METHOD FOR OPERATING A VEHICLE

Abstract

A method for operating a vehicle, a braking device, including a parking brake as one element and a brake booster as another element for actuating a service brake of the vehicle, being actuated to decelerate the vehicle, so that a braking force, which decelerates the vehicle, is generated with the aid of the braking device, during deceleration of the vehicle, at least one of the elements of the baking device being controlled in such a way that the generated braking force varies over time. A control device for a braking device of a vehicle, a braking system for a vehicle, and a computer program, are also described.

Claims

1-9. (canceled)

10. A method for operating a vehicle, comprising: actuating a braking device, the braking device including a parking brake as one element and a brake booster as another element for actuating a service brake of the vehicle, the braking device being actuated to decelerate the vehicle, so that a braking force, which decelerates the vehicle, is generated by the braking device; and while the vehicle is being decelerated, controlling at least one of the elements of the braking device in such a way that the generated braking force is varied over time.

11. The method as recited in claim 10, wherein, while the vehicle is being decelerated, an actual longitudinal acceleration of the vehicle is measured, and the generated braking force is varied over time depending on the measured actual longitudinal acceleration, in such a way that the actual longitudinal acceleration of the vehicle is within a defined setpoint longitudinal acceleration range to prevent a vehicle wheel from locking.

12. The method as recited in claim 10, wherein, while the vehicle is being decelerated, an actual yaw rate of the vehicle is measured, and the generated braking force is varied over time depending on the measured actual yaw rate, in such a way that the actual yaw rate of the vehicle is within a defined setpoint yaw rate range to prevent skidding of the vehicle.

13. The method as recited in claim 12, wherein when the measured actual yaw rate is greater than a defined yaw rate threshold value, automatic counter-steering takes place with the aid of a steering of the vehicle to reduce the actual yaw rate of the vehicle below the defined yaw rate threshold value.

14. The method as recited in claim 10, wherein, during the deceleration of the vehicle, an actual transverse acceleration of the vehicle is measured, and the generated braking force is varied over time depending on the measured actual transverse acceleration in such a way that the actual transverse acceleration of the vehicle is within a defined setpoint transverse acceleration range to prevent skidding of the vehicle.

15. The method as recited in claim 10, wherein the at least one element of the braking device is controlled during the deceleration only in such a way that the generated braking force is varied over time when a failure of an automatic anti-lock system of the vehicle is detected.

16. A control device for a braking device of a vehicle, the control device configured to: actuate a braking device, the braking device including a parking brake as one element and a brake booster as another element for actuating a service brake of the vehicle, the braking device being actuated to decelerate the vehicle, so that a braking force, which decelerates the vehicle, is generated by the braking device; and while the vehicle is being decelerated, control at least one of the elements of the braking device in such a way that the generated braking force is varied over time.

17. A braking system for a vehicle, comprising: a braking device, which has a parking brake as one element and a brake booster as an additional element for actuation of a service brake of the vehicle; and a control device control device for a braking device of a vehicle, the control device configured to actuate the braking device to decelerate the vehicle, so that a braking force, which decelerates the vehicle, is generated by the braking device, and while the vehicle is being decelerated, control at least one of the elements of the braking device in such a way that the generated braking force is varied over time.

18. A non-transitory computer readable storage medium storing a computer program including program code for operating a vehicle, the program code, when executed by a computer, causing the computer to perform: actuating a braking device, the braking device including a parking brake as one element and a brake booster as another element for actuating a service brake of the vehicle, the braking device being actuated to decelerate the vehicle, so that a braking force, which decelerates the vehicle, is generated by the braking device; and while the vehicle is being decelerated, controlling at least one of the elements of the braking device in such a way that the generated braking force is varied over time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] FIG. 1 shows a flow chart of a method for operating a vehicle.

[0047] FIG. 2 shows a flow chart of another method for operating a vehicle.

[0048] FIG. 3 shows a flow chart of another method for operating a vehicle.

[0049] FIG. 4 shows a control device.

[0050] FIG. 5 shows a braking system for a vehicle.

[0051] FIG. 6 shows a vehicle.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0052] FIG. 1 shows a flow chart of a method for operating a vehicle.

[0053] According to a step 101, a parking brake of the vehicle is actuated as an element of a braking device to decelerate or brake the vehicle. In a step 103, the actuated parking brake generates a braking force. The braking force acts in particular on one wheel or preferably on multiple wheels of the vehicle. In a step 105, the parking brake is controlled during the deceleration of the vehicle with the aid of the parking brake, i.e., while the parking brake is actuated, in such a way that the generated braking force is varied, i.e., modulated, over time in a step 107.

[0054] Due to the variation or modulation over time, locking of the wheels of the vehicle is advantageously counteracted. Swerving or skidding of the vehicle may be advantageously reduced or prevented. In particular this achieves better steerability and better directional stability. Therefore, a risk of a side impact with an obstacle may be further reduced in an advantageous manner.

[0055] In addition, it is pointed out that a compromise has been made: the longitudinal guidance is improved, but the fact that the maximum possible deceleration is reduced, if necessary, is accepted. However, this is conclusive since a front impact generally has a lower risk potential with today's vehicles. Furthermore, this compromise is applicable only in the event of failure of the ABS or ESP for the service brake. The possible disadvantage (lower maximum possible deceleration) outweighs the advantage (improved longitudinal guidance).

[0056] In a specific embodiment not shown here, it may be provided that in step 101, instead of or in addition to actuation of the parking brake, a brake booster is actuated as an additional element of the braking device. The brake booster actuates a service brake of the vehicle, thereby generating a braking force, which decelerates the vehicle. It is provided that the brake booster is controlled in such a way that it actuates the service brake, so that the generated braking force is varied or modulated over time. These advantages are obtained in a manner similar to the preceding discussion in conjunction with the actuation of the parking brake.

[0057] FIG. 2 shows a flow chart of another method for operating a vehicle.

[0058] According to a step 201, a parking brake is actuated for decelerating the vehicle. The actuated parking brake generates a braking force, which decelerates the vehicle according to a step 203. According to a step 205, an actual longitudinal acceleration of the vehicle is measured during the deceleration of the vehicle with the aid of the parking brake. In a step 207, the parking brake is controlled during the deceleration of the vehicle with the aid of the parking brake in such a way that, according to a step 209, the generated braking force is varied over time. This variation over time is carried out here as a function of the measured actual longitudinal acceleration. This is the case in particular, in that the actual longitudinal acceleration of the vehicle is within a defined setpoint longitudinal acceleration range to prevent a vehicle wheel from locking or to again release a locked vehicle wheel.

[0059] Thus, for example, the generated braking force generated is reduced when the measured actual longitudinal acceleration is greater than an upper limit of the setpoint longitudinal acceleration range, because a deceleration of the vehicle is generally so great that one or multiple wheels are locked. Inasmuch as the generated braking force is reduced in this case, the braking effect is advantageously also reduced, which in turn advantageously results in the actual longitudinal acceleration of the vehicle being reduced.

[0060] For example, if the measured actual longitudinal acceleration is below a lower limit of the setpoint longitudinal acceleration range, then the generated brake force is increased until the actual longitudinal acceleration of the vehicle is again within the setpoint longitudinal acceleration range. This advantageously increases a braking force, which increases the braking effect. Therefore, an actual longitudinal acceleration of the vehicle is advantageously increased or elevated. The braking distance of the vehicle may thus be shortened advantageously.

[0061] The preceding discussions in conjunction with FIG. 2 are applicable similarly if the longitudinal acceleration is replaced or supplemented by the yaw rate and/or the transverse acceleration. In addition, the preceding discussion is also applicable in conjunction with FIG. 2 similarly for the case when the brake booster is actuated in addition to or instead of the actuation of the parking brake, so that the booster actuates the service brake of the vehicle, the brake booster being controlled in a manner similar to that in FIG. 1, in such a way that it actuates the service brake so that the generated braking force is varied or modulated over time. The advantages are obtained in conjunction with the actuation of the parking brake in a manner similar to that in the preceding discussions.

[0062] FIG. 3 shows a flow chart of another method for operating a vehicle.

[0063] According to a step 301, a parking brake is actuated to decelerate the vehicle, which generates a braking force, which decelerates the vehicle according to a step 303. In a step 305, an actual yaw rate of the vehicle is measured during the deceleration of the vehicle with the aid of the parking brake. In a step 307, the parking brake is controlled during the deceleration of the vehicle, in such a way that the generated braking force is varied over time according to a step 309. This variation is carried out in particular as a function of the measured actual yaw rate.

[0064] In addition, in step 305, a test step is also provided, in which it is checked whether the measured actual yaw rate is less than or equal to a defined yaw rate threshold value. If the measured actual yaw rate is greater than a defined yaw rate threshold value, then automatic counter-steering of the vehicle takes place with the aid of the steering of the vehicle in a step 311 to reduce the actual yaw rate of the vehicle below the defined yaw rate threshold value. In other words, this means in particular that counter-steering takes place in such a way that the actual yaw rate of the vehicle is reduced. This means in particular that automatic counter-steering takes place automatically against the actual yaw rate with the aid of the steering of the vehicle.

[0065] Steps 307 and 309 may be carried out simultaneously with step 311, for example. Steps 307 and 309 may be carried out in particular only after step 311, in particular after the counter-steering has ended.

[0066] If it is found in test step 305 that the measured actual yaw rate is less than or equal to the defined yaw rate threshold value, then step 311 is not carried out but instead only steps 307 and 309 are carried out.

[0067] The preceding discussions in conjunction with FIG. 3 also apply similarly for the case when the brake booster is actuated in addition to or instead of actuation of the parking brake, so that the booster actuates the service brake of the vehicle, whereby the brake booster is controlled similarly to FIG. 1 or 2, so that it actuates the service brake in such a way that the generated braking force is varied or modulated over time. Similar to the preceding discussions, the advantages are derived in conjunction with the actuation of the parking brake.

[0068] FIG. 4 shows a control device 401 for a braking device of a vehicle.

[0069] Control device 401 is configured to carry out the method for operating a vehicle.

[0070] FIG. 5 shows a braking system 501 for a vehicle.

[0071] Braking system 501 includes a braking device 502, which includes a parking brake 503 as one element and a brake booster 505 as another element for actuating a parking brake (not shown). Braking system 501 includes control device 401 according to FIG. 4, which is designed to control at least one of the elements of braking device 502 by the method according to the present invention.

[0072] In one specific embodiment, not shown here, it may be provided that braking system 501 includes the service brake, which is designed independently of parking brake 503 and functions and may be operated independently of the parking brake. The service brake and parking brake 503 supply a braking effect or braking force independently of one another.

[0073] FIG. 6 shows a vehicle 601.

[0074] Vehicle 601 includes braking system 501 according to FIG. 5. Parking brake 503 has a braking or decelerating effect on rear wheels 603 and/or front wheels 605 of vehicle 601. Parking brake 503 is therefore in corresponding operating connection with front wheels 605 and rear wheels 603.

[0075] A service brake (not shown here) of the vehicle may be actuated with the aid of brake booster 505, so that the service brake generates a braking force, which decelerates vehicle 601. The service brake here acts on rear wheels 603 and/or front wheels 605.

[0076] Vehicle 601 includes a sensor system 607 (which may also be referred to in general as a sensor device), which may include one or multiple inertial sensor(s). The inertial sensors may be in particular the same or preferably different. An inertial sensor may be, for example, an acceleration sensor (for example, a transverse acceleration sensor or a longitudinal acceleration sensor) or a yaw rate sensor. Acceleration of the vehicle, in particular a longitudinal and/or transverse acceleration may be measured advantageously with the aid of sensor system 607, which may be referred to in general as an inertial sensor system or as an inertial sensor device. In particular the yaw rate of the vehicle may be measured with the aid of inertial sensor system 607. Depending on the measured accelerations and/or yaw rates, the braking force generated with the aid of parking brake 503 is then varied or modulated over time.

[0077] In a specific embodiment, not shown here, it may be provided that control device 401 is configured to control a steering of the vehicle. This is the case in particular when a measured actual yaw rate of the vehicle is greater than a defined yaw rate threshold value. This is the case in particular for counter-steering of the vehicle against the yaw according to the yaw rate of the vehicle.

[0078] The present invention thus includes in particular modulating, i.e., varying, i.e., changing over time the braking effect of the parking brake or the service brake, which is actuated with the aid of the brake booster. This is preferably the case in the event of an ABS failure.