Brake booster and method for its operation

Patent metadata

Field	Value
Publication number	US-9604618-B2
Application number	US-201113698966-A
Country	US
Kind code	B2
Filing date	Mar 25, 2011
Priority date	May 20, 2010
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A regulatable brake booster and to a method and a control unit for operating same. Using the method for operating the brake booster, as well as the embodiment of the brake booster, a reaction on a driver may be avoided or reduced by an offset of the brake pedal or by a changed operating force in response to a change in the supporting force. The change in the supporting force is particularly an adjustment of the braking effect of an hydraulic braking system to the braking effect of a regenerative braking system.

First claim

What is claimed is:

1. A method for operating a regulatable brake booster of a hydraulic braking system, the method comprising:
applying, using the brake booster, a supporting force to an output element of the brake booster to achieve a desired output force for a given input force applied to an input element; and
when the desired output force changes for the given input force from a first output force to a second output force, deriving a revised supporting force to be applied as a function of (i) a first piece of information describing an elasticity of at least one elastic element, which is located between the input element of the brake booster and the output element, (ii) a second piece of information regarding a pressure-volume characteristics curve of the hydraulic braking system, and (iii) the given input force applied by the driver, which is applied to the input element, wherein the revised supporting force is derived so that a response of the input element to the driver's input force remains unchanged when the applied supporting force is set to the revised supporting force; and
setting the applied supporting force to the revised supporting force.

2. The method of claim 1 , wherein the revised supporting force is derived so that the change from the supporting force to the revised supporting force produces little or no displacement of the input element of the brake booster when the desired output force changes.

3. The method of claim 1 , wherein the braking system applies an additional force to the input element, and wherein the additional force counteracts an offset of the input element resulting from the change of the supporting force when the applied supporting force is set to the revised supporting force, so that the input element is held at the same position.

4. The method of claim 3 , wherein the additional force is applied by an actuator.

5. The method of claim 3 , wherein the additional force is a frictional force.

6. The method of claim 4 , wherein the additional force is applied by a brake, as at least one of a mechanically and an electrically regulated frictional force.

7. The method of claim 6 , wherein the brake is a frictional brake which acts directly or indirectly upon the input element.

8. The method of claim 1 , wherein the brake booster is part of a hydraulic partial braking system of an overall braking system, and wherein the applied supporting force produces a hydraulic braking torque that compensates for a braking torque difference between an overall braking torque and a regenerative braking torque.

9. The method of claim 1 , wherein the revised supporting force to be applied is derived using a second characteristics curve stored in the vehicle, and wherein the second characteristics curve is a function of the first and the second pieces of information.

10. The method of claim 9 , further comprising:
recalibrating the second characteristics curve in response to maintenance intervals or within the scope of checking before or at the start of the vehicle.

11. The method of claim 9 , wherein the input force applied by the driver is ascertained using a force sensor or is calculated with the aid of at least one signal of a displacement sensor of the input element.

12. A regulatable brake booster, comprising:
a brake booster arrangement that applies a supporting force to an output element of the brake booster to achieve a desired output force for a given input force applied to an input element;
wherein the brake booster arrangement is configured to derive, when the desired output force changes for the given input force from a first output force to a second output force, a revised supporting force as a function of (i) a first piece of information describing an elasticity of at least one elastic element, which is located between the input element of the brake booster and the output element, (ii) a second piece of information regarding a pressure-volume characteristics curve of a hydraulic braking system including the brake booster arrangement, and (iii) the given input force applied by the driver, which is applied to the input element, and wherein the revised supporting force is derived so that a response of the input element to the driver's input force remains unchanged when the applied supporting force is set to the revised supporting force.

13. The brake booster of claim 12 , wherein the brake booster is configured to apply the revised supporting force and an additional force, wherein the additional force is applied to the input element in response to the change from the supporting force to the revised supporting force, and wherein the applied additional force counteracts an offset of the input element resulting from the finite change from the supporting force to the revised supporting force such that the input element is held at the same position.

14. The brake booster of claim 13 , wherein the brake booster includes an additional actuator, which is configured to apply the additional force.

15. The brake booster of claim 12 , wherein the brake booster has a mechanical and/or an electromechanically operable brake, which is configured to act upon the input element of the brake booster, the additional force being applied by operating the brake.

16. A control unit for operating a brake booster of a hydraulic braking system, comprising:
a control arrangement configured to derive a supporting force to be applied to achieve a desired output force for a given input force applied to an input element, and to control the brake booster for applying the supporting force;
wherein the control arrangement is configured to perform the following:
applying, using the brake booster, the supporting force to an output element of the brake booster to achieve the desired output force for the given input force applied to the input element; and
when the desired output force changes for the given input force from the first output force to the second output force, deriving a supporting force to be applied as a function of (i) a first piece of information describing an elasticity of at least one elastic element, which is located between the input element of the brake booster and the output element, (ii) a second piece of information regarding a pressure-volume characteristics curve of the hydraulic braking system, and (iii) the given input force applied by the driver, which is applied to the input element, wherein the revised supporting force is derived so that a response of the input element to the driver's input force remains unchanged when the revised supporting force is applied.

17. The method of claim 5 , wherein the control arrangement is configured to derive an additional force to be applied by a brake to the input element, wherein the additional force is at least one of a mechanically and an electrically regulated frictional force.

18. The method of claim 1 , wherein the input force applied by the driver is ascertained using a force sensor or is calculated with the aid of at least one signal of a displacement sensor of the input element.

19. The method of claim 13 , wherein the brake booster has at least one of a mechanical operable brake and an electromechanically operable brake, which is configured to act upon the input element of the brake booster, the additional force being applied by operating the brake.

20. The method of claim 1 , wherein the input force applied by the driver and the applied supporting force cause deformations at respective areas on the elastic element, and wherein the deformations displace the out

Assignees

• Mahnkopf Dirk
• Bosch Gmbh Robert

Inventors

• Mahnkopf Dirk

Classifications

• B60W10/188

  hydraulic brakes · CPC title

• B60T1/10 Primary

  by utilising wheel movement for accumulating energy, e.g. driving air compressors · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60T13/148 Primary

  Arrangements for pressure supply · CPC title

• B60T8/3265

  with control of the booster (B60T8/3275 takes precedence) · CPC title