Method for operating a force-sensor-less electromechanical service brake of a vehicle

Patent metadata

Field	Value
Publication number	US-12479409-B2
Application number	US-202318465276-A
Country	US
Kind code	B2
Filing date	Sep 12, 2023
Priority date	Sep 12, 2022
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

In a method for operating a force-sensor-less electromechanical service brake of a vehicle, a current profile of a force-displacement characteristic is determined and stored during a closing of a parking brake when the vehicle is being parked. The current profile of the force-displacement characteristic is used during a subsequent trip to set a required braking force on the electromechanical service brake.

First claim

The invention claimed is:

1 . A method for operating a force-sensor-less electromechanical service brake of a vehicle, comprising determining a current profile of a force-displacement characteristic of the force-sensor-less electromechanical service brake by measuring a total rotation angle of a shaft of an electric motor while applying a steadily increasing unregulated current and storing during a closing of a parking brake when the vehicle is being parked, wherein the total rotation angle is directly proportional to a relative movement of friction elements of the electromechanical service brake through a rigid force transmission path; storing the determined current profile as a reference for a subsequent trip; and using the stored current profile during the subsequent trip to control the electromechanical service brake based on motor shaft rotation angle to fulfill braking requests without requiring real-time force measurement.

2 . The method according to claim 1 , wherein the parking brake is one of a force-sensor-less electromechanical service brakes of the vehicle, which force-sensor-less electromechanical service brake comprises a locking mechanism.

3 . The method according to claim 1 , wherein the current profile of the respective force-displacement characteristic is determined on all the force-sensor-less electromechanical service brakes of the vehicle during the closing of the parking brake.

4 . The method according to claim 1 , wherein the determination of the current profile of the force-displacement characteristic is carried out only for the electromechanical service brakes configured as parking brakes and the force-displacement characteristics of the other electromechanical service brakes are determined from the determined force-displacement characteristic.

5 . The method according to claim 1 , wherein, for determining the current profile of the force-displacement characteristic, an electric motor of the electromechanical service brake is activated with a steadily increasing current and a total rotation angle of a shaft of the electric motor is detected, resulting in a time profile of the total rotation angle from which the force-displacement characteristic is determined.

6 . The method according to claim 2 , wherein the current profile of the respective force-displacement characteristic is determined on all the force-sensor-less electromechanical service brakes of the vehicle during the closing of the parking brake.

7 . The method according to claim 2 , wherein the determination of the current profile of the force-displacement characteristic is carried out only for the electromechanical service brakes configured as parking brakes and the force-displacement characteristics of the other electromechanical service brakes are determined from the determined force-displacement characteristic.

8 . The method according to claim 3 , wherein the determination of the current profile of the force-displacement characteristic is carried out only for the electromechanical service brakes configured as parking brakes and the force-displacement characteristics of the other electromechanical service brakes are determined from the determined force-displacement characteristic.

9 . The method according to claim 2 , wherein, for determining the current profile of the force-displacement characteristic, an electric motor of the electromechanical service brake is activated with a steadily increasing current and a total rotation angle of a shaft of the electric motor is detected, resulting in a time profile of the total rotation angle from which the force-displacement characteristic is determined.

10 . The method according to claim 3 , wherein, for determining the current profile of the force-displacement characteristic, an electric motor of the electromechanical service brake is activated with a steadily increasing current and a total rotation angle of a shaft of the electric motor is detected, resulting in a time profile of the total rotation angle from which the force-displacement characteristic is determined.

11 . The method according to claim 4 , wherein, for determining the current profile of the force-displacement characteristic, an electric motor of the electromechanical service brake is activated with a steadily increasing current and a total rotation angle of a shaft of the electric motor is detected, resulting in a time profile of the total rotation angle from which the force-displacement characteristic is determined.

Assignees

• Zf Active Safety Gmbh

Inventors

• Marx Andreas
• Querbach Fabian

Classifications

• B60T13/746

  and mechanical transmission of the braking action · CPC title

• B60T13/74

  with electrical assistance or drive · CPC title

• B60T8/174

  characterised by using special control logic, e.g. fuzzy logic {, neural computing} · CPC title

• B60T13/741 Primary

  acting on an ultimate actuator · CPC title

• B60T8/172 Primary

  Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters {(B60T8/17551 takes precedence)} · CPC title