Wheel Control Device and Control Device

• US 20080162009A1
• Filed: 12/27/2005
• Published: 07/03/2008
• Est. Priority Date: 12/27/2004
• Status: Active Grant

• Current Assignee: Equos Research Co., Ltd. (Aisin Corp.)
• Original Assignee: Kabushikikaisha Equos Research
• Inventors: Miyake, Takafumi, Miki, Nobuaki, Horiguchi, Munehisa, Okawa, Susumu
• Granted Patent: US 7,991,532 B2
• Time in Patent Office: Days
• US Class Current: 701/80
• CPC Class Codes: B60G 17/0164 mainly during accelerating or braking
• CPC Class Codes: B60G 2200/46 camber angle
• CPC Class Codes: B60G 2200/462 Toe-in/out
• CPC Class Codes: B60G 2202/413 Hydraulic actuator
• CPC Class Codes: B60G 2204/182 Electric motor on wheel support
• CPC Class Codes: B60G 2400/39 Brake pedal position
• CPC Class Codes: B60G 7/006 Attaching arms to sprung or unsprung part of vehicle, characterised by comprising attachment means controlled by an external actuator, e.g. a fluid or electrical motor B62D7/146 takes precedence
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/00 Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• CPC Class Codes: B62D 9/007 Emergency systems using the steering system for braking

Abstract

The present invention provides a novel method for generating braking force in a wheel. In a vehicle having wheels, a wheel control device for controlling the wheels is provided with an actuator for performing an operation to vary a slip angle of the wheels, and a controller for controlling the actuator to increase the braking force of the wheels by increasing the slip angle absolute value of the wheels such that a lateral force is generated in the wheels relative to a ground contact surface of the wheels.

Claims

1. A wheel control device for controlling a wheel in a vehicle having said wheel, comprising:

an actuator that operates to vary a slip angle of said wheel; and

a controller for controlling said actuator to increase a braking force of said wheel by increasing said slip angle absolute value of said wheel such that a lateral force is generated in said wheel relative to a ground contact surface of said wheel,

wherein said controller comprises a braking control portion for controlling said actuator to apply braking to said vehicle, and

when braking of said vehicle is required, said braking control portion performs at least one of increasing said slip angle absolute value by a fixed amount and varying said slip angle absolute value by any amount.

2. The wheel control device according to claim 1, wherein, when braking of said vehicle is required, said braking control portion increases said slip angle absolute value by a variable amount based on at least one of a frictional coefficient of a part of a road surface along which said vehicle is traveling that is contacted by said wheel, and a ground contact load of said wheel.

17. The wheel control device according to claim 1, wherein said controller comprises an emergency braking control portion for controlling said actuator to apply emergency braking to said vehicle, and

when emergency braking of said vehicle is required, said emergency braking control portion performs at least one of increasing said slip angle absolute value by a fixed amount and increasing said slip angle absolute value by a variable amount corresponding to a required deceleration of said vehicle.

18. The wheel control device according to claim 1, wherein said vehicle further comprises a power source for driving said wheel, and

said controller comprises a driving control portion for controlling said actuator when said vehicle needs to be driven by said power source to reduce a driving torque of said wheel, generated by said drive source, using said braking force of said wheel.

19. The wheel control device according to claim 2, wherein said vehicle further comprises a power source for driving said wheel, and

said controller comprises a driving control portion for controlling said actuator when said vehicle needs to be driven by said power source to reduce a driving torque of said wheel, generated by said drive source, using said braking force of said wheel.

3. The wheel control device according to claim Or 2, wherein said controller comprises an emergency braking control portion for controlling said actuator to apply emergency braking to said vehicle, and

when emergency braking of said vehicle is required, said emergency braking control portion performs at least one of increasing said slip angle absolute value by a fixed amount and increasing said slip angle absolute value by a variable amount corresponding to a required deceleration of said vehicle.

4. The wheel control device according to claim 3, wherein said vehicle further comprises a power source for driving said wheel, and

said controller comprises a driving control portion for controlling said actuator when said vehicle needs to be driven by said power source to reduce a driving torque of said wheel, generated by said drive source, using said braking force of said wheel.

5. A control device for a vehicle having a wheel constituted to be steerable, an actuator device for steerably driving said wheel, and a wheel driving device for driving said wheel to rotate, which operates said actuator device and said wheel driving device to control a slip angle and a rotation speed of said wheel, and comprises:

an actuator operating unit for operating said actuator device to increase a braking force of said wheel by increasing a slip angle absolute value of said wheel such that a lateral force is generated on a ground contact surface of said wheel; and

a wheel driving device operating unit for operating said wheel driving device to vary said rotation speed of said wheel, said slip angle absolute value of which has been increased by said actuator operating unit, such that an amount of vehicle advancement direction deformation on said ground contact surface of said wheel increases.

6. The control device according to claim 5, further comprising:

a ground speed detecting unit for detecting a ground speed of said vehicle;

a rotation speed detecting unit for detecting said rotation speed of said wheel;

a slip angle detecting unit for detecting said slip angle of said wheel;

a deformation amount calculating unit for calculating said amount of vehicle advancement direction deformation on said ground contact surface of said wheel on the basis of said ground speed, said rotation speed, and said slip angle detected by said ground speed detecting unit, said rotation speed detecting unit, and said slip angle detecting unit; and

a storage unit for storing a limit value of said vehicle advancement direction deformation on said ground contact surface of said wheel,

wherein said wheel driving device operating unit operates said wheel driving device to vary said rotation speed of said wheel such that said amount of vehicle advancement direction deformation on said ground contact surface of said wheel increases within a range that does not exceed said deformation limit value stored in said storage unit.

7. The control device according to claim 6, further comprising:

a frictional coefficient detecting unit for detecting a frictional coefficient of a part of a road surface along which said wheel is traveling that corresponds to said ground contact surface of said wheel; and

a correcting unit for correcting said deformation limit value stored in said storage unit on the basis of said frictional coefficient detected by said frictional coefficient detecting unit,

wherein said wheel driving device operating unit operates said wheel driving device to vary said rotation speed of said wheel such that said amount of vehicle advancement direction deformation on said ground contact surface of said wheel increases within a range that does not exceed said deformation limit value corrected by said correcting unit.

8. The control device according to claim 7, wherein said wheel comprises a left wheel and a right wheel disposed on left and right sides of said vehicle, and

said actuator operating unit operates said actuator device such that said left wheel and said right wheel have a toe-in relationship when said slip angle absolute value of at least one of said left wheel and said right wheel is increased to increase said braking force of at least one of said left wheel and said right wheel.

9. The control device according to claim 8, wherein said actuator operating unit operates said actuator device such that said slip angle absolute value of said left wheel and said slip angle absolute value of said right wheel are identical.

20. The control device according to claim 5, wherein said wheel comprises a left wheel and a right wheel disposed on left and right sides of said vehicle, and

said actuator operating unit operates said actuator device such that said left wheel and said right wheel have a toe-in relationship when said slip angle absolute value of at least one of said left wheel and said right wheel is increased to increase said braking force of at least one of said left wheel and said right wheel.

21. The control device according to claim 20, wherein said actuator operating unit operates said actuator device such that said slip angle absolute value of said left wheel and said slip angle absolute value of said right wheel are identical.

10. A control device for a vehicle having left and right wheels and an actuator device for adjusting a camber angle of said left and right wheels, which operates said actuator device to control said camber angle of said left and right wheels, and comprises:

a braking instruction determining unit for determining whether or not a braking instruction for braking said vehicle has been issued; and

an actuator device operating unit for operating said actuator device to increase an absolute value of said camber angle of said left and right wheels when said braking instruction determining unit determines that a braking instruction has been issued.

11. The control device according to claim 10, wherein said left and right wheels are constituted to be steerable, and said actuator device is constituted to be capable of adjusting a steering angle of said left and right wheels, and

said actuator device operating unit operates said actuator device to increase an absolute value of said steering angle of said left and right wheels and such that said left and right wheels become toe-in or toe-out when said braking instruction determining unit determines that a braking instruction has been issued.

12. The control device according to claim 11, further comprising:

a frictional coefficient detecting unit for detecting a frictional coefficient of a part of a road surface along which said left and right wheels are traveling that corresponds to a ground contact surface of said left and right wheels;

a ground contact load detecting unit for detecting a ground contact load on said ground contact surface of said left and right wheels;

a coefficient calculating unit for calculating a coefficient obtained by multiplying said frictional coefficient detected by said frictional coefficient detecting unit by said ground contact load detected by said ground contact load detecting unit; and

an angle correcting unit for correcting an absolute value of said camber angle and said steering angle of said left and right wheels on the basis of said coefficient calculated by said coefficient calculating unit,

wherein said angle correcting unit corrects said absolute value of said camber angle and said steering angle such that said absolute value of at least one of, or both of, said camber angle and said steering angle of a wheel having a smaller coefficient becomes larger than said absolute value of said camber angle or said steering angle of a wheel having a larger coefficient.

13. The control device according to claim 12, wherein said vehicle comprises an operating member that is operated by a driver, and a brake device for applying a braking force to said left and right wheels in conjunction with an operation state of said operating member,

said braking instruction determining unit determines that a braking instruction has been issued when said operating member is operated or when an operation of said operating member satisfies a predetermined condition, and

when said braking instruction determining unit determines that a braking instruction has been issued, said actuator device operating unit operates said actuator device and said brake device applies said braking force to said left and right wheels.

22. The control device according to claim 10, wherein said vehicle comprises an operating member that is operated by a driver, and a brake device for applying a braking force to said left and right wheels in conjunction with an operation state of said operating member,

said braking instruction determining unit determines that a braking instruction has been issued when said operating member is operated or when an operation of said operating member satisfies a predetermined condition, and

when said braking instruction determining unit determines that a braking instruction has been issued, said actuator device operating unit operates said actuator device and said brake device applies said braking force to said left and right wheels.

14. A wheel control device for a vehicle having front/rear left/right steered wheels and a power source, which controls a slip angle of said steered wheels and comprises:

an actuator device for performing an operation to vary respective slip angles of a left wheel and a right wheel of said steered wheels; and

a controller for controlling said actuator device during driving of said steered wheels by said power source such that said respective slip angles of said left wheel and said right wheel of said steered wheels vary by identical amounts at a time in a direction for increasing respective toe-in tendencies of said left wheel and said right wheel,

wherein said controller comprises a first control portion for varying said respective slip angles of said left wheel and said right wheel of said steered wheels by identical amounts at a time and by a variable amount based on at least one of a frictional coefficient of a part of a road surface along which said vehicle is traveling that is contacted by a corresponding wheel, and a ground contact load of said corresponding wheel.

15. The wheel control device according to claim 14, wherein said controller further comprises a second control portion for performing at least one of varying said respective slip angles of said left wheel and said right wheel of said steered wheels by identical amounts at a time and by a fixed amount, and varying said respective slip angles of said left wheel and said right wheel of said steered wheels by identical amounts at a time and by a variable amount based on a required acceleration of said vehicle.

16. The wheel control device according to claim 14, wherein said controller further comprises a third control portion for varying said respective slip angles of said left wheel and said right wheel of said steered wheels by identical amounts at a time in a direction for increasing said respective toe-in tendencies of said left wheel and said right wheel in a case where a spin tendency of said steered wheels may depart from an allowable range when said power source is operated in accordance with an operation performed by said driver to instruct start-up of said vehicle through said power source.