Method for operating a brake system, and brake system

Patent metadata

Field	Value
Publication number	US-9511752-B2
Application number	US-201214124490-A
Country	US
Kind code	B2
Filing date	Apr 16, 2012
Priority date	Jun 9, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

The invention relates to a method for operating a brake system, in particular for motor vehicles, having an electrically controllable pressure supplying device for hydraulically actuating at least one wheel brake. The pressure supplying device includes a cylinder-piston arrangement with a hydraulic pressure chamber. The piston of the cylinder-piston arrangement being movable by an electromechanical actuator in order to generate a specificable target pressure in the hydraulic pressure chamber. An actuator torque and an actuator position of the electromechanical actuator are ascertained, and a pressure value for the pressure in the hydraulic pressure chamber is determined using the actuator toque and the actuator position taking into consideration a pressure model.

First claim

The invention claimed is:

1. A method for operating a motor vehicle brake system comprising an electrically controllable pressure supplying device for hydraulically activating at least one wheel brake, wherein the pressure supplying device includes a cylinder-piston arrangement with a hydraulic pressure chamber, and a piston which can be moved by an electromechanical actuator in order to generate a predefineable setpoint pressure in the hydraulic pressure chamber, wherein the hydraulic pressure chamber is defined by the cylinder-piston arrangement, the method comprising the steps of:
detecting an actuator torque, and an actuator position, of the electromechanical actuator by means of an electronic open-loop and closed-loop control unit,
determining an estimated pressure value for a pressure in the hydraulic pressure chamber using the actuator torque and the actuator position taking into account a pressure model,
setting or adjusting a pressure in the hydraulic pressure chamber;
using the estimated pressure value, which is determined using the actuator torque and the actuator position, as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the predefineable setpoint pressure,
wherein the pressure supplying device is actuated by means of the electronic open-loop and closed loop control unit.

2. The method as claimed in claim 1 further comprising detecting a measured pressure in the hydraulic pressure chamber by means of providing a pressure sensor, at least temporarily or when a condition is met.

3. The method as claimed in claim 2 further comprising using the measured pressure as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the setpoint pressure as long as the measured pressure is lower than or equal to a second threshold value, wherein the second threshold value is higher than or equal to a first threshold value.

4. The method as claimed in claim 2 further comprising determining the estimated pressure value from the actuator torque and the actuator position on the basis of the pressure model.

5. The method as claimed in claim 4 further comprising using the estimated pressure value, which is determined from the actuator torque and the actuator position on the basis of the pressure model, as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the setpoint pressure if the measured pressure is higher than a third threshold value that is higher than a second threshold value, the second threshold value being equal or higher than a first threshold value.

6. The method as claimed in claim 4 further comprising using the estimated pressure value, which is determined from the actuator torque and the actuator position on the basis of the pressure model, as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the setpoint pressure if a failure of the pressure sensor is detected or there is no measured pressure available.

7. A method for operating a motor vehicle brake system comprising an electrically controllable pressure supplying device for hydraulically activating at least one wheel brake, wherein the pressure supplying device includes a cylinder-piston arrangement with a hydraulic pressure chamber, and a piston which can be moved by an electromechanical actuator in order to generate a predefineable setpoint pressure in the hydraulic pressure chamber, the method comprising the steps of:
detecting an actuator torque, and an actuator position, of the electromechanical actuator,
determining an estimated pressure value for a pressure in the hydraulic pressure chamber using the actuator torque and the actuator position taking into account a pressure model,
setting or adjusting a pressure in the hydraulic pressure chamber,
using the estimated pressure value, which is determined using the actuator torque and the actuator position, as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the predefineable setpoint pressure;
detecting a measured pressure in the hydraulic pressure chamber by means of providing a pressure sensor, at least temporarily or when a condition is met, and
determining or adapting at least one parameter of the pressure model on the basis of the measured pressure, the detected actuator torque and the detected actuator position.

8. The method as claimed in claim 7 , further comprising:
determining or adapting the at least one parameter of the pressure model if the measured pressure is lower than or equal to a first threshold value, and
maintaining the at least one parameter of the pressure model if the measured pressure is higher than the first threshold value.

9. The method as claimed in claim 7 wherein, in response to determining or adapting the parameters of the pressure model, changing only one of the parameters at a time or in a time interval, wherein the extent of the change of the parameter is predefined.

10. A method for operating a motor vehicle brake system comprising an electrically controllable pressure supplying device for hydraulically activating at least one wheel brake, wherein the pressure supplying device includes a cylinder-piston arrangement with a hydraulic pressure chamber, and a piston which can be moved by an electromechanical actuator in order to generate a predefineable setpoint pressure in the hydraulic pressure chamber, the method comprising the steps of:
detecting an actuator torque, and an actuator position, of the electromechanical actuator,
determining an estimated pressure value for a pressure in the hydraulic pressure chamber using the actuator torque and the actuator position taking into account a pressure model,
setting or adjusting a pressure in the hydraulic pressure chamber,
using the estimated pressure value which is determined using the actuator torque and the actuator position, as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the predefineable setpoint pressure;
detecting a measured pressure in the hydraulic pressure chamber by means of providing a pressure sensor, at least temporarily or when a condition is met,
determining the estimated pressure value from the actuator torque and the actuator position on the basis of the pressure model,
calculating an actual pressure value from the measured pressure and the estimated pressure value which is determined from the actuator torque and the actuator position on the basis of the pressure model, and
using the actual pressure value as an actual pressure for setting or adjusting the pressure in the hydraulic pressure chamber to the predefineable setpoint pressure, if the measured pressure is higher than a second threshold value that is equal or higher than a first threshold value and if the measured pressure is lower than a third threshold value.

11. The method as claimed in claim 10 , further comprising calculating the actual pressure value by weighted averaging with a weighting factor from the measured pressure and the determined estimated pressure value, wherein the weighting factor is selected as a function of the measured pressure and a measuring range end value of the pressure sensor.

12. The method as claimed in claim 10 wherein the third threshold value is selected to be lower than a measuring range end value of the pressure sensor.

13. A motor vehicle brake system, comprising:
at least one wheel brake which can be activated hydraulically, and
a pressure supplying device which can be actuated by means of an electronic open-loop and closed-loop control unit and by means of which the bra

Assignees

• Böhm Jürgen
• Continental Teves Ag & Co Ohg

Inventors

• Böhm Jürgen

Classifications

• B60T8/17 Primary

  Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} · CPC title

• B60T13/745 Primary

  acting on a hydraulic system, e.g. a master cylinder · CPC title

• B60T2270/402

  Back-up · CPC title

• B60T8/326

  Hydraulic systems · CPC title

• B60T2270/82

  Brake-by-Wire, EHB · CPC title