Anti-lock brake control method and system for motor vehicles

• US 4,881,785 A
• Filed: 02/09/1989
• Issued: 11/21/1989
• Est. Priority Date: 02/09/1988
• Status: Expired due to Term

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Ushijima, Takayaki, Ishizeki, Seiichi, Igarashi, Katsumasa
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/308,135
• Time in Patent Office: 285 Days
• Field of Search: 180/197, 188/112 A, 303/94, 303/95, 303/96, 303/100, 303/103, 303/106, 303/110, 303/111, 364/426.02, 364/426.03
• US Class Current: 303/146
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02

Abstract

In anti-lock brake control of motor vehicles wherein the control of braking hydraulic pressure for braking the wheels is accomplished by repeating a control pattern in which during braking the braking hydraulic pressure is reduced and then increased in response to variations of a control speed selected from a wheel, detection means for detecting a lateral acceleration of the vehicle body is provided. When detection means detects lateral acceleration while the vehicle is braked, thereby detecting J-turn braking, a higher one of the wheel speeds of the left and right rear wheels is selected, and a lower one of the wheel speeds of the two wheels connected to one diagonally disposed hydraulic line to which the rear wheel whose speed is selected belongs is selected as a control speed to be applied to the one hydraulic line, while the wheel speed of the front wheel connected to the other hydraulic line is selected as a control speed to be applied to the other hydraulic line, whereby the wheel speed information of the floating inner rear wheel is neglected and the wheel speed information of the outer front wheel is taken as a control speed.

Claims

1. An anti-lock brake control method for a motor vehicle having an anti-lock brake control system which has a diagonally disposed dual hydraulic line system and which accomplishes the control of braking hydraulic pressure for braking the wheels of the vehicle, by repeating a control pattern in which during braking the lower one of the wheel speeds of the two wheels connected to the same hydraulic line is selected as a control speed and in which, in response to variations of said control speed, the braking hydraulic pressure in the same hydraulic line is reduced and then increased, said method comprising the steps of:

providing detection means for detecting a J-turn braking state of the vehicle;

selecting a higher one of the wheel speeds of left and right rear wheels when said detection means detects the J-turn braking;

selecting a lower one of the wheel speeds of two wheels connected to one hydraulic line to which the rear wheel having said selected higher wheel speed belongs, as a control speed to be applied to said one hydraulic line;

selecting the wheel speed of a front wheel connected to the other hydraulic line as a control speed to be applied to said other hydraulic line; and

controlling the braking hydraulic pressures in accordance with the selected speeds, when the detection means detects the J-turn braking state, in order to stop the vehicle without skidding in a predetermined pattern.

3. The anti-lock brake system according to claim 1, wherein said means for detecting a J-turn braking state is an acceleration sensor which detects a lateral acceleration acting on the vehicle.

4. The anti-lock brake system according to claim 3, wherein the acceleration sensor is connected to a braking hydraulic pressure control circuit forming a part of said means for carrying out the control.

2. An anti-lock brake control system for a motor vehicle, comprising a dual hydraulic line system having two diagonally disposed hydraulic lines for braking wheels of the vehicle, and means for carrying out the control of braking hydraulic pressure within the hydraulic lines, by repeating a control pattern in which during braking the lower one of the wheel speeds of the two wheels connected to any one of the hydraulic lines is selected as a control speed to be applied to that hydraulic line and in which, in response to variations of the control speed, the braking hydraulic pressure is reduced and then increased, said control system comprising:

means for detecting a J-turn braking state of the vehicle;

means for selecting a higher one of the wheel speeds of left and right rear wheels and delivering the selected higher wheel speed as an output;

means for selecting a lower one of the wheel speeds of two wheels connected to one hydraulic line to which one rear wheel whose speed is selected belongs, as a control speed to be applied to said one hydraulic line; and

means for selecting the wheel speed of a front wheel connected to the other of the hydraulic lines as a control speed to be applied to said other hydraulic line,

said means for carrying out the control having means for controlling the braking hydraulic pressures in accordance with said selected speeds when said detection means detects the J-turn braking state.