Braking force controlling apparatus

• US 6,409,288 B2
• Filed: 10/21/1998
• Issued: 06/25/2002
• Est. Priority Date: 04/26/1996
• 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, Yoshida, Hiroaki
• Primary Examiner(s): Graham, Matthew C.
• Application Number:
  US09/171,589
• Publication Number:
  US 20010001527A1
• Time in Patent Office: 1,343 Days
• Field of Search: 303/115.3, 303/113.4, 303/155, 303/166, 303/DIG-1-D, 303/10, 303/11, 188/DIG.1
• US Class Current: 303/155
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 8/3275 Systems with a braking assistant function, i.e. automatic full braking initiation in dependence of brake pedal velocity
• CPC Class Codes: B60T 8/4836 wherein a booster output pressure is used for normal or anti lock braking B60T8/4845, B60T8/4863, B60T8/489 take precedence
• CPC Class Codes: B60T 8/4854 pneumatic boosters

Abstract

A braking force controlling apparatus changes a magnitude of a braking force produced by a braking operation based on a speed of the braking operation. The braking force controlling apparatus is directed to maintaining a brake-assisting control even when a beginner unintentionally releases a braking operation force on a brake pedal. A hydraulic pressure sensor (40) detects a master cylinder pressure, and a maximum master cylinder pressure during the braking operation of the brake pedal (30) is stored in an ECU (10). When the master cylinder pressure is found to be below a release-judgment level of the master cylinder pressure, which is determined based on the maximum master cylinder pressure, the brake-assisting control is terminated. When the master cylinder pressure is found to be above the release-judgment level, the brake-assisting control is maintained.

Claims

1. A braking force controlling apparatus which selectively performs one of a normal control to generate a braking force by a braking operation and a brake-assisting control to generate an increased braking force larger than the braking force generating during the normal control, said apparatus comprising:

an operation quantity detection means for detecting a quantity of operation of a brake pedal;

a maximum operation quantity storage means for storing a value representative of a maximum quantity of operation of the brake pedal detected by the operation quantity detection means; and

a brake-assisting control termination judgment means for determining, based on a result of comparison of the operation quantity detected by the operation quantity detection means and the value representative of the maximum quantity stored by the maximum operation quantity storage means, whether the brake-assisting control should be terminated.

2. The apparatus according to claim 1, characterized in that the brake-assisting control termination judgment means (10, 122, 124) terminates the brake-assisting control when the braking operation quantity is smaller than a difference between the maximum quantity and a decrease quantity.

3. The apparatus according to claim 1, characterized in that the brake-assisting control termination judgment means (10, 122, 124) terminates the brake-assisting control when the braking operation quantity is smaller than a product of the maximum quantity and a decrease ratio.

4. The apparatus according to claim 1, wherein, during the brake-assisting control, the brake-assisting control termination judgment means discriminates, based on the detected braking operation quantity and the maximum quantity stored by the maximum operation quantity storage means, between intentional brake releasing operations and unintentional brake releasing operations, wherein, when the brake releasing operation is determined to be unintentional, the brake-assisting control termination judgment means maintains the brake-assisting control.

5. The apparatus according to claim 1, characterized in that the apparatus further comprises a judgment means (10, 102) for determining whether the brake-assisting control is currently being performed, wherein, when the judgment means determines that the brake-assisting control is currently being performed, the brake-assisting control termination judgment means (122) determines whether the brake-assisting control should be terminated.

6. The apparatus according to claim 2, characterized in that the apparatus further comprises a maximum quantity judgment means (116, 118, 120) for determining whether the maximum quantity of the braking operation is smaller than a predetermined quantity, wherein, when the maximum quantity is determined as being smaller than the predetermined quantity, the maximum quantity judgment means sets the decrease quantity at a relatively large value, and, when the maximum quantity is determined as being not smaller than the predetermined quantity, the maximum quantity judgment means sets the decrease quantity at a relatively small value.

7. The apparatus according to claim 3, characterized in that the apparatus further comprises a maximum quantity judgment means (116, 218, 220) for determining whether the maximum quantity of the braking operation is smaller than a predetermined quantity, wherein, when the maximum quantity is determined as being smaller than the predetermined quantity, the maximum quantity judgment means sets the decrease ratio at a relatively large value, and, when the maximum quantity is determined as being not smaller than the predetermined quantity, the maximum quantity judgment means sets the decrease ratio at a relatively small value.

8. The apparatus according to claim 1, characterized in that the operation quantity detection means (10, 40) detects the quantity of the braking operation of the brake pedal based on a master cylinder pressure supplied by a master cylinder, and the maximum operation quantity storage means (10, 112, 114) stores the maximum quantity of the braking operation based on a maximum master cylinder pressure supplied by the master cylinder.

9. The apparatus according to claim 1, characterized in that the apparatus further comprises a judgment means (104, 106) for determining whether the braking operation quantity detected by the operation quantity detection means is smaller than a predetermined first quantity, and for determining whether the braking operation quantity is larger than a predetermined second quantity, wherein, when the braking operation quantity is determined as being smaller than the predetermined first quantity or determined as being larger than the predetermined second quantity, the brake-assisting control is maintained.

10. A braking force controlling apparatus which selectively performs one of a normal control to generate a braking force by a braking operation and a brake-assisting control to generate an increased braking force larger than the braking force generated during the normal control, said apparatus comprising:

an operation quantity detection means for detecting a quantity of operation of a brake pedal;

a maximum operation quantity storage means for storing a value representative of a maximum quantity of operation of the brake pedal detected by the operation quantity detection means; and

a brake-assisting control continuation judgment means wherein, during the brake-assisting control, the brake-assisting control continuation judgment means discriminates, based on a result of comparison of the detected quantity of operation of the brake pedal and the stored value representative of maximum quantity, between intentional brake releasing operations and unintentional brake releasing operations, and wherein, when the brake releasing operation is determined to be unintentional, the brake-assisting control continuation judgment means maintains the brake-assisting control.