Low power control system and method for a power delivery system having a continuously variable ratio transmission

• US 4,598,611 A
• Filed: 05/29/1984
• Issued: 07/08/1986
• Est. Priority Date: 05/21/1982
• Status: Expired due to Term

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Frank, Andrew A.
• Primary Examiner(s): Dorner, Kenneth J.
• Assistant Examiner(s): Wright, Dirk
• Application Number:
  US06/614,755
• Time in Patent Office: 770 Days
• Field of Search: 74/866, 74/860, 74/877, 74/859, 74/857, 123/339, 123/333, 123/436, 364/424.1
• US Class Current: 477/39
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/101 Infinitely variable gearings
• CPC Class Codes: B60W 10/107 with endless flexible members
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38
• CPC Class Codes: F16H 61/66254 controlling of shifting being influenced by a signal derived from the engine and the main coupling

Abstract

A control system and method for a power delivery system, such as that of an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for low fuel consumption. Engine fuel requirements (e.g., throttle position) are a function of at least measured engine speed, and are adjusted in accordance with any load placed on the engine so that, during low power operation, fuel flow is increased when a decrease in operating speed occurs, and fuel flow is reduced when an increase in operating speed occurs. The speed of the engine is therefore regulated in accordance with the load placed thereon. Reduction of transmission ratio effects vehicle acceleration in this mode, while an increase in transmission ratio effects vehicle deceleration.

Where a clutch or other type of variable engagement coupling is employed, the engine still is independently regulated in accordance with the fuel function even when the clutch is slipping. During the clutch slipping phase, the transmission preferably is held at a substantially constant high reduction ratio, while vehicle acceleration and deceleration are effected simply by varying the degree of engagement of the clutch.

Claims

1. A method of controlling the low power operation of a power delivery system including a prime mover and a continuously variable ratio transmission coupled to the prime mover for delivering power from the prime mover to an output shaft, the prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, the method comprising the steps of:

measuring the speed of the prime mover;

predetermining a fuel function defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed;

controlling the fuel delivery means only in accordance with said fuel function, whereby the speed of the prime mover is regulated in accordance with the load placed thereon; and

commanding desired performance of the power delivery system by reducing the transmission ratio to command an increase in power output and increasing the transmission ratio to command a reduction in power output.

2. A method according to claim 1 wherein said fuel function is the ideal operating line for minimum fuel consumption.

3. A method according to claim 1 wherein the prime mover is the engine of an engine-driven vehicle.

4. A method according to claim 3 wherein the engine is an internal combustion engine.

5. A method according to claim 4 wherein said fuel function is the ideal operating line for minimum fuel consumption.

6. A method according to claim 1 or 4 wherein said fuel function defines desired fuel requirements as a function of prime mover operating speed and measured fuel flow.

7. A method according to claim 6 wherein said fuel function is given by

8. A method according to claim 1 or 4 wherein said fuel function prescribes that the prime mover operate substantially at constant speed.

9. A method according to claim 8 where said fuel function prescribes that the prime mover operate substantially at the no-load idle speed thereof.

10. A method according to claim 9 wherein said fuel function defines a rate of change of fuel flow and is given by

11. A method according to claim 1 or 4 wherein said fuel function prescribes that the prime mover operate at or below the no-load idle speed thereof.

12. A method according to claim 11 wherein said fuel function is given by

13. A system for controlling the low power operation of a power delivery system including a prime mover and a continuously variable ratio transmission coupled to the prime mover for delivering power from the prime mover to an output shaft, the prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, the control system comprising:

speed measuring means for measuring the speed of the prime mover;

fuel function means defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed;

fuel control means operatively coupled to the fuel delivery means and to said speed measuring means and said fuel function means for controlling the fuel delivery means only in accordance with said fuel function, whereby the speed of the prime mover is regulated in accordance with the load placed thereon; and

command means operatively coupled to the transmission for commanding desired performance of the power delivery system by reducing the transmission ratio to increase power output and increasing the transmission ratio to reduce power output.

14. A system according to claim 13 wherein said fuel function is the ideal operating line for minimum fuel consumption.

15. A system according to claim 13 wherein the prime mover is the engine of an engine-driven vehicle.

16. A system according to claim 15 wherein the engine is an internal combustion engine.

17. A system according to claim 16 wherein said fuel function is the ideal operating line for minimum fuel consumption.

18. A system according to claim 13 or 16 wherein said fuel function defines desired fuel requirements as a function of prime mover operating speed and measured fuel flow.

19. A system according to claim 18 wherein said fuel function is given by

20. A system according to claim 13 or 16 wherein said fuel function prescribes that the prime mover operate substantially at constant speed.

21. A system according to claim 20 where said fuel function prescribes that the prime mover operate substantially at the no-load idle speed thereof.

22. A system according to claim 21 wherein said fuel function defines a rate of change of fuel flow and is given by

23. A system according to claim 13 or 16 wherein said fuel function prescribes that the prime mover operate at or below the no-load idle speed thereof.

24. A system according to claim 23 wherein said fuel function is given by

25. A method of controlling the operation of a power delivery system operable over a power output spectrum consisting of a low power range and a high power range, the system including a prime mover and a continuously variable ratio transmission coupled to the prime mover for delivering power from the prime mover to an output shaft, the prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, the method comprising the steps of:

during operation in the low power range, commanding desired performance of the power delivery system by reducing the transmission ratio to command an increase in power output and increasing the transmission ratio to command a reduction in power output;

during operation in the high power range, commanding desired performance of the power delivery system by increasing the transmission ratio to command an increase in power output and reducing the transmission ratio to command a reduction in power output;

measuring the speed of the prime mover;

predetermining a fuel function defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing in the low power range an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed, and prescribing in the high power range an increased fuel flow for an increase in operating speed and a reduced fuel flow for a decrease in operating speed; and

controlling said fuel delivery means only in accordance with the fuel function, whereby the speed of the prime mover is regulated in the low power range in accordance with the load placed thereon, an varies directly in accordance with commanded system performance in the high power range.

26. A method according to claim 25 wherein said fuel function is the ideal operating line for minimum fuel consumption.

27. A method according to claim 25 wherein the prime mover is the engine of an engine-driven vehicle.

28. A method according to claim 27 wherein the engine is an internal combustion engine.

29. A method according to claim 28 wherein said fuel function is the ideal operating line for minimum fuel consumption.

30. A method according to claim 25 or 28 wherein said fuel function defines desired fuel requirements for the low power range as a function of prime mover operating speed and measured fuel flow.

31. A method according to claim 30 wherein said fuel function for the low power range is given by

32. A method according to claim 25 or 28 wherein said fuel function prescribes for the low power range that the prime mover operate substantially at constant speed.

33. A method according to claim 32 where said fuel function prescribes for the low power range that the prime mover operate substantially at the no-load idle speed thereof.

34. A method according to claim 33 wherein said fuel function defines for the low power range a rate of change of fuel flow and is given by

35. A method according to claim 25 or 28 wherein said fuel function prescribes for the low power range that the prime mover operate at or below the no-load idle speed thereof.

36. A method according to claim 35 wherein said fuel function for the low power range is given by

37. A power delivery system operable over a power output spectrum consisting of a low power range and a high power range, the system comprising:

a prime mover;

a continuously variable ratio transmission coupled to said prime mover;

an output shaft coupled to said transmission for receiving power from said prime mover through said transmission;

fuel delivery means for delivering a variable quantity of fuel to said prime mover;

command means operatively coupled to said transmission for commanding a desired power delivery system performance, said command means operative in the low power range to reduce the transmission ratio to increase power output and to increase the transmission ratio to reduce power output, and operative in the high power range to increase the transmission ratio to increase power output and to reduce the transmission ratio to reduce power output;

speed measuring means for measuring the speed of said prime mover;

fuel function means defining desired fuel requirements for said prime mover in relation to at least prime mover operating speed, said fuel function prescribing in the low power range an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed, and prescribing in the high power range an increased fuel flow for an increase in operating speed and a reduced fuel flow for a decrease in operating speed; and

fuel control means operatively coupled to said fuel delivery means, said speed measuring means and said fuel function means for controlling said fuel delivery means in only accordance with said fuel function, whereby the speed of said prime mover is regulated in the low power range in accordance with the load placed thereon, and varies directly in the high power range in accordance with commanded system performance.

38. A system according to claim 37 wherein said fuel function is the ideal operating line for minimum fuel consumption.

39. A system according to claim 37 wherein said prime mover is the engine of an engine-driven vehicle.

40. A system according to claim 39 wherein said engine is an internal combustion engine.

41. A system according to claim 40 wherein said fuel function is the ideal operating line for minimum fuel consumption.

42. A system according to claim 37 or 40 wherein said fuel function defines desired fuel requirements for the low power range as a function of prime mover operating speed and measured fuel flow.

43. A system according to claim 42 wherein said fuel function for the low power range is given by

44. A system according to claim 37 or 40 wherein said fuel function prescribes for the low power range that the prime mover operate substantially at constant speed.

45. A system according to claim 44 where said fuel function prescribes for the low power range that the prime mover operate substantially at the no-load idle speed thereof.

46. A system according to claim 45 wherein said fuel function defines for the low power range a rate of change of fuel flow and is given by

47. A system according to claim 37 or 40 wherein said fuel function prescribes for the low power range that the prime mover operate at or below the no-load idle speed thereof.

48. A system according to claim 47 wherein said fuel function for the low power range is given by

49. A method of controlling the partial low power operation of a power delivery system including a prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, a continuously variable ratio transmission, and variably engageable coupling means for variably coupling and delivering power from the power delivery system to an output shaft, the partial low power operation occurring when the coupling means is less than fully engaged, the method comprising the steps of:

measuring the speed of the prime mover;

predetermining a fuel function defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed;

controlling the fuel delivery means only in accordance with said fuel function, whereby the speed of the prime mover is regulated in accordance with the load placed thereon; and

commanding desired performance of the power delivery system by varying the degree of engagement of the coupling means.

50. A method according to claim 49 wherein the step of commanding desired performance includes maintaining the transmission at a substantially constant high reduction ratio.

51. A method according to claim 49 wherein said fuel function is the ideal operating line for minimum fuel consumption.

52. A method according to claim 49 wherein the prime mover is the engine of an engine-driven vehicle.

53. A method according to claim 52 wherein the engine is an internal combustion engine.

54. A method according to claim 53 wherein the step of commanding desired performance includes maintaining the transmission at a substantially constant high reduction ratio.

55. A method according to claim 53 wherein said fuel function is the ideal operating line for minimum fuel consumption.

56. A method according to claim 49 or 53 wherein said fuel function defines desired fuel requirements as a function of prime mover operating speed and measured fuel flow.

57. A method according to claim 56 wherein said fuel function is given by

58. A method according to claim 49 or 53 wherein said fuel function prescribes that the prime mover operate substantially at constant speed.

59. A method according to claim 58 where said fuel function prescribes that the prime mover operate substantially at the no-load idle speed thereof.

60. A method according to claim 59 wherein said fuel function defines a rate of change of fuel flow and is given by

61. A method according to claim 49 or 53 wherein said fuel function prescribes that the prime mover operate at or below the no-load idle speed thereof.

62. A method according to claim 61 wherein said fuel function is given by

63. A method of controlling the low power operation of a power delivery system including a prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, a continuously variable ratio transmission, and variably engageable coupling means for variably coupling and delivering power from the power delivery system to an output shaft, the low power operation consisting of a partial power phase during which the coupling means is less than fully engaged, and a full power phase during which the coupling means is fully engaged, the method comprising the steps of:

measuring the speed of the prime mover;

predetermining a fuel function defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed;

controlling the fuel delivery means during both phases of low power operation only in accordance with said fuel function, whereby the speed of the prime mover is regulated in accordance with the load placed thereon;

commanding desired performance of the power delivery system during the partial power phase by varying the degree of engagement of the coupling means; and

commanding desired performance of the power delivery system during the full power phase by reducing the transmission ratio to command an increase in power output and increasing the transmission ratio to command a reduction in power output.

64. A method according to claim 63 wherein the step of commanding desired performance during the partial power phase includes maintaining the transmission at a substantially constant high reduction ratio.

65. A method according to claim 63 wherein said fuel function is the ideal operating line for minimum fuel consumption.

66. A method according to claim 63 wherein the prime mover is the engine of an engine-driven vehicle.

67. A method according to claim 66 wherein the engine is an internal combustion engine.

68. A method according to claim 67 wherein the step of commanding desired performance during the partial power phase includes maintaining the transmission at a substantially constant high reduction ratio.

69. A method according to claim 67 wherein said fuel function is the ideal operating line for minimum fuel consumption.

70. A method according to claim 63 or 67 wherein said fuel function defines desired fuel requirements as a function of prime mover operating speed and measured fuel flow.

71. A method according to claim 70 wherein said fuel function is given by

72. A method according to claim 63 or 67 wherein said fuel function prescribes that the prime mover operate substantially at constant speed.

73. A method according to claim 72 where said fuel function prescribes that the prime mover operate substantially at the no-load idle speed thereof.

74. A method according to claim 73 wherein said fuel function defines a rate of change of fuel flow and is given by

75. A method according to claim 63 or 67 wherein said fuel function prescribes that the prime mover operate at or below the no-load idle speed thereof.

76. A method according to claim 75 wherein said fuel function is given by

77. A system for controlling the partial low power operation of a power delivery system including a prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, a continuously variable ratio transmission, and variably engageable coupling means for variably coupling and delivering power from the power delivery system to an output shaft, the partial low power operation occurring when the coupling means is less than fully engaged, the control system comprising:

speed measuring means for measuring the speed of the prime mover;

fuel function means defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed;

fuel control means operatively coupled to the fuel delivery means and to said speed measuring means and said fuel function means for controlling the fuel delivery means only in accordance with said fuel function, whereby the speed of the prime mover is regulated in accordance with the load placed thereon; and

command means operatively coupled to the coupling means for commanding desired performance of the power delivery system by varying the degree of engagement of the coupling means.

78. A system according to claim 77 wherein said command means is operatively coupled to the transmission and maintains the transmission at a substantially constant high reduction ratio.

79. A system according to claim 77 wherein said fuel function is the ideal operating line for minimum fuel consumption.

80. A system according to claim 77 wherein the prime mover is the engine of an engine-driven vehicle.

81. A system according to claim 80 wherein the engine is an internal combustion engine.

82. A system according to claim 81 wherein said command means is operatively coupled to the transmission and maintains the transmission at a substantially constant high reduction ratio.

83. A system according to claim 81 wherein said fuel function is the ideal operating line for minimum fuel consumption.

84. A system according to claim 77 or 81 wherein said fuel function defines desired fuel requirements as a function of prime mover operating speed and measured fuel flow.

85. A system according to claim 84 wherein said fuel function is given by

86. A system according to claim 77 or 81 wherein said fuel function prescribes that the prime mover operate substantially at constant speed.

87. A system according to claim 86 where said fuel function prescribes that the prime mover operate substantially at the no-load idle speed thereof.

88. A system according to claim 87 wherein said fuel function defines a rate of change of fuel flow and is given by

89. A system according to claim 77 or 81 wherein said fuel function prescribes that the prime mover operate at or below the no-load idle speed thereof.

90. A system according to claim 89 wherein said fuel function is given by

91. A system for controlling the low power operation of a power delivery system including a prime mover having fuel delivery means for delivering a variable quantity of fuel thereto, a continuously variable ratio transmission, and variably engageable coupling means for variably coupling and delivering power from the power delivery system to an output shaft, the low power operation consisting of a partial power phase during which the coupling means is less than fully engaged, and a full power phase during which the coupling means is fully engaged, the control system comprising:

speed measuring means for measuring the speed of the prime mover;

fuel function means defining desired fuel requirements for the prime mover in relation to at least prime mover operating speed, said fuel function prescribing an increased fuel flow for a decrease in measured operating speed and a reduced fuel flow for an increase in measured operating speed;

fuel control means operatively coupled to the fuel delivery means and to said speed measuring means and said fuel function means for controlling the fuel delivery means only in accordance with said fuel function, whereby the speed of the prime mover is regulated in accordance with the load placed thereon; and

command means operatively coupled to the transmission and the coupling means for commanding desired performance of the power delivery system by;

(a) during the partial power phase, varying the degree of engagement of the coupling means; and

(b) during the full power phase, reducing the transmission ratio to increase power output and increasing the transmission ratio to reduce power output.

92. A system according to claim 91 wherein said command means maintains the transmission at a substantially constant high reduction ratio during the partial power phase.

93. A system according to claim 91 wherein said fuel function is the ideal operating line for minimum fuel consumption.

94. A system according to claim 91 wherein the prime mover is the engine of an engine-driven vehicle.

95. A system according to claim 94 wherein the engine is an internal combustion engine.

96. A system according to claim 95 wherein said command means maintains the transmission at a substantially constant high reduction ratio during the partial power phase.

97. A system according to claim 95 wherein said fuel function is the ideal operating line for minimum fuel consumption.

98. A system according to claim 91 or 95 wherein said fuel function defines desired fuel requirements as a function of prime mover operating speed and measured fuel flow.

99. A system according to claim 98 wherein said fuel function is given by

100. A system according to claim 91 or 95 wherein said fuel function prescribes that the prime mover operate substantially at constant speed.

101. A system according to claim 100 where said fuel function prescribes that the prime mover operate substantially at the no-load idle speed thereof.

102. A system according to claim 101 wherein said fuel function defines a rate of change of fuel flow and is given by

103. A system according to claim 91 or 95 wherein said fuel function prescribes that the prime mover operate at or below the no-load idle speed thereof.

104. A system according to claim 103 wherein said fuel function is given by