Method and Device for Operating a Parking Brake System

Abstract

A method for operating a parking brake system includes establishing a parking brake request for a first automated parking brake constructed on a first wheel located on a first side of an axle of a motor vehicle, producing a braking force at the first wheel by activating, in response to the establishing of the parking brake request, the first automated parking brake, and activating a compensation device connecting the first wheel and a second wheel located on a second side of the axle to apply a braking force to the second wheel via the first wheel.

Claims

1. A method for operating a parking brake system, comprising: establishing a parking brake request for a first automated parking brake constructed on a first wheel located on a first side of an axle of a motor vehicle; producing a braking force at the first wheel by activating, in response to the establishing of the parking brake request, the first automated parking brake; and activating a compensation device connecting the first wheel and a second wheel located on a second side of the axle to apply a braking force to the second wheel via the first wheel.

2. The method according to claim 1, further comprising: activating the compensation device when the parking brake request is established such that the activation of the compensation device is carried out prior to activation of the first automated parking brake.

3. The method according to claim 2, wherein activating the compensation device comprises: activating the compensation device when a wheel rotation of at least one of the first wheel and the second wheel is determined

4. The method according to claim 2, wherein applying the braking force to the second wheel comprises: applying a variable braking force to the second wheel by the activation of the compensation device.

5. The method according to claim 2, wherein applying the braking force results in a braking action, the method further comprising: adjusting a uniformity of the braking action while applying the braking force to the second wheel.

6. The method according to claim 5, wherein adjusting the uniformity of the braking action comprises: adjusting the uniformity of the braking action based upon wheel speed information.

7. The method according to claim 6, further comprising: analyzing a wheel speed of the first wheel and analyzing a wheel speed of the second wheel to generate the wheel speed information.

8. The method according to claim 7, further comprising: analyzing wheel speeds of wheels of a second vehicle axle to generate the wheel speed information.

9. The method according to claim 1, wherein a second automated parking brake is constructed on the second wheel of the vehicle axle, the method further comprising: establishing, prior to applying the braking force to the second wheel via the first wheel, an error with the second automated parking brake.

10. A motor vehicle system for operating a parking brake system, comprising: a motor vehicle including at least one vehicle axle; a first wheel at a first side of the vehicle axle; a second wheel at a second side of the vehicle axle; an activatable compensation device operably connected to the first wheel and the second wheel; a first automated parking brake constructed on the first wheel; and a control device operably connected to the activatable compensation device, the control device configured to activate the activatable compensation device to apply a braking force to the second wheel via the first wheel in response to a braking force being produced at the first wheel in response to a parking brake request.

11. A parking brake system, comprising: a motor vehicle; at least one vehicle axle having a first wheel at one side and a second wheel at an opposite side of the at least one vehicle axle; an activatable compensation device connecting the first wheel and the second wheel; and an automated parking brake constructed on the first wheel, wherein there is no automated parking brake constructed on the second wheel.

12. The parking brake system according to claim 11, wherein the automated parking brake is the only automated parking brake of the motor vehicle.

13. The parking brake system according to claim 11, wherein the activatable compensation device is constructed as an electronically controlled locking differential.

14. The method according to claim 1, further comprising: activating the compensation device after the parking brake request is established such that the activation of the compensation device is carried out at the same time as or directly after the activation of the first automated parking brake.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] It should be noted that the features set out individually in the description can be combined with each other in any technically advantageous manner and set out additional embodiments of the disclosure. Other features and advantages of the disclosure will be appreciated from the description of embodiments with reference to the appended drawings.

[0037] In the drawings:

[0038] FIG. 1 is a schematic illustration of an embodiment of the disclosure;

[0039] FIG. 2 is an illustration of the method steps of a possible embodiment of the disclosure; and

[0040] FIG. 3 is an illustration of the method steps of an alternative embodiment of the disclosure.

DETAILED DESCRIPTION

[0041] FIG. 1 is a schematic illustration of an embodiment of the disclosure. In this instance, FIG. 1 shows a parking brake system 8 for a motor vehicle 1, wherein the motor vehicle 1 has at least one vehicle axle 4 having a first wheel 5 at one side and a second wheel 6 at the opposing side of the vehicle axle 4, wherein both wheels 5, 6 are connected to each other by means of an activatable compensation device 7 and an automated parking brake 9 is constructed only at the first wheel 5. Furthermore, the drive motor 2 is shown and may be constructed as an internal combustion engine or as an electric motor. The drive motor 2 acts via a gear mechanism 3 on the vehicle axle 4. When the parking brake 9 is activated, a braking force 11.5 is produced at the first wheel 5. When the compensation device 7 is activated, there is produced a controlled torque transmission 12 to the second wheel 6, whereby a braking force 11.6 is also produced on this wheel 6. The activation of the compensation device 7 is carried out via a control device 10.7. The activation of the parking brake 9 is carried out via a control device 10.9. For example, both control devices 10.7 and 10.9 may be structurally combined in one component or be structurally separate.

[0042] FIG. 2 is an illustration of the method steps of an embodiment of the disclosure. The method is shown in this instance for operating a parking brake system with a compensation device between two wheels of an axle and a parking brake at only one of the two wheels. In this instance, in a first step S1, the method is started. In the next step S1, a parking brake request is established. A parking brake request may, for example, be initiated by a driver request by the driver activating the parking brake switch. Alternatively, for example, in an emergency situation, a parking brake request can also be initiated automatically. An emergency situation arises, for example, when an error is established in the service brake system during driving and a braking operation is intended to be carried out. The establishment of an emergency braking situation can be carried out, for example, by evaluating video data and/or radar data. Subsequently, using the condition B1, it is verified whether all conditions for carrying out a parking brake operation are (still) met. If the condition is met (Y path), in the next method step S2 the electronically controlled locking differential is activated. This is intended to be understood to mean that the locking differential is closed. In the next method step S3, the parking brake is activated. This is intended to be understood to mean that the parking brake actuator is activated in the Close direction. Where applicable in this instance, a controlled or adjusted operation of the parking brake can also be carried out by means of the control device, with closure phases and release phases. With the condition B2, it is verified whether the target clamping force or the desired deceleration is achieved. If the condition B2 is complied with (Y path), the method is terminated with the step END. If the condition B2 is not met (N path), the parking brake actuator continues to be activated as described in the method step S3. It is further conceivable thatif the condition B2 is not complied withthe condition B1 is verified again and only in the event of a continued closure request (Y path of B1) are the steps S2 and S3 further carried out. If the condition B1 is not complied with (N path), in another condition B3 it is verified whether the parking brake actuator is released. If the condition B3 is met (Y path), the method is terminated with the step END. If the condition B3 is not met (N path), in a method step S4 the parking brake actuator is released before the method is terminated with the step END.

[0043] FIG. 3 is an illustration of the method steps of an alternative embodiment of the disclosure. The method steps substantially correspond to the method steps described in relation to FIG. 2. In contrast to this, the method is provided for operating a parking brake system with a compensation device between two wheels of an axle and with parking brakes on both wheels. In this embodiment, an additional condition B0 is accordingly provided, in which it is verified whether there is an error with one of the two parking brakes. The method described is accordingly carried out only when there is an error with one of the two parking brakes. The condition B0 is accordingly illustrated before the method step S1. Alternatively, there may also be provision for this to be requested only at a later time, for example, directly before method step S2.