Method for operating an automated parking brake

Patent metadata

Field	Value
Publication number	US-10351113-B2
Application number	US-201715656908-A
Country	US
Kind code	B2
Filing date	Jul 21, 2017
Priority date	Jul 26, 2016
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A method for operating an automated parking brake in a motor vehicle with a hydraulic actuator for generating a hydraulic force component and an electromechanical actuator for generating an electromechanical force component, includes overlaying the hydraulic force component and the electromechanical force component to achieve a total clamping force for a parking brake process. The method further includes setting, on occurrence of a first condition, a first hydraulic pressure level, and setting, on occurrence of a second condition, a second hydraulic pressure level. The method also includes holding substantially constant the set first hydraulic pressure level with the hydraulic actuator until the occurrence of the second condition.

First claim

What is claimed is:

1. A method for operating an automated parking brake in a motor vehicle having a hydraulic actuator for generating a hydraulic force component and an electromechanical actuator for generating an electromechanical force component, comprising:
overlaying the hydraulic force component and the electromechanical force component to achieve a total clamping force for a parking brake process;
setting a first hydraulic pressure level on occurrence of a first condition;
setting a second hydraulic pressure level on occurrence of a second condition, the second hydraulic pressure level different from the first hydraulic pressure level;
holding substantially constant the set first hydraulic pressure level with the hydraulic actuator until the occurrence of the second condition; and
checking whether the second hydraulic pressure level is correctly set by taking into account a first value of the electromechanical actuator representing a force curve and/or a current gradient during a first time interval, and a second value of the electromechanical actuator representing a force curve and/or a current gradient during a second time interval, and comparing the first value and the second value.

2. The method according to claim 1 , further comprising:
defining the first hydraulic pressure level as a pressure for stopping the vehicle; and
defining a target pressure of the automated parking brake as a pressure for parking the vehicle, wherein the second hydraulic pressure level corresponds to the defined target pressure.

3. The method according to claim 2 , further comprising:
taking into account a slope of the roadway in the defining one or more of the first hydraulic pressure level and the second hydraulic pressure level to enable one or more of stopping and parking the vehicle on a momentary roadway incline.

4. The method according to claim 1 , further comprising:
checking whether the second hydraulic pressure level is correctly set by taking into account a value of the electromechanical actuator representing a force curve and/or a current gradient.

5. The method according to claim 4 , further comprising:
taking into account values of several electromechanical actuators in the check; and
comparing the values of several electromechanical actuators, wherein the values of several electromechanical actuators represent a force curve of a respective one of the several electromechanical actuators and/or a current gradient.

6. The method according to claim 1 , further comprising:
holding substantially constant the set first hydraulic pressure level until one or more of the occurrence of the second condition by control of the hydraulic actuator and self-inhibition in a system of the hydraulic actuator.

7. The method according to claim 1 , further comprising:
activating the hydraulic actuator such that the setting of the first hydraulic pressure level, the holding substantially constant of the set first hydraulic pressure level, and the setting of the second hydraulic pressure level take place as part of a single activation.

8. The method according to claim 1 , further comprising:
identifying a parking brake request; and
closing inlet valves on a front axle of the vehicle when the parking brake request is identified, or the first hydraulic pressure level is reached.

9. The method according to claim 1 , wherein on reaching the second hydraulic pressure level until a total clamping force is achieved, the method further comprises one or more of:
holding constant the second hydraulic pressure level by further adjustment of the hydraulic actuator; and
closing at least one switchover valve associated with a rear axle of the vehicle.

10. The method according to claim 1 , further comprising:
identifying a correct setting of the second hydraulic pressure level if the first value is less than the second value.

11. The method according to claim 1 , further comprising:
determining the first and the second hydraulic pressure levels using one or more of a pressure sensor, a travel sensor, algorithms for estimating pressure, algorithms for estimating travel, and algorithms for estimating a position of a component, wherein the component is a spindle nut.

12. A method for operating an automated parking brake in a motor vehicle having a hydraulic actuator for generating a hydraulic force component and an electromechanical actuator for generating an electromechanical force component, comprising:
overlaying the hydraulic force component and the electromechanical force component to achieve a total clamping force for a parking brake process;
setting a first hydraulic pressure level on occurrence of a first condition;
setting a second hydraulic pressure level on occurrence of a second condition, the second hydraulic pressure level different from the first hydraulic pressure level;
holding substantially constant the set first hydraulic pressure level with the hydraulic actuator until the occurrence of the second condition;
checking whether the second hydraulic pressure level is correctly set by taking into account a value of the electromechanical actuator representing a force curve and/or a current gradient;
taking into account values of several electromechanical actuators in the check; and
comparing the values of several electromechanical actuators, wherein the values of several electromechanical actuators represent a force curve of a respective one of the several electromechanical actuators and/or a current gradient.

Assignees

• Bosch Gmbh Robert

Inventors

• Mannherz Edith
• Wolff Helmut

Classifications

• B60T2201/06

  Hill holder; Start aid systems on inclined road · CPC title

• B60T13/746 Primary

  and mechanical transmission of the braking action · CPC title

• B60T13/686

  in hydraulic systems or parts thereof · CPC title

• B60T13/662

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

• B60T8/245 Primary

  Longitudinal vehicle inclination · CPC title