Method and control device for controlling a power steering device and an adaptive damping system of a motor vehicle

Abstract

A method is provided to control a power steering device and an adaptive damping system of a motor vehicle. The power steering device makes available a mechanical steering angle range that is limited by steering stops. The adaptive damping system makes available a variable damping force. The damping force of the adaptive damping system is increased and a maximum achievable steering angle is simultaneously increased in case a steering stop is reached.

Claims

1. A method for controlling a power steering device and an adaptive suspension damping system of a motor vehicle comprising: establishing a mechanical steering angle range in the power steering device limited by steering stops; establishing a variable damping force in the adaptive suspension damping system; and increasing the variable damping force of the adaptive suspension damping system and a maximum achievable steering angle when a steering stop is reached.

2. The method according to claim 1, further comprising increasing the damping force such that a hard damping force characteristic is adjusted.

3. The method according to claim 1, further comprising reducing the damping force and the maximum achievable steering angle when the steering angle falls short of the steering stop.

4. The method according to claim 3, further comprising executing an active back-steering maneuver with the power steering device until the steering angle falls short of the steering stop.

5. The method according to claim 1, further comprising determining at least one piece of wheel-specific information affecting the maximum achievable steering angle, and a variation of the maximum achievable steering angle based on the at least one piece of wheel-specific information affecting the maximum achievable steering angle.

6. The method according to claim 5, wherein the at least one piece of wheel-specific information affecting the maximum achievable steering angle includes at least one of the width of a wheel of the motor vehicle or information on an attachment part on the wheel that changes the width of the wheel.

7. A non-transitory computer readable medium comprising a computer program that, when executed on a control unit in a motor vehicle, carries out the method according to claim 1.

8. A control device for controlling a power steering device and an adaptive suspension damping system of a motor vehicle comprising: a sensor configured to determine whether a steering stop is reached; a first control unit operable to control the adaptive suspension damping system and configured to increase a damping force of the adaptive suspension damping system when a steering stop is reached; and a second control unit operable to control the power steering device and configured to increase a maximum achievable steering angle when the steering stop is reached.

9. The control device according to claim 8, wherein the first control unit is configured to increase the damping force in such a way that a hard damping force characteristic is adjusted.

10. The control device according to claim 8, wherein the first control unit is configured to reduce the damping force again when the steering angle falls short of the steering stop, and wherein the second control unit is configured to reduce the maximum achievable steering angle again when the steering angle falls short of the steering stop.

11. The control device according to claim 10, wherein the power steering device is configured to actively back-steer until the steering angle falls short of the steering stop.

12. The control device according claim 8, further comprising a second sensor configured to determine at least one piece of wheel-specific information affecting the maximum achievable steering angle, and wherein the second control unit is configured to vary the maximum achievable steering angle based on the at least one piece of information affecting the maximum achievable steering angle.

13. The control device according to claim 12, wherein the at least one piece of wheel-specific information affecting the maximum achievable steering angle includes at least one of information on the width of a wheel of the motor vehicle or information on an attachment part on the wheel that changes the width of the wheel.

14. A motor vehicle comprising a power steering device, an adaptive suspension damping system and a control device according to claim 8.

15. A vehicle, comprising: a power steering system having a first steering stop corresponding to a first steering angle and a second steering stop corresponding to a second steering angle greater than the first steering angle; an adaptive suspension damping system; and a control device communicatively coupled to the power steering system and the adaptive suspension system, the control device comprising: a sensor configured to determine a steering angle of the vehicle; a first control unit operable to control a dampening force of the adaptive suspension damping system; and a second control unit operable to control a maximum achievable steering angle of the power steering device, wherein the first control unit and second control unit are configured to: set, when an angle of the steering angle is less than the first steering angle, the dampening force of the adaptive suspension damping system to a first predetermined force and set the maximum achievable steering angle to the first steering stop; set, when the angle of the steering angle is greater than or equal to the first steering angle and less than the second steering angle, the dampening force of the adaptive suspension damping system to a second predetermined force greater than the first predetermine force and set the maximum achievable steering angle to the second steering stop.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements.

(2) FIG. 1 shows a flowchart of a method for controlling a power steering device and an adaptive damping system of a motor vehicle in accordance with embodiments of the present disclosure; and

(3) FIG. 2 shows a schematic block diagram of a control device for controlling a power steeling device and an adaptive damping system of a motor vehicle in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

(4) The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description.

(5) FIG. 1 shows a flowchart of a method 1 for controlling a power steering device and an adaptive damping system of a motor vehicle according to embodiments of the present disclosure, wherein the power steering device makes available a mechanical steering angle range that is limited by steering stops and the adaptive damping system makes available a variable damping force.

(6) According to FIG. 1, the method includes the following steps. In step 2, it is initially determined that a driver of the motor vehicle steers in the direction of a steering stop, whereupon the damping force of the adaptive damping system is increased in step 3 and a maximum achievable steering angle is increased in step 4. The damping force and the steering angle may be increased simultaneously, as well as with a certain time delay.

(7) Since the adjustment of a damping force exerted upon the motor vehicle by the damping system also affects a potential wheel travel of a motor vehicle wheel or its envelope, i.e. a potential change of a clearance between the wheel suspension of the at least one steerable motor vehicle wheel and the vehicle structure of the motor vehicle or the wheel housing, the amount of a potential change of the clearance between a wheel suspension of the at least one steerable motor vehicle wheel and the vehicle structure can generally be reduced by increasing the damping forces such that the probability and therefore also the risk of the motor vehicle wheel approaching other vehicle components can be lowered, particularly while driving over roadway boundaries that are elevated with respect to a roadway surface. This is advantageous in combination with a power steering device, which makes available a mechanical steering angle range that is limited by steering stops, for example while slowly maneuvering the motor vehicle in constricted areas, because additional steering rack travel can be released and a turning radius of the motor vehicle therefore can also be optimized in case a driver of the motor vehicle drives over a roadway boundary that is elevated with respect to a roadway surface, for example, while the tires are fully turned. This in turn makes it possible to minimize a required active back-steering maneuver by the power steering device, which could be perceived as irritating by the driver of the motor vehicle, or to at least carry out this back-steering maneuver slower.

(8) According to the embodiments of FIG. 1, the step 3 of increasing the damping force includes an increase of the damping force such that a hard damping force characteristic is adjusted.

(9) In addition, the method 1 according to the embodiments of FIG. 1 also includes a step 5 of back-steering a driver of the motor vehicle until the steering angle once again falls short of the steering stop, as well as a step 6, in which the damping force and the maximum achievable steering angle are reduced again as soon as the steering angle once again falls short of the steering stop. The damping force and the maximum achievable steering angle particularly are reset to the previous adjustments as soon as the steering angle once again falls short of the steering stop such that the regular control mode, which is optimally adapted to the motor vehicle and/or the driving situation, can be resumed as soon as an optimization of the turning radius is no longer required.

(10) FIG. 2 shows a schematic block diagram of a control device 10 for controlling a power steering device 11 and an adaptive damping system 12 of a motor vehicle according to embodiments of the present disclosure. The power steering device 11 makes available a mechanical steering angle range that is limited by steering stops and the adaptive damping system 12 makes available a variable damping force. According to FIG. 2, the control device 10 features a sensor 13 configured to determine whether a steering stop is reached, a first control unit 14 that controls the damping system 12 and is configured to increase the damping force of the adaptive damping system 12 in case a steering stop is reached, as well as a second control unit 15 that controls the power steering device 11 and is designed for increasing the maximum achievable steering angle in case the steeling stop is reached.

(11) According to the embodiments of FIG. 2, the first control unit 14 for controlling the damping system 12 is designed for increasing the damping force in such a way that a hard damping force characteristic is adjusted.

(12) According to the embodiments of FIG. 2, the power steeling device 11 is furthermore designed for actively back-steering until the steering angle once again falls short of the steering stop and therefore designed for actively back-steering from the oversteering range, wherein this active back-steering maneuver can be carried out slower than in motor vehicles, in which a damping force of an active damping system is not increased simultaneously with an increase of the maximum achievable steering angle and it is therefore absolutely imperative to reduce a steering rack travel of the steering system in order to prevent a motor vehicle wheel from approaching the vehicle structure. This back-steering maneuver consequently is no longer perceived as annoying or irritating by a driver of the motor vehicle such that the comfort for the driver of the motor vehicle can be additionally optimized.

(13) In these embodiments, the first control unit 14 is furthermore designed for reducing the damping force again as soon as the steering angle once again falls short of the steering stop. The second control unit 15 is furthermore designed for reducing the maximum achievable steering angle again as soon as the steering angle once again falls short of the steering stop.

(14) According to FIG. 2, the control device 10 furthermore features a second sensor 16 configured to determine at least one piece of wheel-specific information affecting the maximum achievable steering angle. The second control unit 15 is designed for also varying the maximum achievable steering angle based on the at least one piece of wheel-specific information affecting the maximum achievable steering angle.

(15) According to the embodiments of FIG. 2, the at least one piece of wheel-specific information affecting the maximum achievable steering angle consist of information on the width of a wheel of the motor vehicle, as well as information on an attachment part on the wheel that changes the width of the wheel.

(16) While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.