Control system for vehicle having continuously variable transmission

• US 6,440,037 B2
• Filed: 03/07/2001
• Issued: 08/27/2002
• Est. Priority Date: 03/10/2000
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kubota, Hirofumi, Takagi, Isao
• Primary Examiner(s): Butler, Douglas C.
• Application Number:
  US09/799,563
• Publication Number:
  US 20010021683A1
• Time in Patent Office: 538 Days
• Field of Search: 477/37, 477/107, 477/43, 477/39, 477/48, 477/111, 477/44, 477/49, 477/109, 477/98, 477/906, 477/46, 477/110, 477/174, 477/173, 701/54, 701/58, 701/60, 701/51, 701/111, 701/103, 701/101, 701/110, 123/295, 123/319, 123/339.1, 123/339.14, 123/339.18, 123/339.17, 180/197
• US Class Current: 477/37
• 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 10/11 Stepped gearings
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/188 Controlling power parameters of the driveline, e.g. determining the required power
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38

Abstract

A control system for a vehicle including a continuously variable is constructed: such that a target output of a prime mover for achieving a target driving force is determined on the basis of the target driving force; such that a target output speed is determined on the basis of the target output; such that a gear ratio of the continuously variable transmission is controlled so that an output speed of the prime mover may be the target output speed; such that a target output torque of the prime mover for achieving the target driving force is determined on the basis of the target driving force; and such that a load of the prime mover is controlled on the basis of the target output torque. The control system further comprises a corrector for correcting a control quantity to control the load of the prime mover so that the output torque of the prime mover may have the sum of the target output torque and an output torque for keeping the idle run of the prime mover.

Claims

1. A control system for a vehicle provided with a continuously variable transmission, which has target output calculating means for determining a target output of a prime mover for achieving a target driving force, on the basis of said target driving force;

target output speed calculating means for determining a target output speed on the basis of said target output;

gear ratio control means for controlling a gear ratio of said continuously variable transmission so that an output speed of said prime mover may be said target output speed;

target output torque calculating means for determining a target output torque of said prime mover for achieving said target driving force, on the basis of said target driving force; and

load control means for controlling a load of said prime mover on the basis of said target output torque, comprising;

correction means for correcting a control quantity to control the load of said prime mover so that the output torque of said prime mover may have a sum of said target output torque and an output torque for keeping the idle run of said prime mover.

2. A control system according to claim 1,

wherein said correction means includes means for determining a corrected output torque for keeping the idle run of said prime mover and correcting said target output torque on the basis of said corrected output torque.

3. A control system according to claim 2, further comprising:

target speed correction means for correcting said target output speed on the basis of an accessory load.

4. A control system according to claim 3,

wherein said target speed correction means includes means for determining an accessory load output for said accessory load and correcting said target output speed on the basis of said accessory load output.

5. A control system according to claim 1,

wherein said correction means includes means for determining a corrected output for keeping the idle run of said prime mover and correcting said target output on the basis of said corrected output.

6. A control system according to claim 1,

wherein said correction means includes means for determining a corrected driving force for keeping the idle run of said prime mover and correcting said target driving force on the basis of said corrected driving force.

7. A control system according to claim 1,

wherein said correction means includes means for changing a corrected value for correcting said control quantity into a smaller value when said corrected value exceeds a predetermined value during the running of the vehicle.

8. A control system according to claim 2,

wherein said correction means includes means for changing a corrected value for correcting said control quantity into a smaller value when said corrected value exceeds a predetermined value during the running of the vehicle.

9. A control system according to claim 3,

wherein said correction means includes means for changing a corrected value for correcting said control quantity into a smaller value when said corrected value exceeds a predetermined value during the running of the vehicle.

10. A control system according to claim 4,

wherein said correction means includes means for changing a corrected value for correcting said control quantity into a smaller value when said corrected value exceeds a predetermined value during the running of the vehicle.

11. A control system according to claim 5,

wherein said correction means includes means for changing a corrected value for correcting said control quantity into a smaller value when said corrected value exceeds a predetermined value during the running of the vehicle.

12. A control system according to claim 6,

wherein said correction means includes means for changing a corrected value for correcting said control quantity into a smaller value when said corrected value exceeds a predetermined value during the running of the vehicle.