Method for Adjusting a Brake Pedal Characteristic

Abstract

A method adjusts a brake pedal characteristic of a vehicle having a brake pedal configured to generate a brake pedal deceleration demand and at least one further deceleration demand generating device to generate at least one further deceleration demand. The vehicle is configured to decelerate according to the brake pedal deceleration demand and to the at least one further deceleration demand. The method determines an achievable deceleration potential as a result of the further deceleration demand; generates a deceleration demand for adjusting the brake pedal deceleration demand at 0% brake pedal input according to the achievable deceleration potential; and adjusts the brake pedal characteristic of the vehicle.

Claims

1-15. (canceled)

16. A method for adjusting a brake pedal characteristic of a vehicle, wherein the vehicle comprises a brake pedal configured to generate a brake pedal deceleration demand and at least one further deceleration demand generating device to generate at least one further deceleration demand, wherein the vehicle is configured to decelerate according to the brake pedal deceleration demand and to the at least one further deceleration demand, wherein the method comprises the steps of: (S1): determining an achievable deceleration potential as a result of the further deceleration demand; (S2): generating a deceleration demand for adjusting the brake pedal deceleration demand at 0% brake pedal input according to the achievable deceleration potential; and (S3): adjusting the brake pedal characteristic of the vehicle.

17. The method according to claim 16, wherein the vehicle comprises a deceleration device and/or a brake unit, the deceleration device and/or the brake unit are configured to decelerate the vehicle according to the brake pedal deceleration demand and/or according to the further deceleration demand.

18. The method according to claim 17, wherein the deceleration device comprises a retarder, a brake, an endurance brake and/or an electric machine configured to decelerate the vehicle, and/or the brake unit comprises at least one mechanical brake as a friction brake, a disc brake, and/or a drum brake.

19. The method according to claim 16, wherein in step (S3), the maximum brake pedal deceleration demand of the brake pedal characteristic is set at 100% brake pedal input, or in step (S3), the maximum brake pedal deceleration demand of the brake pedal characteristic is set at a brake pedal input, which is lower than 100% brake pedal input.

20. The method according to claim 19, wherein in step (S3), a brake pedal deceleration demand of the brake pedal characteristic is set at a brake pedal input between 0% brake pedal input and the brake pedal input causing the maximum brake pedal deceleration demand.

21. The method according to claim 16, wherein the achievable deceleration potential is a maximum achievable deceleration potential.

22. The method according to claim 16, wherein the further deceleration demand generating device comprises an accelerator pedal configured for a one-pedal driving mode, a deceleration demand input device, and/or a driver assistance function.

23. The method according to claim 16, wherein the brake pedal characteristic comprises as a brake pedal deceleration demand a deceleration value, a brake torque, an actuator force, an actuator current, an actuator voltage, and/or an actuator pressure.

24. The method according to claim 16, wherein at least one of steps S1, S2, S3 is/are executed continuously.

25. The method according to claim 16, wherein all of the steps is/are executed continuously.

26. The method according to claim 16, wherein a main deceleration demand is generated based on the brake pedal deceleration demand and the at least one further deceleration demand, and the vehicle is configured to decelerate according to the main deceleration demand.

27. The method according to claim 26, wherein the main deceleration demand is generated by selecting a deceleration demand from the brake pedal deceleration demand and from the at least one further deceleration demand or by adding-up the brake pedal deceleration demand and at least one of the at least one further deceleration demand.

28. The method according to claim 16, wherein the achievable deceleration potential is determined by learning how much deceleration is being achieved by the deceleration device and/or by a combination of different deceleration devices and/or by a combination of one or more deceleration devices with the brake unit.

29. The method according to claim 28, wherein the achievable deceleration potential is determined while driving in one-pedal drive mode.

30. A device for adjusting a brake pedal characteristic of a vehicle, comprising: an interface for receiving input data comprising a deceleration demand and/or an achievable deceleration potential; an interface for providing output data comprising a target brake pedal characteristic and/or signals for adjusting the brake pedal characteristic; and a data processing unit configured to: determine the achievable deceleration potential as a result of the further deceleration demand; generate a deceleration demand for adjusting the brake pedal deceleration demand at 0% brake pedal input according to the achievable deceleration potential; and adjust the brake pedal characteristic of the vehicle.

31. A vehicle according to claim 16 that has a brake pedal characteristic adjusted, comprising: a device according to claim 30; wherein the vehicle is configured as a commercial vehicle, a truck, a trailer, a bus and/or as a combination of a towing vehicle and a trailer, and/or wherein the vehicle comprises a deceleration device and a brake unit.

32. A computer product comprising a non-transitory computer readable medium having stored thereon program code which, when executed on a data processing unit, carries out the acts of: (S1): determining an achievable deceleration potential as a result of the further deceleration demand; (S2): generating a deceleration demand for adjusting the brake pedal deceleration demand at 0% brake pedal input according to the achievable deceleration potential; and (S3): adjusting the brake pedal characteristic of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0076] FIG. 1 shows a brake pedal characteristic according to the prior art.

[0077] FIG. 2 shows another brake pedal characteristic according to the prior art.

[0078] FIG. 3 shows an adjusted brake pedal characteristic according to an embodiment of the invention.

[0079] FIG. 4 shows an adjusted brake pedal characteristic according to an additive approach the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0080] In the following, a preferred embodiment of the invention is described by the use of FIG. 3.

[0081] FIG. 3 shows adjusted brake pedal characteristics according to an embodiment of the invention.

[0082] The drawing is based on the FIGS. 1 and 2. Therefore, only the differences thereto are described in the following. Otherwise, reference is made to the description of FIGS. 1 and 2.

[0083] The adjusted brake pedal characteristics 3 are illustrated by the dotted lines, wherein two different curves of the adjusted brake pedal characteristics 3 are shown. The adjusted brake pedal characteristic 3 are the result of an adjustment according to the invention under consideration of an achievable deceleration potential 4 (shown by dotted horizontal lines) of the vehicle that is achievable by the deceleration demand generated by the accelerator pedal characteristic 2. The accelerator pedal characteristic 2 corresponds to the characteristics of FIGS. 1 and 2 and corresponds to a OPD mode.

[0084] For some reason, in particular for the reasons as described above in the general part of the description, deceleration of the vehicle according to the accelerator pedal characteristic 2 is not possible to its maximum deceleration as shown by the dotted lines. Here, the achievable deceleration potential 4 is lower than expected.

[0085] According to the invention, this achievable deceleration potential 4 is determined, in particular according to the method step S1, and the corresponding brake pedal characteristic 3 is adjusted, wherein a brake demand value of the brake pedal characteristic 3 is generated based on the achievable deceleration potential 4 according to step S2 and wherein the brake pedal characteristic 3 is adjusted accordingly in step S3. That means, that if the driver switches from the accelerator pedal to the brake pedal and increases the input by the brake pedal to decelerate the vehicle, the brake demand causing the vehicle to decelerate is generated continuously.

[0086] Further, as it can be seen in FIG. 3, the adjusted brake pedal characteristic 3 does not comprise a jerk when the brake pedal is pressed.

[0087] Further, the brake pedal characteristic 3 is adjusted in such way that at the maximum input value from the brake pedal (100% input) a maximum brake demand, in particular of 100% is generated.

[0088] FIG. 4 shows an adjusted brake pedal characteristic according to an additive approach.

[0089] This drawing is based on the drawing of FIG. 1. However, the principle described here can also be applied to the embodiments shown in FIG. 2 and FIG. 3.

[0090] According to this approach, the brake pedal deceleration demand generated according to the brake pedal characteristic 1 and the deceleration demand generated according to the accelerator pedal characteristic 2 are summed-up to the sum of deceleration demands 5. That means, the deceleration demand generated according to the accelerator pedal characteristic 2 at 0% brake pedal input is kept and the brake pedal deceleration demand generated according to the brake pedal characteristic 1 is added to this deceleration demand.

[0091] As it can be seen in FIG. 4, the brake pedal characteristic 1 was not adjusted here. As a result, a sum 5 of both demands is generated, wherein at a point A, which corresponds to a brake pedal input lower than 100%, the maximum deceleration demand for the vehicle is reached.

[0092] Therefore, the approach of adding-up the deceleration demand is preferably carried out in an emergency case, when the maximum deceleration demand has to be reached quickly, respectively at lower brake pedal inputs.

List of Reference Signs

[0093] 1 brake pedal characteristic [0094] 2 accelerator pedal characteristic [0095] 3 adjusted brake pedal characteristic [0096] 4 achievable deceleration potential [0097] 5 sum of deceleration demands [0098] A point of maximum deceleration demand [0099] A adjusted point of maximum deceleration demand [0100] B point [0101] C point [0102] D point of maximum acceleration demand