response time.

43. A method as claimed in claim 41, wherein said state determining step is carried out in said former half of said period of shifting in accordance with a value of said time variation at a point that a predetermined time elapsed after said point that said time variation is changed from positive to negative for the last time within said first set time.

44. A method as claimed in claim 43, wherein said propriety determining step is carried out in said former half of said period of shifting in accordance with a fuzzy membership function of said value of said time variation.

45. A method as claimed in claim 43, wherein said state determining step is carried out in said former half of said period of shifting in accordance with a sum of said time variation between said point of said shift command and a point that said time variation is changed form positive to negative for the last time within said first set time.

46. A method as claimed in claim 45, wherein said propriety determining step is carried out in said former half of said period of shifting in accordance with a fuzzy membership function of said sum of said time variation.

47. A method as claimed in claim 45, wherein said state determining step is carried out in said former half of said period of shifting in accordance with an incline of said time variation in the vicinity of said point that said time variation is changed from positive to negative for the last time within said first set time.

48. A method as claimed in claim 47, wherein said propriety determining step is carried out in said former half of said period of shifting in accordance with a fuzzy membership function of said incline of said time variation.

49. A method as claimed in claim 47, wherein said state determining step is carried out in said latter half of said period of shifting in accordance with an absolute value of a difference in said time variation between any two points between a point of said former half of said period of shifting and a point that said time variation is changed from negative to positive for the first time within said latter half of said period of shifting.

50. A method as claimed in claim 49, wherein said propriety determining step is carried out in said latter half of said period of shifting in accordance with a fuzzy membership function of said absolute value of said difference in said time variation.

51. A method as claimed in claim 49, wherein said state determining step is carried out in said latter half of said period of shifting in accordance with a value of said time variation at any point between said point of said former half of said period of shifting and a point that said time variation is changed from negative to positive at the first time in said latter half of said period of shifting.

52. A method as claimed in claim 51, wherein said propriety determining step is carried out in said latter half of said period of shifting in accordance with a fuzzy membership function of said value of said any point.

53. A method as claimed in claim 51, wherein said state determining step is carried out in said latter half of said period of shifting in accordance with a minimum value of said time variation between said point that said time variation is changed from positive to negative for the last time within said first set time and a point that said time variation is changed from negative to positive for the first time before a lapse of said second set time.

54. A method as claimed in claim 53, wherein said propriety determining step is carried out in said latter half of said period of shifting in accordance with a fuzzy membership function of said minimum value of said time variation.

55. A method as claimed in claim 53, wherein said state determining step is carried out in said latter half of said period of shifting in accordance with an incline of said time variation in the vicinity of said point that said time variation is changed from negative to positive for the first time after a lapse of said first set time, and before a lapse of said second set time.

56. A method as claimed in claim 55, wherein said propriety determining step is carried out in said latter half of said period of shifting in accordance with a fuzzy membership function of said incline of said time variation.

57. A system for controlling a shift capacity of an automatic transmission for a prime mover, the automatic transmission for a prime mover, the automatic transmission being shiftable by selective engagement of friction elements, the system comprising:

means for sensing a revolution of the prime mover and generating a revolution signa indicative of said revolution sensed;

means for determining a shift command to the automatic transmission and generating a shift command signal indicative of said shift command determined;

means for determining a time variation in said revolution of the prime mover after said shift command signal is generated and generating a time variation signal indicative of said time variation determined;

means for determining a propriety of the shift capacity of the automatic transmission during a period of shifting thereof in response to said time variation signal and generating a propriety signal indicative of said propriety determined; and

means for controlling an engagement capacity of the friction element to be operated during a subsequent period of shifting in response to said propriety signal.

58. A method of controlling a shift capacity of an automatic transmission for a prime mover, the automatic transmission being shiftable by selective engagement of friction elements, the method comprising the steps of:

sensing a revolution of the prime mover and generating a revolution signal indicative of said revolution sensed;

determining a shift command to the automatic transmission and generating a shift command signal indicative of said shift command determined;

determining a time variation in said revolution of the prime mover after said shift command signal is generated and generating a time variation signal indicative of said time variation determined;

determining a propriety of the shift capacity of the automatic transmission during a period of shifting thereof in response to said time variation signal and generating a propriety signal indicative of said propriety determined; and

controlling an engagement capacity of the friction element to be operated during a subsequent period of shifting in response to said propriety signal.

59. A system for controlling a shift capacity of an automatic transmission for a prime mover, the automatic transmission being shiftable by selective engagement of friction elements, the system comprising;

means for sensing a revolution of the prime mover and generating a revolution signal indicative of said revolution sensed;

means for determining a shift command to the automatic transmission and generating a shift command signal indicative of said shift command determined;

means for determining a state of a time variation in said revolution of the prime mover after said shift command signal is generated and generating a state signal indicative of said state determined, said state determining means determining said state in accordance with a length of a shift response time between a point of said shift command and a point that said time variation is changed from a negative to positive for the first time after a lapse of a first set time covering a length from said point of said shift command to commencement of shifting, and before a lapse of a second set time covering a length from said point of said shift command to completion of shifting;

means for determining a propriety of the shift capacity of the automatic transmission during a period of shifting thereof in response to said state signal and generating a propriety signal indicative of said propriety determined; and

means for controlling an engagement capacity of the friction element to be operated during a period of shifting of the automatic transmission in response to said propriety signal.

60. A method of controlling a shift capacity of an automatic transmission for a prime mover, the automatic transmission for a prime mover, the automatic transmission being shiftable by selective engagement of friction elements, the method comprising the steps of:

sensing a revolution of the prime mover and generating a revolution signal indicative of said revolution sensed;

determining a shift command to the automatic transmission and generating a shift command signal indicative of said shift command determined;

determining a state of a time variation in said revolution of the prime mover after said shift command signal is generated and generating a state signal indicative of said state determined, said state determining step being carried out in accordance with a length of a shift response time between a point of said shift command and a point that said time variation is changed form negative to positive for the first time after a lapse of a first set time covering a length from said point of said shift command to commencement of shifting, and before a lapse of a second set time covering a length from said point of said shift command to completion of shifting;

determining a propriety of the shift capacity of the automatic transmission during a period of shifting thereof in response to said state signal and generating a propriety signal indicative of said propriety determined; and

controlling an engagement capacity of the friction element to be operated during a period of shifting of the automatic transmission in response to said propriety signal.