Granted Patent B2

US 12,377,910 · App. 18/040,205 · Granted Aug 5, 2025

Inventors: Dominik Vogt (Meckenbeuren, DE); Ingo Dasch (Gräfelfing, DE)

Assignee: ZF Friedrichshafen AG

B62D7/159

Abstract

Claims (31)

1. A method for operating a steer-by-wire steering system of a motor vehicle having at least one steering function, an arbitration unit, and an actuator, the method comprising:

requesting, by the at least one steering function of the steer-by-wire steering system, one or more steering angle changes for at least one vehicle axle;

weighting, by the arbitration unit (AE), the one or more steering angle changes as target steering angles (SLw_i);

determining a selected target steering angle (G_SLw), taking into account at least one of the target steering angles (SLw_i);

determining that a gradient of the selected target steering angle (G_SLw) is smaller than or equal to a gradient of the at least one of the target steering angles (SLw_i) taken into account; and

setting, by the actuator of the steer-by-wire steering system, the selected target steering angle (G_SLw) for the at least one vehicle axle.

2. The method according to claim 1 , wherein requesting the one or more steering angle changes is performed as a function of a driving situation (Fzg_S) of the motor vehicle.

3. The method according to claim 2 , further comprising determining the driving situation (Fzg_S) of the motor vehicle using at least one parameter selected from: a driving mode, a steering wheel position, a steering wheel angle speed, a steering-wheel angle acceleration, a speed of the vehicle, a yaw angle speed, a transverse acceleration, a longitudinal acceleration, and a wheel steering angle of at least one wheel on an axle to be steered.

4. The method according to claim 3 , wherein determining the driving situation (Fzg_S) of the motor vehicle includes the arbitration unit taking into account signals from at least one control unit that is distinct from the steer-by-wire steering system, the signals being read in at an interval from 5 to 40 ms.

5. The method according to claim 4 , wherein the interval is 10 ms.

6. The method according to claim 1 , further comprising determining a safety factor (v_safe) as a function of a speed of the vehicle, wherein determining the safety factor (v_safe) is performed prior to determining that the gradient of the overall target steering angle (G_SLw) is smaller than or equal to the gradient of the at least one of the target steering angles (SLw_i).

7. The method according to claim 6 , wherein the safety factor (v_safe) decreases as the speed of the vehicle increases.

8. The method according to claim 6 , further comprising debouncing a result of the checking in order to determine whether G_SLw≤SLw_i or G_SLw≤SLw_i+v_safe.

9. The method according to claim 1 , wherein determining that the gradient of the selected target steering angle (G_SLw) is smaller than or equal to the gradient of the at least one of the target steering angles (SLw_i) taken into account is performed on a continuous basis.

10. The method according to claim 1 , wherein determining that the gradient of the selected target steering angle (G_SLw) is smaller than or equal to the gradient of the at least one of the target steering angles (SLw_i) taken into account is performed periodically at an interval from 1 to 20 ms.

11. The method according to claim 10 , wherein the interval is 4 ms.

12. The method according to claim 1 , wherein when determining the overall target steering angle (G_SLw), the arbitration unit (AE) carries out a superimposition (B), having regard to a first target steering angle (S_Lw 1 ) and at least one further target steering angle (S_Lw 2 ).

13. The method according to claim 12 , wherein the superimposition (B) is a function of a driving situation (Fzg_S) of the motor vehicle.

14. The method according to claim 1 , further comprising providing a control unit configured with the at least one steering function, the control unit distinct from the control unit of the steer-by-wire steering system and wherein the at least one steering function is selected from a corridor function, a parking function, a fallback function, and a driver assistance function.

15. A non-transitory computer-readable storage medium containing machine-readable code that is configured to perform the method of claim 1 when executed by the steer-by-wire steering system of the motor vehicle.

16. A steer-by-wire steering system for a motor vehicle, comprising:

a control unit with at least one steering function;

an arbitration unit; and

an actuator;

wherein the steer-by-wire steering system is configured to carry out the following method:

requesting, by the at least one steering function, one or more steering angle changes for at least one vehicle axle;

weighting, by the arbitration unit (AE), the one or more steering angle changes as target steering angles (SLw_i);

determining a selected target steering angle (G_SLw), taking into account at least one of the target steering angles (SLw_i);

determining that a gradient of the selected target steering angle (G_SLw) is smaller than or equal to a gradient of the at least one of the target steering angles (SLw_i) taken into account; and

setting, by the actuator of the steer-by-wire steering system, the selected target steering angle (G_SLw) for the at least one vehicle axle.

17. The steer-by-wire steering system according to claim 16 , wherein the steer-by-wire steering system is configured as a rear-axle steering system of the motor vehicle.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (15)