Shift control system for continuously variable transmission

• US 20010044358A1
• Filed: 05/07/2001
• Published: 11/22/2001
• Est. Priority Date: 05/19/2000
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Mitani, Shinichi, Yamamoto, Yoshiaki, Inoue, Daisuke, Tamura, Tadashi, Mashiki, Zenichiro, Kubota, Hirofumi, Matsuo, Kenji, Kondo, Hiroki, Takagi, Isao, Taniguchi, Hiroji, Yasue, Hideki, Kono, Katsumi, Tanaka, Hiroya
• Granted Patent: US 6,450,917 B2
• Time in Patent Office: Days
• US Class Current: 477/44
• CPC Class Codes: F16H 2061/6611 Control to achieve a particular driver perception, e.g. for generating a shift shock sensation
• CPC Class Codes: F16H 61/66254 controlling of shifting being influenced by a signal derived from the engine and the main coupling
• CPC Class Codes: F16H 61/6648 controlling of shifting being influenced by a signal derived from the engine and the main coupling

Abstract

A speed change control system for a continuously variable transmission, for controlling a gear ratio by deciding an abrupt acceleration demand of a driver, to effect an abrupt speed change when it is decided that the driver demands an abrupt acceleration. The speed change control system comprises: a drive state decider for deciding that the vehicle has changed from a driven state to a drive state, when said abrupt acceleration is demanded at the driven state; and a speed change controller for controlling said continuously variable transmission to effect said abrupt speed change, after said drive state decider decides that the vehicle has changed from the driven state to the drive state.

Claims

1. A speed change control system for a continuously variable transmission, for controlling a gear ratio to effect an abrupt speed change when it is decided that a driver demands an abrupt acceleration, comprising:

drive state deciding means for deciding that the vehicle has changed from a driven state to a drive state, in response to the demand of said abrupt acceleration when the vehicle is in the driven state; and

speed change control means for controlling said continuously variable transmission to effect said abrupt speed change, after said drive state deciding means decides that the vehicle has changed from the driven state to the drive state.

2. A speed change control system according to

claim 1

,

wherein said speed change control means includes means for controlling the continuously variable transmission to interrupt a speed change for a time period from the decision of said abrupt acceleration demand to the change of the vehicle to the drive state, when said abrupt acceleration is demanded at the driven state of the vehicle.

3. A speed change control system according to

claim 1

,

wherein said speed change control means includes means for controlling the continuously variable transmission to perform the abrupt speed change when said abrupt acceleration demand is decided, when said abrupt acceleration is demanded at the drive state of the vehicle.

4. A speed change control system according to

claim 1

,

wherein said speed change control means includes means for controlling the gear ratio of the continuously variable transmission so that an input speed may be a target input speed set on the basis of a running state of the vehicle, and for making an increase amount of the target input speed larger than an increase amount at a speed change other than the abrupt speed change when the abrupt speed change is to be performed.

5. A speed change control system according to

claim 3

,

wherein said speed change control means includes means for controlling the gear ratio of the continuously variable transmission so that an input speed may be a target input speed set on the basis of a running state of the vehicle, and for making an increase amount of the target input speed larger than an increase amount at a speed change other than the abrupt speed change when the abrupt speed change is to be performed.

6. A speed change control system according to

claim 1

, further comprising:

output control means for executing a rounding control to relax an increase of an output of a prime mover mounted on the vehicle, when the abrupt acceleration is demanded.

7. A speed change control system according to

claim 1

,

wherein said speed change control means includes means for controlling the continuously variable transmission to lower a speed changing rate to a value as low as zero for a time period from the decision of said abrupt acceleration demand to the change of the vehicle to the drive state, when said abrupt acceleration is demanded at the driven state of the vehicle.

8. A speed change control system according to

claim 1

, further comprising:

means for deciding that the abrupt acceleration is demanded, on the basis of a changing rate of an accelerator depression.

9. A speed change control system according to

claim 1

,

wherein said drive state deciding means includes means for deciding that the vehicle has changed from the driven state to the drive state, on the basis of a lapse time period from an instant when a prime mover mounted on the vehicle changes from an idling state to a non-idling state.

10. A speed change control system according to

claim 1

,

wherein said drive state deciding means includes:

means for estimating a driving force of the vehicle; and

means for deciding that the vehicle has changed to the drive state, when the estimated driving force is higher than a road load.

11. A speed change control system for a continuously variable transmission, for controlling a gear ratio to effect an abrupt speed change when it is decided that a driver demands an abrupt acceleration, comprising:

a controller for deciding that the vehicle has changed from a driven state to a drive state in response to the demand of said abrupt acceleration when the vehicle is in the driven state; and

for controlling said continuously variable transmission to effect said abrupt speed change after said drive state deciding means decides that the vehicle has changed from the driven state to the drive state.

12. A speed change control system according to

claim 11

,

wherein said controller includes a judging device for judging that the vehicle has changed from a driven state to a drive state in response to the demand of said abrupt acceleration when the vehicle is in the driven state;

and a shift controller for controlling said continuously variable transmission to effect said abrupt speed change after said judging device judges that the vehicle has changed from the driven state to the drive state.

13. A speed change control system according to

claim 12

,

wherein said shift controller includes a device for controlling the continuously variable transmission to interrupt a speed change for a time period from the judge of said abrupt acceleration demand to the change of the vehicle to the drive state, when said abrupt acceleration is demanded at the driven state of the vehicle.

14. A speed change control system according to

claim 12

,

wherein said shift controller includes a device for controlling the continuously variable transmission to perform the abrupt speed change when said abrupt acceleration demand is judged, when said abrupt acceleration is demanded at the drive state of the vehicle.

15. A speed change control system according to

claim 12

,

wherein said shift controller includes a device for controlling the gear ratio of the continuously variable transmission so that an input speed may be a target input speed set on the basis of a running state of the vehicle, and for making an increase amount of the target input speed larger than an increase amount at a speed change other than the abrupt speed change when the abrupt speed change is to be performed.

16. A speed change control system according to

claim 14

,

wherein said shift controller includes a device for controlling the gear ratio of the continuously variable transmission so that an input speed may be a target input speed set on the basis of a running state of the vehicle, and for making an increase amount of the target input speed larger than an increase amount at a speed change other than the abrupt speed change when the abrupt speed change is to be performed.

17. A speed change control system according to

claim 12

, further comprising:

output controller for executing a rounding control to relax an increase of an output of a prime mover mounted on the vehicle, when the abrupt acceleration is demanded.

18. A speed change control system according to

claim 12

,

wherein said shift controller includes a device for controlling the continuously variable transmission to lower a speed changing rate to a value as low as zero for a time period from the decision of said abrupt acceleration demand to the change of the vehicle to the drive state, when said abrupt acceleration is demanded at the driven state of the vehicle.

19. A speed change control system according to

claim 12

, further comprising:

a device for deciding that the abrupt acceleration is demanded, on the basis of a changing rate of an accelerator depression.

20. A speed change control system according to

claim 12

,

wherein said judging device includes a device for judging that the vehicle has changed from the driven state to the drive state, on the basis of a lapse time period from an instant when a prime mover mounted on the vehicle changes from an idling state to a non-idling state.

21. A speed change control system according to

claim 12

,

wherein said judging device includes:

a device for estimating a driving force of the vehicle; and

deciding device for deciding that the vehicle has changed to the drive state, when the estimated driving force is higher than a road load.

22. A speed change control method for a continuously variable transmission, for controlling a gear ratio to effect an abrupt speed change when it is decided that a driver demands an abrupt acceleration, comprising:

a step for judging that the vehicle has changed from a driven state to a drive state, in response to the demand of said abrupt acceleration when the vehicle is in the driven state; and

a step for controlling said continuously variable transmission to effect said abrupt speed change, after it is judged that the vehicle has changed from the driven state to the drive state.

23. A speed change control method according to

claim 22

,

wherein said step for controlling said continuously variable transmission includes a step for controlling the continuously variable transmission to interrupt a speed change for a time period from the judge of said abrupt acceleration demand to the change of the vehicle to the drive state, when said abrupt acceleration is demanded at the driven state of the vehicle.

24. A speed change control method according to

claim 22

,

wherein said step for controlling said continuously variable transmission includes a step for controlling the continuously variable transmission to perform the abrupt speed change when said abrupt acceleration demand is decided, when said abrupt acceleration is demanded at the drive state of the vehicle.

25. A speed change control method according to

claim 22

,

wherein said step for controlling said continuously variable transmission includes a step for controlling the gear ratio of the continuously variable transmission so that an input speed may be a target input speed set on the basis of a running state of the vehicle, and for making an increase amount of the target input speed larger than an increase amount at a speed change other than the abrupt speed change when the abrupt speed change is to be performed.

26. A speed change control system according to

claim 24

,

wherein said step for controlling said continuously variable transmission includes a step for controlling the gear ratio of the continuously variable transmission so that an input speed may be a target input speed set on the basis of a running state of the vehicle, and for making an increase amount of the target input speed larger than an increase amount at a speed change other than the abrupt speed change when the abrupt speed change is to be performed.

27. A speed change control method according to

claim 22

, further comprising:

a step for executing a rounding control to relax an increase of an output of a prime mover mounted on the vehicle, when the abrupt acceleration is demanded.

28. A speed change control method according to

claim 22

,

wherein said step for controlling said continuously variable transmission includes a step for controlling the continuously variable transmission to lower a speed changing rate to a value as low as zero for a time period from the decision of said abrupt acceleration demand to the change of the vehicle to the drive state, when said abrupt acceleration is demanded at the driven state of the vehicle.

29. A speed change control method according to

claim 22

, further comprising:

a step for judging that the abrupt acceleration is demanded, on the basis of a changing rate of an accelerator depression.

30. A speed change control method according to

claim 22

,

wherein said step for judging includes a step for judging that the vehicle has changed from the driven state to the drive state, on the basis of a lapse time period from an instant when a prime mover mounted on the vehicle changes from an idling state to a non-idling state.

31. A speed change control method according to

claim 22

,

wherein said step for judging includes:

a step for estimating a driving force of the vehicle; and

a step for deciding that the vehicle has changed to the drive state, when the estimated driving force is higher than a road load.