TRACTION CONTROL SYSTEM FOR VEHICLE

• US 20100298092A1
• Filed: 02/27/2009
• Published: 11/25/2010
• Est. Priority Date: 03/03/2008
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tsuchikawa, Haruhisa
• Granted Patent: US 8,206,263 B2
• Time in Patent Office: Days
• US Class Current: 477/71
• CPC Class Codes: B60K 28/165 acting on elements of the vehicle drive train other than the propulsion unit and brakes, e.g. transmission, clutch, differential acting on brakes B60T8/17
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 7/14 for vehicles propelled by ac motors
• CPC Class Codes: B60T 2260/04 Automatic transmission
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0291 : Clutch temperature
• CPC Class Codes: B60W 2510/0638 : Engine speed
• CPC Class Codes: B60W 2510/0676 : Engine temperature
• CPC Class Codes: B60W 2510/081 : Speed
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: B60W 2540/10 : Accelerator pedal position
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 30/18172 : Preventing, or responsive to skidding of wheels
• CPC Class Codes: F02D 29/02 : peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/0215 : in relation with elements of the transmission
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

In order to attain a stable traction control regardless of an inertia change in a driving system, when a driving force transmitted from driving wheels to a road surface is lowered by a certain quantity by torque control, the driving force is lowered according to a transmission torque capacity of a clutch element for connecting and disconnecting a power source and the driving wheels

Claims

1. A traction control system for driving wheels of a vehicle, comprising:

a power source;

a starting clutch having a variable transmission torque capacity and interposed between the power source and the driving wheels to connect and disconnect the power source and the driving wheels;

a braking device associated with each of the driving wheels and capable of independently controlling a braking force to each wheel; and

a controller configured to lower a driving force transmitted from the driving wheels to a road surface by controlling a driving torque of the power source and/or a braking force to the driving wheels when an acceleration slip in the driving wheels is above a certain value and further configured to reduce a lowering quantity of the driving force as the variable transmission torque capacity of the starting clutch decreases.

2. The traction control system as in claim 1 wherein the controller is further configured to further reduce the lowering quantity of the driving force when the starting clutch is slip-engaged below that at a time when the starting clutch is completely engaged.

3. The traction control system as in claim 1 wherein

the power source includes an engine and a motor disposed at a power output side of the engine;

the traction control system includes an engine clutch for connecting and disconnecting the engine and the motor;

the starting clutch is interposed between the motor and the driving wheels; and

the controller is further configured to set the lowering quantity of the driving force according to the variable transmission torque capacity of the starting clutch and a transmission torque capacity of the engine clutch.

4. The traction control system as in claim 3 wherein the controller is further configured to increase the lowering quantity of the driving force when the starting clutch is engaged while the engine clutch is engaged above that at a time when the engine clutch is disengaged.

5. The traction control system as in claim 3 wherein the controller is further configured to set the lowering quantity of the driving force regardless of the transmission torque capacity of the engine clutch when the starting clutch is slip-engaged.

6. The traction control system as in claim 1, further comprising:

a geared automatic transmission interposed between the power source and the driving wheels; and

wherein

the controller is further configured to set the lowering quantity of the driving force according to an inertia at each gear-stage of the geared automatic transmission.

7. The traction control system as in claim 1 wherein the controller is further configured to lower the driving force transmitted from the driving wheels to the road surface by making a command to plural actuators and to output to the plural actuators a command for synchronizing an operation of an actuator that is the slowest in response speed of the plural actuators with operations of the other actuators.

8. The traction control system as in claim 1 wherein the controller is further configured to lower the driving force transmitted from the driving wheels to the road surface by controlling the braking force of the driving wheels when the starting clutch is slip-engaged.

9. The traction control system as in claim 1, further comprising:

an acceleration slip quantity detecting part for detecting or estimating an acceleration slip in the driving wheels.

10. A traction control system controller for driving wheels of a vehicle comprising a power source, a starting clutch having a variable transmission torque capacity and interposed between the power source and the driving wheels to connect and disconnect the power source and the driving wheels, a braking device associated with each of the driving wheels and capable of independently controlling a braking force to each wheel, the controller comprising:

means for lowering a driving force transmitted from the driving wheels to a road surface by controlling a driving torque of the power source and/or a braking force to the driving wheels when an acceleration slip of the driving wheels is above a certain value; and

means for reducing a lowering quantity of the driving force as the variable transmission torque capacity of the starting clutch decreases.

11. A method of controlling a traction control system for driving wheels of a vehicle comprising a power source, a starting clutch having a variable transmission torque capacity and interposed between the power source and the driving wheels to connect and disconnect the power source and the driving wheels, a braking device associated with each of the driving wheels and capable of independently controlling a braking force to each wheel, the method comprising:

lowering a driving force transmitted from the driving wheels to a road surface by controlling a driving torque of the power source and/or a braking force to the driving wheels when an acceleration slip of the driving wheels is above a certain value; and

reducing a lowering quantity of the driving force as the variable transmission torque capacity of the starting clutch decreases.

12. The method as in claim 11, further comprising:

further reducing the lowering quantity of the driving force when the starting clutch is slip-engaged below that at a time when the starting clutch is completely engaged.

13. The method as in claim 11 wherein the power source includes an engine and a motor disposed at a power output side of the engine, the traction control system includes an engine clutch for connecting and disconnecting the engine and the motor, and the starting clutch is interposed between the motor and the driving wheels, further comprising:

setting the lowering quantity of the driving force according to the variable transmission torque capacity of the starting clutch and a transmission torque capacity of the engine clutch.

14. The method as in claim 13, further comprising:

increasing the lowering quantity of the driving force when the starting clutch is engaged while the engine clutch is engaged above that at a time when the engine clutch is disengaged.

15. The method as in claim 13, further comprising:

setting the lowering quantity of the driving force regardless of the transmission torque capacity of the engine clutch when the starting clutch is slip-engaged.

16. The method as in claim 11 wherein a geared automatic transmission is interposed between the power source and the driving wheels, the method further comprising:

setting the lowering quantity of the driving force according to an inertia at each gear-stage of the geared automatic transmission.

17. The method as in claim 11, further comprising:

lowering the driving force transmitted from the driving wheels to the road surface by making a command to plural actuators; and

outputting to the plural actuators a command for synchronizing an operation of an actuator that is the slowest in response speed of the plural actuators with operations of the other actuators.

18. The method as in claim 11, further comprising:

lowering the driving force transmitted from the driving wheels to the road surface by controlling the braking force of the driving wheels when the starting clutch is slip-engaged.