Vehicular brake control apparatus and vehicular brake control method

• US 6,443,540 B2
• Filed: 01/19/2001
• Issued: 09/03/2002
• Est. Priority Date: 02/14/2000
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Shimizu, Satoshi, Tsuchiya, Yoshiaki
• Primary Examiner(s): Lavinder, Jack
• Assistant Examiner(s): Pezzlo, Benjamin A
• Application Number:
  US09/764,155
• Publication Number:
  US 20010013724A1
• Time in Patent Office: 592 Days
• Field of Search: 303/9.62, 303/177, 303/116.2
• US Class Current: 303/177
• CPC Class Codes: B60T 2220/04 Pedal travel sensor, stroke sensor; Sensing brake request
• 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 8/266 using valves or actuators with external control means B60T8/261 takes precedence

Abstract

A vehicular brake control apparatus performs braking force limiting control for limiting, if the vehicle is in a predetermined driving state, braking forces applied to rear wheels of the vehicle in comparison with the braking forces applied to the front wheels. If it is judged during the braking force limiting control that the amount of braking operation by the driver has increased, the apparatus increases the braking forces applied to the rear wheels.

Claims

1. A vehicular brake control apparatus, comprising:

a brake controller that;

determines a brake operating amount by a driver;

limits braking forces applied to rear wheels of the vehicle in comparison with braking forces applied to front wheels when the vehicle is in a predetermined driving state;

incorporates a value of a parameter, that changes according to the brake operating amount, into a threshold value for determining whether the braking forces applied to the rear wheels is increased during the braking force limiting; and

increases the braking forces applied to the rear wheels, if the value of the parameter is larger than the incorporated threshold value during the braking force limiting.

2. The apparatus according to claim 1, wherein

the brake controller determines that the vehicle is in the predetermined driving state when the deceleration of the vehicle is equal to or higher than a threshold value, and performs the braking force limiting.

3. The apparatus according to claim 1, wherein

the parameter is the deceleration of the vehicle, and

the brake controller determines that the brake operating amount by the driver has increased by determining that the deceleration of the vehicle has increased.

4. The apparatus according to claim 1, wherein

the parameter is a stroke of a brake pedal, and

the brake controller determines that the brake operating amount by the driver has increased by detecting an increase in the stroke of the brake pedal.

5. The apparatus according to claim 1, wherein

the parameter is pressure in a master cylinder, and

the brake controller determines that the brake operating amount by the driver has increased by detecting an increase in the pressure in the master cylinder.

6. The apparatus according to claim 1, wherein

the parameter is a deceleration of the vehicle, and

the brake controller determines that the brake operating amount by the driver has increased during braking force limiting by determining that a deceleration at the start of the braking force limiting has increased by more than a predetermined value.

7. The apparatus according to claim 6, wherein

the brake controller determines if the deceleration is equal to or lower than a threshold value when the deceleration at the start of the braking force limiting has not increased by more than the predetermined value;

and

cancels the braking force limiting when the deceleration is equal to or lower than the threshold value.

8. A vehicular brake control method, comprising:

determining a brake operating amount by a driver;

limiting braking forces applied to rear wheels of the vehicle in comparison with braking forces applied to front wheels when the vehicle is in a predetermined driving state;

incorporating a value of a parameter, that changes according to the brake operating amount, into a threshold value for determining whether the braking forces applied to the rear wheels is increased during the braking force limiting; and

increasing the braking forces applied to the rear wheels, if the value of the parameter is larger than the incorporated threshold value during the braking force limiting.

9. The method according to claim 8, further comprising:

determining that the vehicle is in the predetermined driving state when the deceleration of the vehicle is equal to or higher than a threshold value, and performing the braking force limiting.

10. The method according to claim 8, wherein the parameter is the deceleration, and the method further comprises

determining that the brake operating amount by the driver has increased by determining that the deceleration of the vehicle has increased.

11. The method according to claim 8, wherein the parameter is a stroke of a brake pedal, and the method further comprises

determining that the brake operating amount by the driver has increased by detecting an increase in the stroke of the brake pedal.

12. The method according to claim 8, wherein the parameter is pressure in a master cylinder, and the method further comprises

determining that the brake operating amount by the driver has increased by detecting an increase in pressure in a master cylinder.

13. The method according to claim 8, wherein the parameter is a deceleration, and the method further comprises

determining that the brake operating amount by the driver has increased during braking force limiting by determining that the deceleration at the start of the braking force limiting has increased by more than a predetermined value.

14. The method according to claim 13, further comprising:

determining if the deceleration is equal to or lower than a threshold value when the deceleration at the start of the braking force limiting has not increased by more than the predetermined value; and

canceling the braking force limiting when the deceleration is equal to or lower than the threshold value.