Electric parking brake for autonomous vehicles

Patent metadata

Field	Value
Publication number	US-2017166173-A1
Application number	US-201615210739-A
Country	US
Kind code	A1
Filing date	Jul 14, 2016
Priority date	Dec 10, 2015
Publication date	Jun 15, 2017
Grant date	—

Abstract

A vehicle parking brake system includes a power bridge. The power bridge is electrically connected to a primary power source and to a secondary power source. The power bridge has a first condition in which the primary power source is active in which the primary source is electrically connected to a parking brake actuator. The power bridge has a second condition in which the primary power source is not active in which the secondary power source is electrically connected to the parking brake.

First claim

1 . A vehicle parking brake system comprising:
a power bridge electrically connected to a primary power source and to a secondary power source and having:
a first condition in which the primary power source is active in which the primary source is electrically connected to a parking brake actuator, and
a second condition in which the primary power source is not active in which the secondary power source is electrically connected to the parking brake.

2 . The brake system of claim 1 wherein the power sources are each batteries.

3 . The brake system of claim 1 further comprising:
a primary brake electronic control unit electrically connected to the power bridge and electrically connected to the primary power source and selectively electrically connected to the secondary power source, and
a secondary brake electronic control unit electrically connected to the power bridge and electrically connected to the secondary power source.

4 . The brake system of claim 1 further comprising:
a primary brake hydraulic valve block electrically connected with primary brake electronic control unit; and
a secondary brake hydraulic valve block electrically connected with secondary brake electronic control unit.

5 . The brake system of claim 4 wherein:
the secondary brake hydraulic valve block is connected with two secondary service brakes by a hydraulic line for each secondary service brake;
the primary brake hydraulic valve block is connected with two primary service brakes by a hydraulic line for each primary service brake; and
the primary brake hydraulic valve block is connected with the secondary brake hydraulic valve block by two hydraulic lines associated with the secondary service brakes.

6 . The brake system of claim 1 wherein the parking brake actuators are electromechanical actuators.

7 . The brake system of claim 1 further comprising a high voltage battery wherein:
the primary power source includes a primary low voltage battery and a primary power converter disposed between the high voltage battery and the primary low voltage battery;
the secondary power source includes a secondary low voltage battery and a secondary power converter disposed between the high voltage battery and the secondary low voltage battery.

8 . The brake system of claim 1 further comprising:
a means for determining whether a parking brake request to apply has been received; and
a means for applying the parking brake with the connected power source when it is determined that a parking brake request to apply has been received.

9 . The brake system of claim 8 further comprising:
a means for determining whether a vehicle is operating at a speed below a parking brake application vehicle speed; and
a means for automatically slowing the vehicle when a parking brake request to apply has been received and the vehicle is not operating at a speed below a parking brake application vehicle speed.

10 . The brake system of claim 8 further comprising:
a means for determining whether a park brake request has been received; and
a means for releasing the parking brake with the connected power source when it is determined that a park brake request has been received and it is also determined that a park brake request to apply has not been received.

11 . The brake system of claim 10 further comprising:
a means for redetermining whether a park brake request has been received when it is determined that a park brake request has not been received.

12 . A brake system for a vehicle comprising:
a primary power source; a secondary power source; a power bridge with a first terminal of the power bridge electrically connected to the primary power source and a second terminal of the power bridge electrically connected to the secondary power source and the power bridge having
a first condition characterized by the primary power source being active in which the primary source is electrically connected to a primary electronics unit and
a second condition characterized by the secondary power source being inactive in which the secondary power source is electrically connected to the primary electronics unit;
a primary hydraulic brake actuation module electrically connected to the primary electronics unit in the first condition; an electric parking brake actuator electrically connected to the primary electronics unit; a secondary electronics unit electrically connected to the secondary power source; and a secondary hydraulic brake actuation module electrically connected to the secondary electronics unit, wherein in the first condition the electric parking brake is applied by the primary power source and in the second condition the electric parking brake is applied by the secondary power source.

13 . The brake system of claim 12 wherein the power sources are each batteries.

14 . The brake system of claim 12 further comprising:
a primary brake electronic control unit electrically connected to the power bridge and electrically connected to the primary power source and selectively electrically connected to the secondary power source, and
a secondary brake electronic control unit electrically connected to the power bridge and electrically connected to the secondary power source.

15 . The brake system of claim 13 wherein:
the primary hydraulic brake actuation module is electrically connected with the primary brake electronic control unit; and
a secondary hydraulic brake actuation module is electrically connected with secondary brake electronic control unit.

16 . The brake system of claim 15 wherein:
the secondary hydraulic brake actuation module is connected with two secondary service brakes by a hydraulic line for each secondary service brake;
the primary hydraulic brake actuation module is connected with two primary service brakes by a hydraulic line for each primary service brake; and
the primary hydraulic brake actuation module is connected with the secondary hydraulic brake actuation module by two hydraulic lines associated with the secondary service brakes.

17 . The brake system of claim 12 further comprising a high voltage battery wherein:
the primary power source includes a primary low voltage battery and a primary power converter disposed between the high voltage battery and the primary low voltage battery;
the secondary power source includes a secondary low voltage battery and a secondary power converter disposed between the high voltage battery and the secondary low voltage battery.

18 . A method for applying a parking brake in a vehicle comprising the steps of:
receiving data from at least one of a sensor and an electronics unit; determining, based on the data received, whether a park brake request to apply signal has been received; when it is determined that a park brake request to apply signal has not been received, determining whether the primary power source is active; when it is determined that the primary power source is active, then use the primary power source to apply the parking brake; when it is determined that the primary power source is not active, then use a secondary power source to apply the parking brake; when it is determined that a park brake request to apply signal has been received, determining whether the vehicle is in a park-ready condition; when it is determined that the vehicle is not in the park-ready condition, taking action to put the vehicle in the park-ready condition and again determining whether the vehicle is in a park-ready condition; and when it is determined that the vehicle is in a

Assignees

• Ford Global Tech Llc

Inventors

• Lauffer Scott J
• Joyce John P
• Gabor Daniel A
• Abbas Samer
• El Aile Steven R

Classifications

• B60T2270/402

  Back-up · CPC title

• B60T17/221 Primary

  Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems (hydraulic pressure systems in general F15B19/00, F15B21/04; testing structures or apparatus G01M) · CPC title

• B60T13/741

  acting on an ultimate actuator · CPC title

• G05B9/02

  electric · CPC title

• B60T7/042

  by electrical means, e.g. using travel or force sensors · CPC title