Electro-mechanical brake system and control method thereof

Patent metadata

Field	Value
Publication number	US-12415487-B2
Application number	US-202318542636-A
Country	US
Kind code	B2
Filing date	Dec 16, 2023
Priority date	Jul 25, 2023
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

The disclosure relates to an electro-mechanical brake system including: an electro-mechanical brake configured to generate a braking force in each wheel according to a pedal effect applied to a brake pedal; a brake control unit configured to determine whether a wheel slip has occurred based on a wheel speed sensor values received from wheel speed sensors installed in wheels of a vehicle to set activation or deactivation of Anti-lock Braking System (ABS) control, and activate the ABS control on the electro-mechanical brake according to occurrence of a wheel slip, wherein the brake control unit is configured to obtain a first target wheel torque based on a wheel slip value and a road surface condition upon activation of the ABS control, and obtain a second target wheel torque by recalculating the first target wheel torque based on a communication delay and a mechanical response of the electro-mechanical brake.

First claim

What is claimed is:

1. An electro-mechanical brake system comprising:
an electro-mechanical brake configured to generate a braking force in each wheel according to a pedal effect applied to a brake pedal;
a brake control unit configured to determine whether a wheel slip has occurred based on wheel speed sensor values received from wheel speed sensors installed in wheels of a vehicle to set activation or deactivation of Anti-lock Braking System (ABS) control, and activate the ABS control on the electro-mechanical brake according to occurrence of a wheel slip,
wherein the brake control unit is configured to:
obtain a first target wheel torque based on a wheel slip value and a road surface condition upon activation of the ABS control, and
obtain a second target wheel torque by recalculating a target wheel torque based on the first target wheel torque, a communication delay, and a mechanical response of the electro-mechanical brake.

2. The electro-mechanical brake system of claim 1 , wherein the brake control unit is further configured to:
obtain the wheel slip value based on wheel speed sensor values,
determine whether a wheel slip has occurred based on the wheel slip value, and
perform the ABS control on the electro-mechanical brake based on occurrence of the wheel slip.

3. The electro-mechanical brake system of claim 2 , wherein the brake control unit is further configured to obtain the wheel slip value based on a value resulting from dividing a difference between wheel speed values by the vehicle speed.

4. The electro-mechanical brake system of claim 2 , wherein the brake control unit is further configured to:
determine, according to the wheel slip value being greater than a first threshold value, occurrence of a wheel slip to activate the ABS control, and
deactivate the ABS control according to the wheel slip value maintained to be smaller than a second threshold value for a preset time.

5. The electro-mechanical brake system of claim 1 , wherein the brake control unit is further configured to obtain the second target wheel torque by recalculating the target wheel torque in a pattern manner based on the first target wheel torque, a communication delay, and a mechanical response of the electro-mechanical brake.

6. The electro-mechanical brake system of claim 5 , wherein the brake control unit is further configured to:
obtain the second target wheel torque by subtracting a reference torque decrease amount from the first target wheel torque based on a decrease of the first target wheel torque, and
limit a magnitude of an increase amount of the second target wheel torque based on an increase of the first target wheel torque.

7. The electro-mechanical brake system of claim 6 , wherein in an initial control loop of the ABS control, the first target wheel torque and the second target wheel torque are identical to a required wheel torque from a driver or Advanced Driver Assistance Systems (ADAS).

8. The electro-mechanical brake system of claim 1 , wherein the brake control unit is further configured to transmit a required wheel torque from a driver or Advanced Driver Assistance Systems (ADAS) to the electro-mechanical brake according to non-occurrence of a wheel slip.

9. The electro-mechanical brake system of claim 1 , wherein the electro-mechanical brake includes an Electronic Control Unit (ECU) configured to perform torque feedback control based on the second target wheel torque or the required wheel torque.

10. A method for controlling an electro-mechanical brake system for generating a braking force in each wheel according to a pedal effort applied to a brake pedal, comprising:
determining whether a wheel slip has occurred based on wheel speed sensor values received from wheel speed sensors installed in wheels of a vehicle to set activation or deactivation of Anti-lock Braking System (ABS) control; and
activating the ABS control on the electro-mechanical brake according to occurrence of a wheel slip,
wherein the activating of the ABS control further comprises:
obtaining a first target wheel torque based on a wheel slip value and a road surface condition;
obtaining a second target wheel torque by recalculating a target wheel torque based on the first target wheel torque, a communication delay, and a mechanical response of the electro-mechanical brake; and

performing torque feedback control based on the second target wheel torque.

11. The method of claim 10 , wherein the determining of whether the wheel slip has occurred to set the activation or deactivation of the ABS control comprises:
obtaining the wheel slip value based on the wheel speed sensor value;
comparing the wheel slip value with a first threshold value; and
determining occurrence of a wheel slip according to the wheel slip value being greater than the first threshold value to activate the ABS control.

12. The method of claim 11 , further comprising:
determining non-occurrence of a wheel slip according to the wheel slip value being not greater than the first threshold value and
transmitting a required wheel torque from a driver or Advanced Driver Assistance Systems (ADAS) to the electro-mechanical brake.

13. The method of claim 12 , further comprising performing torque feedback control based on the required wheel torque.

14. The method of claim 10 , wherein the obtaining of the second target wheel torque comprises obtaining the second target wheel torque by recalculating the target wheel torque in a pattern manner based on the first target wheel torque, a communication delay, and a mechanical response of the electro-mechanical brake.

15. The method of claim 14 , wherein the obtaining of the second target wheel torque further comprises:
initializing the wheel torque increase time according to a decrease of the first target wheel torque; and
obtaining the second target wheel torque by subtracting a reference torque decrease amount from the first target wheel torque according to a second target wheel torque in a previous control loop being greater than the first target wheel torque.

16. The method of claim 15 , wherein, in an initial control loop of the ABS control, the first target wheel torque and the second target wheel torque are identical to a required wheel torque from a driver or Advanced Driver Assistance Systems (ADAS).

17. The method of claim 15 , further comprising setting the second target wheel torque in the previous control loop to the second target wheel torque according to the second target wheel torque in the previous control loop being not greater than the second target wheel torque.

18. The method of claim 15 , further comprising:
determining whether the wheel torque increase time has been initialized, according to the first target wheel torque not decreased;
comparing, according to the wheel torque increase time initialized, the second target wheel torque in the previous control loop with a value resulting from subtracting the reference torque increase amount from the first target wheel torque;
calculating, according to the second target wheel torque in the previous control loop being smaller than the value resulting from subtracting the reference torque increase amount from the first target wheel torque, a wheel torque increase time, and obtaining a delta torque as a torque amount to increase for each control loop; and
obtaining the second target wheel torque by decreasing the wheel torque increase time and adding the delta torque to the second target wheel torque in the previous control loop.

19. The method of claim 18 ,

Assignees

• Hl Mando Corp

Inventors

• Kim Seongnam

Classifications

• B60T8/3255

  Systems in which the braking action is dependent on brake pedal data · CPC title

• B60T2240/02

  Longitudinal grip · CPC title

• B60T2220/04

  Pedal travel sensor, stroke sensor; Sensing brake request · CPC title

• B60T2250/04

  Vehicle reference speed; Vehicle body speed · CPC title

• B60T8/171

  Detecting parameters used in the regulation; Measuring values used in the regulation · CPC title