METHOD FOR OPERATING AN ELECTROMECHANICAL VEHICLE BRAKING

• US 20150360665A1
• Filed: 06/12/2015
• Published: 12/17/2015
• Est. Priority Date: 06/13/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: SVENSSON, Thomas, JURKIW, Tim
• Granted Patent: US 9,539,994 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60T 13/745 acting on a hydraulic system, e.g. a master cylinder
• CPC Class Codes: B60T 2201/03 Brake assistants
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60T 8/171 Detecting parameters used in the regulation; Measuring values used in the regulation
• CPC Class Codes: B60T 8/3255 Systems in which the braking action is dependent on brake pedal data
• CPC Class Codes: B60T 8/3275 Systems with a braking assistant function, i.e. automatic full braking initiation in dependence of brake pedal velocity
• CPC Class Codes: B60T 8/4872 pump-back systems

Abstract

A method for operating an electromechanical vehicle brake system is provided. The method comprises determining that an activation condition has been met, building an initial portion of the pre-charge pressure in the brake system, applying the initial portion of the pre-charge pressure to at least one wheel brake, building a secondary portion of the pre-charge pressure in the brake system, and adjusting the secondary portion of the pre-charge pressure to an expected braking pressure. Adjusting the secondary portion of the pre-charge pressure may include reducing the secondary portion of the pre-charge pressure.

Claims

1. A method for operating an electromechanical vehicle brake system, comprising:

determining that an activation condition has been met;

building an initial portion of the pre-charge pressure in the brake system;

applying the initial portion of the pre-charge pressure to at least one wheel brake;

building a secondary portion of the pre-charge pressure in the brake system; and

adjusting the secondary portion of the pre-charge pressure to an expected braking pressure.

2. The method as claimed in claim 1, wherein adjusting the secondary portion of the pre-pressure is based at least in part on whether a manual or an autonomous deceleration request is expected.

3. The method as claimed in claim 2, further comprising, when a manual deceleration request is expected:

detecting a travel gradient of a brake pedal; and

evaluating the detected travel gradient relative to at least one associated threshold value to establish a basis for a pre-pressure adjustment.

4. The method as claimed in claim 3, further comprising reducing the pre-pressure based on the evaluation.

5. The method as claimed in claim 4, wherein reducing the pre-pressure comprises reducing the pre-pressure by displacement of a pressure medium with a linear drive device which is connected fluid-conductively to the vehicle braking system or returning a portion of a brake fluid of the vehicle braking system, pressurized with the pre-pressure, to a storage vessel.

6. The method as claimed in claim 2, further comprising, when a manual deceleration request is expected:

detecting a TMC pressure gradient; and

evaluating the detected TMC pressure gradient relative to at least one associated threshold value to establish a basis for a pre-pressure adjustment.

7. The method as claimed in claim 6, further comprising reducing the pre-pressure based on the evaluation.

8. The method as claimed in claim 7, wherein reducing the pre-pressure comprises reducing the pre-pressure by displacement of a pressure medium with a linear drive device which is connected fluid-conductively to the vehicle braking system or returning a portion of a brake fluid of the vehicle braking system, pressurized with the pre-pressure, to a storage vessel.

9. The method as claimed in claim 2, further comprising, when an autonomous deceleration request is expected:

detecting an autonomous deceleration request; and

evaluating the autonomous deceleration request relative to at least one associated threshold value to establish a basis for a pre-pressure adjustment.

10. The method as claimed in claim 9, further comprising reducing the pre-pressure based on the evaluation.

11. The method as claimed in claim 10, wherein reducing the pre-pressure comprises reducing the pre-pressure by displacement of a pressure medium with a linear drive device which is connected fluid-conductively to the vehicle braking system or returning a portion of a brake fluid of the vehicle braking system, pressurized with the pre-pressure, to a storage vessel.

12. The method as claimed in claim 1, further comprising releasing the secondary pre-pressure without application to wheel brakes upon expiry of a predetermined time period when the expected brake process does not occur.