Vehicle braking control device for braking force distribution

• US 20040260446A1
• Filed: 04/02/2004
• Published: 12/23/2004
• Est. Priority Date: 04/07/2003
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Advics Company Limited (Aisin Corp.), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hamada, Chiaki, Doura, Akifumi
• Granted Patent: US 8,600,637 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60T 8/17616 Microprocessor-based systems
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle
• CPC Class Codes: B60T 8/268 using the valves of an ABS, ASR or ESP system
• CPC Class Codes: B60T 8/4072 Systems in which a driver input signal is used as a control signal for the additional fluid circuit which is normally used for braking
• CPC Class Codes: B60T 8/4872 pump-back systems
• CPC Class Codes: B60T 8/885 using electrical circuitry

Abstract

A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel in a manner compatible with Anti-skid control. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. Upon starting anti-skid control for either of the wheels during the execution of BFD control, an increment of the front wheel braking forces to be requested by BFD control is gradually decreased. Simultaneously, the holding of the rear braking force is released so as to compensate for the shortage of braking force on the front wheel. The gradual decrease of the braking force increment prevents a conflict of BFD and Anti-skid control.

Claims

1. A device for controlling a braking of a vehicle having front and rear wheels, a braking system generating braking forces on the respective wheels, at least one sensor monitoring an operational condition of the vehicle including a detector detecting an amount of a braking action by a driver of the vehicle, and the device executing a braking force distribution control in which braking force on the rear wheels is lowered in comparison with braking force on the front wheels when an operational condition monitored by a sensor among the at least on sensor stratifies a predetermined condition, characterized in that braking force on the front wheels during execution of the braking force distribution control is increased, where a braking force increment on the front wheel beyond braking force corresponding to the braking action is determined based upon an increment of the braking action by the driver detected by the detector;

and when anti-skid control for either of the wheels is executed, the braking force increment on the front wheel is decreased.

2. A device of claim 1, characterized in that braking force on the rear wheels is increased when the anti-skid control is executed.

3. A device of claim 1, characterized in that the braking force increment on the front wheel is decreased until the increment reaches to zero.

4. A device of claim 1, characterized in that the decreasing of the braking force increment on the front wheel is interrupted if the anti-skid control is terminated but the increment does not reach to zero.

5. A device of claim 1, wherein the braking system comprises a hydraulic circuit connected with a master cylinder and braking force generating apparatus including wheel cylinders provided for the respective wheels;

and the braking action is reflected in a pressure in the master cylinder, characterized in that the decreasing of the braking force increment is executed by decreasing braking pressures in the front wheel cylinders.

6. A device of claim 2, wherein the hydraulic circuit comprises a hydraulic circuit connected with a master cylinder and braking force generating apparatus including wheel cylinders provided for the respective wheels;

the braking action is reflected in a pressure in the master cylinder; and

valves selectively allowing fluid communication between the master cylinder and the rear wheel cylinders, characterized in that the increasing of the rear wheel braking force is executed by opening the valves.

7. A device of claim 5, wherein the hydraulic circuit comprises at least a common line applying at least one of the front wheel cylinders and at least one of the rear wheel cylinders, and at least a pressure regulating valve in the common line regulating a pressure in the common line and selectively fluidly connecting the common line to master cylinder.

8. A device of claim 7, wherein the hydraulic circuit is of cross dual circuit type.

9. A device of claim 7, wherein the hydraulic circuit is of front-rear dual circuit type.

10. A device of claim 7, wherein the hydraulic circuit comprises valves selectively allowing fluid communication between the common line and the rear wheel cylinders, characterized in that the increasing of the rear wheel braking force is executed by opening the valves.

11. A device of claim 6, wherein the opening of the valves is executed intermittently.

12. A device for controlling a braking of a vehicle having front and rear wheels, a braking system generating braking forces on the respective wheels, at least one sensor monitoring an operational condition of the vehicle including a detector detecting an amount of a braking action by a driver of the vehicle, the device executing a braking force distribution control in which braking force on the rear wheels is lowered in comparison with braking force on the front wheels when an operational condition monitored by a sensor among the at least one sensor stratifies a predetermined condition for starting the braking force distribution control, characterized in that braking force on the front wheels during execution of the braking force distribution control is increased during execution of the braking force distribution control, but decreased when anti-skid control for either of the wheels is executed or when an operational condition monitored by the sensor stratifies, a predetermined condition for terminating the braking force distribution control.

13. A device of claim 12, wherein a rate of decreasing the front wheel braking force when an operational condition monitored by a sensor among the at least one sensor stratifies a predetermined condition for terminating the braking force distribution control is faster than a rate of decreasing the front wheel braking force when anti-skid control for either of the wheels is executed.

14. A device of claim 12, wherein the braking force on the front wheel is decreased until the braking force reaches to braking force requested by the braking action by the driver.

15. A device of claim 12, wherein the increase of the braking force on the rear wheels is restricted during execution of the braking force distribution control but allowed when anti-skid control for either of the wheels is executed or when an operational condition monitored by a sensor among the at least one sensor stratifies a predetermined condition for terminating the braking force distribution control.