Braking force control system for vehicle

• US 6,789,858 B2
• Filed: 04/26/2001
• Issued: 09/14/2004
• Est. Priority Date: 04/26/2000
• Status: Expired due to Fees

• Current Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Original Assignee: Fuji Jukogyo KK (Subaru Corp.)
• Inventors: Soejima, Yuji, Akiyama, Tohru
• Primary Examiner(s): Graham, Matthew C.
• Assistant Examiner(s): SY, MARIANO ONG
• Application Number:
  US09/842,069
• Publication Number:
  US 20010043010A1
• Time in Patent Office: 1,237 Days
• Field of Search: 303/146, 303/147, 303/155, 303/186, 303/113.5, 303/113.4
• US Class Current: 303/146
• CPC Class Codes: B60T 2250/02 Vehicle mass
• CPC Class Codes: B60T 8/1766 Proportioning of brake forces according to vehicle axle loads, e.g. front to rear of vehicle

Abstract

In a vehicle having an ABS control system, a braking control of a right and left rear wheels can be independently carried out when a lateral acceleration exceeds a lateral acceleration value set beforehand. When the ABS control is operated at one of the right and left rear wheels, the control system executes a stepwise pressure increase control which provides a stepwise pressure increase for the other rear wheel up to a braking pressure to be reached at a start of the control.

Claims

1. A braking force control system for a vehicle having a braking force applying apparatus mounted on said vehicle for actuating a hydraulic force to each wheel from each cylinder, an anti-lock brake system for preventing said braking force applying apparatus from locking when a sudden braking operation occurs, a wheel speed sensor for detecting each wheel speed and for generating a wheel speed signal, and a brake switch attached to said wheel for detecting an actuation of said hydraulic force and for outputting a brake signal, and a lateral acceleration sensor mounted on said vehicle for sensing a lateral acceleration and for generating a lateral acceleration signal, comprising:

rear wheel braking control means for independently controlling said hydraulic force to a rear left wheel or to a rear right wheel respectively; and

braking force control means responsive to said lateral acceleration signal and hydro-and-electro-mechanically connected to said braking force applying apparatus for, controlling to stepwisely increase said hydraulic force on one of said left or right wheels up to a predetermined value set at a starting time for applying said hydraulic force, by a plurality of steps of increasing and holding the hydraulic force when said anti-lock brake system applies said hydraulic force to the other of said left or right wheel so as to avoid an uncomfortable rolling motion when said vehicle abruptly turns at a high speed.

2. The braking force control system according to claim 1, wherein said braking force control means controls to stepwisely increase said hydraulic force with respect to one of left or right wheels when said anti-lock brake system applies said hydraulic force to the other of left or right wheel.

3. A braking force control method for a vehicle having a braking force applying apparatus mounted on said vehicle for actuating a hydraulic force to each wheel from each cylinder, an anti-lock brake system for preventing said braking force applying apparatus from locking when a sudden braking operation occurs, a wheel speed sensor for detecting each wheel speed, and a brake switch attached to said wheel for detecting an actuation of said hydraulic force, and a lateral acceleration sensor mounted on said vehicle for sensing a lateral acceleration comprising:

controlling said hydraulic force of a rear left wheel or a rear right wheel independently; and

increasing said hydraulic force stepwisely in a plurality of steps of increasing and holding the hydraulic force to reach a predetermined value set at a starting time of applying said hydraulic force on one of said rear left wheel or said rear right wheel when said anti-lock brake system applies said hydraulic force to the other of said left or right wheel so as to avoid an uncomfortable rolling motion when said vehicle abruptly turns at a high speed.

4. The braking force control method according to claim 3, wherein said increasing step increases said hydraulic force stepwisely with respect to the other of left or right wheels when said anti-lock brake system applies said hydraulic force to either one of left or right wheel.