METHOD FOR IMPRINTING HAPTIC FEEDBACK ON A BRAKE PEDAL

Abstract

A method for haptic feedback on a brake pedal of a motor vehicle. A current stability index describing the current driving situation is compared to a stored critical stability index. A haptic feedback is imprinted on the brake pedal of the motor vehicle when the ratio between the current stability index and the critical stability index exceeds a previously defined limit value.

Claims

1. A method for haptic feedback on a brake pedal of a motor vehicle, comprising: a current stability index describing the current driving situation is compared to a stored critical stability index, wherein a haptic feedback is imprinted on the brake pedal of the motor vehicle when a ratio between the current stability index and the critical stability index exceeds a previously defined limit value.

2. The method according to claim 1, wherein the current stability index is provided by an electronic stability program (ESP) of the braking system of the motor vehicle.

3. The method according to claim 1, wherein the current stability index is determined using the data provided by sensors present in the braking system and motor vehicle: pressure in the braking system, temperature in the braking system, acceleration, rotational speed of the wheels, yaw, roll, pitch, lateral acceleration, and GPS data.

4. The method according to claim 1, wherein the motor vehicle has a braking system with an actuator that can be activated by way of a regulating/control unit and that forms an operative connection with the brake pedal, wherein the haptic feedback is imprinted on the brake pedal by means of the actuator.

5. The method according to claim 3, wherein the motor vehicle has an electromechanical brake booster in the braking system that can be activated by way of a control device, wherein the haptic feedback is imprinted on the brake pedal by an intermittent powering of the electromechanical brake booster of the braking system of the motor vehicle.

6. The method according to claim 1, wherein the motor vehicle has a brake-by-wire braking system with hydraulic fallback levels and a pedal simulator that can be activated by way of a control device, wherein the haptic feedback is imprinted on the brake pedal by means of valve actuations in the hydraulic fallback level.

7. The method according to claim 1, wherein the haptic feedback is continuously enhanced with increasing approximation of the current stability index to the stored critical stability index.

8. The method according to claim 1, wherein the haptic feedback is carried out in the form of an oscillation imprinted on the brake pedal.

9. The method according to claim 7, wherein the continuous enhancement of the haptic feedback takes place through continuously increasing the frequency and/or the amplitude of the oscillation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Further advantages and application possibilities for the present invention result from the following description in conjunction with the exemplary embodiment shown in the drawing.

[0017] The following is indicated:

[0018] FIG. 1 shows a schematic representation of a braking system of a motor vehicle.

DETAILED DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 shows a braking system characterized overall with the reference number 10 for wheels 12-1 to 12-4 of a motor vehicle.

[0020] The braking system 10 is executed here as a hydraulic dual-circuit braking system and comprises, in the known type and manner, a brake pedal 14, a sensor 16 for detecting or recording a braking request of the driver, a brake booster 18, as well as a tandem brake master cylinder 20.

[0021] The tandem brake master cylinder 20 forms an operative connection with a hydraulic unit 24, by way of a first and a second hydraulic line 22, 24, with the hydraulic unit being connected to the wheels 12-1, 12-2, 12-3, and 12-4 of respectively allocated brake cylinders 26-1, 26-2, 26-3, and 26-4, via hydraulic lines 26, 28, 30, 32. The hydraulic unit 24 has multiple valves, which are not shown here, allocated to the hydraulic lines 26, 28, 30, 32, as well as an ESP control device 34 controlling and/or regulating the valves of the hydraulic lines 26, 28, 30, 32.

[0022] Furthermore, the braking system 10 comprises a control/regulating unit 36, which forms an operative connection with the ESP control device 34 on the input side via a control line 38 and which forms an operative connection with an actuator 42 allocated to the brake pedal 14 on the output side via a control line 40. A current stability index describing the current driving situation is provided to the regulating/control unit 36 by the ESP control device as an input variable via the control line 38.

[0023] The current stability index is compared to a stored critical stability index in the control/regulating control unit 36. If the comparison indicates that the ratio between the current stability index and the critical stability index is exceeding a previously defined limit value, the actuator 42 will be activated via the control line 40.

[0024] The actuator 42 causes an oscillation of the brake pedal 14, so that the driver proactively receives the haptic feedback that the driver is about to exhaust the limits of the physical driving dynamics.