Brake control system for motor vehicles

Patent metadata

Field	Value
Publication number	US-11447133-B2
Application number	US-201916591811-A
Country	US
Kind code	B2
Filing date	Oct 3, 2019
Priority date	Apr 6, 2017
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A brake control system has an electronic control unit such that, when the motor vehicle is at a standstill, an automatic parking brake function can be activated by the control unit. In the presence of an activation condition for the parking brake function, the brake pressure required for this purpose can be determined at least in a manner dependent on the longitudinal inclination and in a manner dependent on an estimated normal force distribution of all of the wheels and/or an estimated capability of all of the wheels to transmit braking and/or drive torque to the underlying surface. Here, the brake pressure can be predefined to be higher the more wheels have a reduced normal force.

First claim

What is claimed is:

1. A brake control system for a motor vehicle, comprising:
an electronic control unit configured such that:
an automatic parking brake function is activatable by the control unit in a standstill of the motor vehicle, wherein
if an activation condition for the parking brake function is present, brake pressure required for this purpose is determinable at least dependent on a longitudinal inclination and dependent on an estimated contact force distribution and/or torque transmission capability of all wheels of the motor vehicle, and wherein
the control unit detects which wheel has a contact force and/or torque transmission capability below a lower limit value, wherein a distribution of the required brake force is predetermined only to the wheels with a contact force and/or torque transmission capability above said lower limit value.

2. The brake control system according to claim 1 , wherein
the brake pressure is predetermined to be higher, the more wheels have a reduced contact force and/or torque transmission capability.

3. The brake control system according to claim 1 , wherein
the contact force and/or torque transmission capability of the individual wheels is identified by the control unit on the basis of the wheel suspension height of the individual wheels, a slip of the individual wheels, and/or a transverse inclination of the vehicle.

4. The brake control system according to claim 1 , wherein
the control unit is further configured such that:
a friction coefficient of the road surface is identifiable based on a location of the motor vehicle when the motor vehicle is held in standstill by the parking brake function, at least for the driven wheels, and
the brake pressure is also determinable dependent on the friction coefficient of the road below at least one of the driven wheels.

5. A use of the brake control system according to claim 1 , in a case of an all-wheel drive motor vehicle.

6. The use of the brake control system according to claim 5 , in a case of a defined off-road operation of the motor vehicle.

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Haerdtl Sebastian

Classifications

• B60T2240/06

  Wheel load; Wheel lift · CPC title

• B60W2040/1307

  Load distribution on each wheel suspension · CPC title

• B60W30/18118 Primary

  Hill holding · CPC title

• B60T13/662

  characterised by specified functions of the control system components · CPC title

• B60T7/122 Primary

  for locking of reverse movement · CPC title