Wheel steering angle adjustment device for changing the steering angle of at least one vehicle wheel

Abstract

Wheel steering angle adjusting device (10, 12) for changing the steering angle of at least one vehicle wheel (14, 16) of a vehicle (18), comprising a steering mechanism (20, 22) which includes a movably mounted steering actuating element (24) and at least one wheel connection element (26) arranged in an axial end region of the steering actuating element (24), and a steering actuator (28, 30) which is provided for changing the position of the steering actuating element (24) in order to change the steering angle of the vehicle wheel (14, 16), wherein the steering actuating element (24) has a coupling section (32) for coupling with the steering actuator (28, 30) which defines a maximum travel that is greater than a travel required to change the steering angle of the vehicle wheel (14, 16), and wherein the steering actuator (28, 30) in conjunction with the Coupling section (32) for fine adjustment of the track of the vehicle wheel (14,16) and the wheel attachment element (26) is provided for coarse adjustment of the track of the vehicle wheel (14, 16).

Description

State of the art

[0001] The invention relates to a wheel steering angle adjustment device for changing a wheel steering angle of at least one vehicle wheel of a vehicle. Furthermore, the invention relates to a wheel steering angle adjuster comprising such a wheel steering angle adjustment device, a vehicle comprising such a wheel steering angle adjuster, a method for adjusting a track of at least one vehicle wheel of a vehicle using such a wheel steering angle adjustment device, and a method for adjusting a track of at least one vehicle wheel of a vehicle using such a wheel steering angle adjustment device.

[0002] Vehicles with conventional steering systems are known from the prior art, in which a steering handle, for example in the form of a steering wheel, is mechanically connected to a wheel steering angle adjuster in the form of a steering gear via a steering column. Furthermore, vehicles with steer-by-wire steering systems are known, which do not require a direct mechanical connection between a steering handle and the steered vehicle wheels and in which steering input is transmitted exclusively electrically. To change the wheel steering angle of a vehicle wheel, the steer-by-wire steering systems comprise a wheel steering angle adjuster in the form of a central adjuster that is electrically connected to the steering handle, or several wheel steering angle adjusters in the form of individual wheel adjusters that are electrically connected to the steering handle.

[0003] To adjust and / or readjust the track of such vehicles, an additional, external wheel alignment system is normally used, which must be laboriously attached to the vehicle on a lifting platform and by means of which the length of the tie rods can be adjusted.

[0004] In addition, DE 10 2017 221 379 A1 discloses a wheel steering angle adjusting device for changing a wheel steering angle of at least one vehicle wheel and a method for adjusting a toe-in angle of a vehicle wheel by means of the wheel steering angle adjusting device, wherein the wheel steering angle adjusting device has a steering mechanism which comprises a movably mounted steering adjusting element and at least one wheel connection element arranged in an axial end region of the steering adjusting element, and has a steering actuator which is provided to change a position of the steering adjusting element in order to change the wheel steering angle of the vehicle wheel, wherein the steering adjusting element has a coupling section for coupling to the steering actuator and the steering actuator is provided in cooperation with the coupling section for adjusting a track of the vehicle wheel.During vehicle operation, a corrective torque can be generated and applied to the vehicle wheels. The toe-in angle is preferably adjusted using the wheel steering angle adjustment device so that it is as small as possible while the vehicle is traveling straight ahead. However, this type of toe-in angle adjustment only achieves a temporary adjustment of the vehicle's track, adapted to a specific driving situation. Coarse and fine adjustment of the track, as well as permanent adjustment of the track, are not possible.

[0005] The object of the invention is, in particular, to provide a wheel steering angle adjustment device, a method for adjusting the track of at least one vehicle wheel of a vehicle using a wheel steering angle adjustment device, and a method for adjusting the track of at least one vehicle wheel of a vehicle using a wheel steering angle adjustment device with improved properties with regard to efficiency. This object is achieved by the features of claims 1, 9, 10, 11, and 13, while advantageous embodiments and further developments of the invention can be found in the subclaims. Disclosure of the invention

[0006] A wheel steering angle adjusting device for changing a wheel steering angle of at least one, in particular steerable and advantageously designed as a front wheel, vehicle wheel of a vehicle, in particular a motor vehicle, is proposed, comprising a steering mechanism which comprises a movably mounted steering adjusting element and at least one wheel connection element arranged in an axial end region of the steering adjusting element, and comprising a steering actuator which is provided to change a position of the steering adjusting element in order to change the wheel steering angle of the vehicle wheel, wherein the steering adjusting element has a coupling section for coupling to the steering actuator, which defines a maximum adjustment path which is greater than an adjustment path required to change the wheel steering angle of the vehicle wheel, and wherein the steering actuator in cooperation with the coupling section for fine adjustment of a track, preferably a toe-in angle,of the vehicle wheel, and the wheel connection element is provided for coarse adjustment of the track, preferably the toe-in angle, of the vehicle wheel. The terms "track" and "toe-in angle" in this context advantageously refer to a static track angle, particularly independent of toe-in or toe-out. This configuration can optimize efficiency, particularly maintenance efficiency, performance efficiency, adjustment efficiency, steering efficiency, energy efficiency, and / or cost efficiency. Furthermore, an advantageously flexible wheel steering angle adjustment device can be provided, whereby, in particular, a needs-based and / or situation-dependent adjustment and / or readjustment of the track can be achieved. Furthermore, maintenance costs can be advantageously reduced and the service life of the vehicle can be increased.

[0007] A "wheel steering angle adjusting device" is to be understood as at least one part, in particular a subassembly, of a wheel steering angle adjuster, in particular of a steering system and preferably of a vehicle. The wheel steering angle adjuster has an operative connection with at least one vehicle wheel and is intended in particular to transmit a steering command to the vehicle wheel by changing a wheel steering angle of at least one vehicle wheel and thereby advantageously control an orientation of the vehicle wheel and / or influence a direction of travel of the vehicle. Furthermore, the wheel steering angle adjuster can be designed in particular as a central adjuster and assigned to at least two vehicle wheels, in particular steerable ones and preferably designed as front wheels. Preferably, however, the wheel steering angle adjuster is designed as an individual wheel adjuster and assigned to exactly one vehicle wheel, in particular steerable ones and preferably designed as a front wheel.Furthermore, the steering system can be designed as a conventional steering system, in particular as an electric power steering system, and include a mechanical override. However, the steering system is preferably designed as a steer-by-wire steering system, in which a steering command, in particular from a driver, is advantageously transmitted to the vehicle wheels purely electrically.

[0008] Furthermore, a "steering mechanism" should be understood in particular as a unit which is provided for the mechanical connection of at least one vehicle wheel to a vehicle body of the vehicle. Furthermore, the steering mechanism is provided in particular for the mechanical transmission of a steering command to the at least one vehicle wheel. For this purpose, the steering mechanism comprises the steering actuating element, which is mounted in particular for movement in the axial direction, and the wheel connection element, which is in particular coupled to the steering actuating element and preferably fastened to the steering actuating element. The steering actuating element is advantageously designed as a shaft, a threaded spindle or a rack and comprises a coupling section, for example in the form of a threaded section or a toothed section, which provides an adjustment path for changing the wheel steering angle of the vehicle wheel.In this case, the maximum travel of the coupling section is greater than the travel required to change the steering angle of the vehicle wheel during vehicle operation, so that in a normal operating state and / or in a normal driving state, only a portion of the coupling section is used to change the steering angle of the vehicle wheel. The wheel connection element is advantageously designed as a rod end or as a tie rod and, in particular, comprises a fastening section for coupling to the steering actuator. Furthermore, the steering mechanism can comprise further components and / or assemblies, such as a steering mechanism housing in which at least the steering actuator is arranged.

[0009] Furthermore, a "steering actuator" is to be understood as an actuator unit that is operatively connected to the steering actuating element, in particular the coupling section, and is in particular at least partially electrically and / or electronically designed, which, in at least one operating state, is provided for a, in particular active, movement and / or adjustment of the steering actuating element and / or the wheel connection element. Preferably, the steering actuator is provided for changing a rotational position and / or an axial position of the steering actuating element. In particular, the steering actuator is provided at least to transmit an actuating torque to the steering actuating element and thereby, in cooperation with the coupling section, to enable fine adjustment of the track of the vehicle wheel.In particular, the steering actuator is provided to transmit the actuating torque to the steering actuating element and / or to interact with the coupling section in such a way that, during fine adjustment of the track of the vehicle wheel, an actuating travel of the coupling section used to change the wheel steering angle of the vehicle wheel is adjusted and an operating position and / or rest position of the steering actuating element is varied. Furthermore, the steering actuator is advantageously provided to transmit a steering torque to the steering actuating element and thereby influence a direction of travel of the vehicle. Preferably, the steering actuator is provided to provide a steering torque to assist a manual torque applied to the steering handle and / or a steering torque for the automatic and / or autonomous control of a direction of travel of the vehicle.For this purpose, the steering actuator can comprise at least one electric motor and preferably at least one coupling gear for connecting the electric motor to the steering actuator, in particular the coupling section. An “operating position and / or rest position of the steering actuator” is to be understood in particular as a position of the steering actuator after a system and / or operational start of the vehicle, after an initial initialization and / or when the vehicle is parked. “Provided” is to be understood in particular as specially programmed, designed and / or equipped. The fact that an object is provided for a specific function is to be understood in particular as meaning that the object fulfills and / or executes this specific function in at least one application and / or operating state.

[0010] The coupling section preferably comprises an adjustment range and at least one adjustment range adjacent to the adjustment range, wherein the adjustment range provides a nominally required adjustment travel for changing the wheel steering angle of the vehicle wheel and the adjustment range provides an additional adjustment travel as a lead for setting and / or readjusting the track of the vehicle wheel. Advantageously, a ratio between a longitudinal extent and / or an axial length of the adjustment range and a longitudinal extent and / or an axial length of the adjustment range is between 0.01 and 0.05. In this context, the adjustment range defines in particular a nominally required actuator stroke, which can be in the range between + / -75 mm, for example. The adjustment range defines in particular a slight additional actuator stroke, which can be in the range between + / -0.75 mm and + / -3.75 mm, for example.In particular, the coupling section can also comprise two adjustment ranges, wherein a first adjustment range is arranged on a side of the adjustment range facing away from the vehicle wheel and a second adjustment range is arranged on a side of the adjustment range facing the vehicle wheel. In the present case, the at least one adjustment range is used for fine adjustment of the track of the vehicle wheel and in particular for adapting a used adjustment path. In particular, in a first operating state, in particular prior to adjustment and / or readjustment of the track of the vehicle wheel, a first adjustment path can be determined from the adjustment range or from a part of the adjustment range and a part of the at least one adjustment range, so that in the first operating state a first partial area of ​​the coupling section is used to change the wheel steering angle of the vehicle wheel.Furthermore, in particular in a second operating state, in particular after an adjustment and / or readjustment of the track of the vehicle wheel, a second adjustment path that at least partially deviates from and / or is different from the first adjustment path can be determined from the adjustment range or from a part of the adjustment range and a part of the at least one adjustment range, so that in the second operating state, a second sub-range of the coupling section that at least partially deviates from and / or is different from the first sub-range is used to change the wheel steering angle of the vehicle wheel. This makes it possible, in particular, to achieve particularly flexible fine adjustment of the track.

[0011] Furthermore, it is proposed that the fine adjustment of the track of the vehicle wheel be performed by adjusting an axial position of the steering actuator and by controlling the steering actuator and / or automatically by the steering actuator. In particular, for the fine adjustment of the track of the vehicle wheel, an adjustment path of the coupling section used to change the wheel steering angle of the vehicle wheel is adjusted by varying an operating position and / or rest position and consequently an axial position of the steering actuator using the steering actuator. This allows, in particular, an advantageously simple and control-technically automated fine adjustment of the track to be achieved.

[0012] It is further proposed that the wheel steering angle adjustment device comprise a detection sensor system, which comprises at least one detection sensor arranged on the steering mechanism, advantageously in the form of an inductive sensor, for detecting at least one axial position of the steering actuating element. In this case, the steering actuating element preferably comprises a detection contour, for example in the form of at least one marking, at least one notch, and / or at least one elevation, which is provided to interact with the detection sensor system to detect the axial position of the steering actuating element. Furthermore, the detection sensor system is particularly provided to provide a detection signal correlated with the axial position of the steering actuating element.Based on the detection signal or based on the detection signal and at least one control and / or operating variable of the steering actuator, an absolute axial position of the steering actuator can preferably be determined. Particularly advantageously, the steering actuator is designed to take into account and / or use the detection signal of the detection sensor system when finely adjusting the track of the vehicle wheel. This can, in particular, increase the adjustment accuracy when adjusting and / or re-adjusting the track of the vehicle wheel.

[0013] Furthermore, it is proposed that the wheel connection element be attached to the steering actuator in an assembled state and be fixable in several, in particular different, axial positions for coarse adjustment of the track of the vehicle wheel. Preferably, the wheel connection element is fixable in such a way that the track of the vehicle wheel can be adjusted in 0.75 mm or 1.5 mm increments. This allows, in particular, an advantageously simple coarse adjustment of the track to be achieved.

[0014] It is also proposed that the wheel connection element for fastening to the steering actuating element comprises a fastening section with an external thread and that the steering mechanism comprises at least one screw locking element arranged in the axial end region of the steering actuating element for fixing the wheel connection element, in particular in the multiple axial positions. The fastening section is advantageously designed as a threaded pin and / or threaded extension and extends in the axial direction. In this case, the steering actuating element also has, in particular, an internal thread arranged in the axial end region and corresponding to the external thread, in particular in the form of a threaded bore, which extends in the axial direction. The screw locking element is advantageously designed as a locking ring, locking pin or, particularly advantageously, as a lock nut.This allows for an advantageously simple fixation of the wheel connection element in different axial positions.

[0015] It is further preferably proposed that the rough adjustment of the track of the vehicle wheel be performed by adjusting an axial position of the wheel connection element and manually, in particular manually, by rotating the wheel connection element. In particular, for the rough adjustment of the track of the vehicle wheel, an axial position of the wheel connection element relative to the steering control element is adjusted by manually rotating the wheel connection element, in particular by hand, in particular by 180° or 360°. This allows for an advantageously simple and rapid rough adjustment of the track.

[0016] In addition, a method for adjusting a track, preferably a toe-in angle, of at least one vehicle wheel of a vehicle by means of a wheel steering angle adjusting device, in particular the wheel steering angle adjusting device already mentioned, is proposed, wherein in a first method step a rough adjustment of the track of the vehicle wheel is carried out by adjusting an axial position of the wheel connection element and in a second method step, in particular following the first method step, a fine adjustment of the track of the vehicle wheel is carried out by adjusting an axial position of the steering actuating element, wherein for the fine adjustment of the track of the vehicle wheel an adjustment path of the coupling section used to change the wheel steering angle of the vehicle wheel is adapted by varying an operating position and / or rest position of the steering actuating element by means of the steering actuator.The method is used in particular for the initial adjustment of the track of the vehicle wheel. Alternatively or additionally, the aforementioned method can be used to adjust the track of the vehicle wheel in a workshop. Furthermore, the rough adjustment of the track of the vehicle wheel in the first method step is carried out manually, in particular by hand, by rotating the wheel connection element. The fine adjustment of the track of the vehicle wheel in the second method step is carried out in particular by controlling the steering actuator and / or automatically by the steering actuator.Preferably, in the second method step, an absolute axial position of the steering actuating element is determined using a detection signal from a detection sensor system, in particular the previously mentioned detection sensor system, and at least one control and / or operating variable of the steering actuator. This absolute axial position is transmitted to the steering actuator and / or, preferably wirelessly, to an axle measuring system for adjusting, in particular for fine adjustment, the track of the vehicle wheel. The axle measuring system is preferably designed separately or separately from the vehicle and advantageously cooperates with the steering actuator to adjust the track of the vehicle wheel. In this case, the vehicle also preferably comprises at least one computing unit, which is provided to control the wheel steering angle adjusting device and thereby, in cooperation with the steering actuator, to carry out the method for adjusting the track of the vehicle wheel.A "computing unit" is to be understood in particular as an electrical and / or electronic unit which has an information input, an information processing unit, and an information output. Advantageously, the computing unit further comprises at least one processor, at least one operating memory, at least one input and / or output means, at least one operating program, at least one control routine, at least one regulating routine, at least one calculation routine, at least one evaluation routine, and / or at least one setting or adjustment routine. In particular, the computing unit is provided to control the steering actuator to change the wheel steering angle of the vehicle wheel. Furthermore, the computing unit is provided to adapt, in the second method step for finely adjusting the track of the vehicle wheel, an actuating travel of the coupling section used to change the wheel steering angle of the vehicle wheel.In this context, the computing unit is provided at least to control the steering actuator such that an operating position and / or rest position of the steering actuating element is varied. Preferably, the computing unit is further integrated into a control unit of the vehicle and / or a control unit of the steering system, in particular in the form of a steering control unit. In principle, in the latter case, the computing unit can also be integrated into the steering actuator. This makes it possible, in particular, to achieve the advantages already mentioned. In particular, efficiency, in particular maintenance efficiency, performance efficiency, adjustment efficiency, steering efficiency, energy efficiency, and / or cost efficiency, can be optimized.

[0017] Furthermore, a method for, in particular automatic and / or automated, adjustment of a track, preferably a toe-in angle, of at least one vehicle wheel of a vehicle by means of a wheel steering angle adjustment device, in particular the wheel steering angle adjustment device already mentioned above and in particular during operation, advantageously during driving operation of the vehicle, is proposed, wherein at least one operating variable of the steering actuator is determined and compared with at least one reference variable, and wherein in the event of a deviation of the operating variable from the at least one reference variable, in particular a deviation above a threshold value, an actuating path of the coupling section used to change the wheel steering angle of the vehicle wheel is adapted to adjust the track of the vehicle wheel by varying an operating position and / or rest position of the steering actuating element by means of the steering actuator.In particular, in a first operating state, in particular prior to the adjustment of the vehicle wheel's track, a first sub-region of the coupling section is used to change the wheel steering angle of the vehicle wheel, and in a second operating state, in particular after the adjustment of the vehicle wheel's track, a second sub-region of the coupling section that at least partially deviates from and / or is different from the first sub-region is used to change the wheel steering angle of the vehicle wheel. Preferably, the operating variable is further determined during autonomous and / or automated driving and while the vehicle is traveling straight ahead, for example, while traveling on a motorway using a motorway assistance function, whereby particularly precise straight-ahead travel of the vehicle can be achieved by specifying a corresponding target trajectory.Particularly preferably, the motor torque of the steering actuator is used as the operating variable, which is required for setting and / or maintaining the position, in particular the axial position, of the steering actuating element while the vehicle is traveling straight ahead. As a reference variable, for example, a previously applied factory setting for the operating variable, preferably during straight-ahead travel of the vehicle, another operating variable of another steering actuator equivalent to the operating variable, and / or a drive torque of at least one vehicle wheel, preferably required for straight-ahead travel, can be used. Furthermore, the vehicle comprises at least one computing unit, which is provided for carrying out the method for adjusting the track of the vehicle wheel, in particular by controlling the wheel steering angle adjusting device. In this case, the computing unit is particularly provided for controlling the steering actuator to change the wheel steering angle of the vehicle wheel.In addition, the computing unit is provided to determine an operating variable of the steering actuator, preferably during operation, particularly advantageously during driving operation, of the vehicle, and to compare it with at least one reference variable in order to determine a deviation between the operating variable and the at least one reference variable. Furthermore, the computing unit is provided to adapt an actuating travel of the coupling section used to change the wheel steering angle of the vehicle wheel in the event of a deviation of the operating variable from the at least one reference variable in order to adjust the track of the vehicle wheel. In this context, the computing unit is provided to control the steering actuator in such a way that an operating position and / or rest position of the steering actuating element is varied. Preferably, the computing unit is further integrated into a control unit of the vehicle and / or a control unit of the steering system, in particular in the form of a steering control unit.In principle, in the latter case, the computing unit can also be integrated into the steering actuator. This makes it possible to achieve, in particular, the advantages already mentioned. In particular, efficiency, in particular maintenance efficiency, performance efficiency, adjustment efficiency, steering efficiency, energy efficiency, and / or cost efficiency, can be optimized.

[0018] The wheel steering angle adjustment device, the method for adjusting the track of the vehicle wheel, and the method for adjusting the track of the vehicle wheel are not intended to be limited to the application and embodiment described above. In particular, the wheel steering angle adjustment device, the method for adjusting the track of the vehicle wheel, and the method for adjusting the track of the vehicle wheel may comprise a number of individual elements, components, and units that differs from the number stated herein to fulfill a function described herein. Drawings

[0019] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention.

[0020] They show: Fig. 1a-b a vehicle with a steering system designed as an example as a steer-by-wire steering system, which comprises two wheel steering angle adjusters, each with a wheel steering angle adjusting device, in a simplified representation, Fig. 2 one of the wheel steering angle adjustment devices with a steering mechanism and a steering actuator in a detailed view, Fig. 3 an exemplary flow diagram with main method steps of a method for adjusting a track of at least one vehicle wheel of the vehicle by means of the wheel steering angle adjusting device from Fig. 2 and Fig. 4 an exemplary flow diagram with main method steps of a method for adjusting a track of at least one vehicle wheel of the vehicle by means of the wheel steering angle adjustment device from Fig. 2. Description of the embodiment

[0021] The Fig. 1a and Fig. 1b shows a simplified representation of a vehicle 18 embodied as a passenger vehicle, having a plurality of vehicle wheels 14, 16 and a steering system 54. The steering system 54 has an operative connection with the vehicle wheels 14, 16 and is provided for influencing a direction of travel of the vehicle 18. Furthermore, the steering system 54 in the present case is embodied as a steer-by-wire steering system, in which a steering command is transmitted electrically to the vehicle wheels 14, 16 in at least one operating state. In principle, however, a steering system could also be embodied as a conventional steering system, in particular as an electric power steering system.

[0022] The steering system 54 has a steering input unit 56, which is known per se and comprises a steering handle 58, for example in the form of a steering wheel, and a feedback actuator 60, which is in particular mechanically coupled to the steering handle 58. In the present case, the feedback actuator 60 is provided at least for generating a steering resistance and / or a restoring torque on the steering handle 58. Alternatively, a steering handle could also be designed as a joystick, a steering lever and / or a steering ball or the like. Furthermore, a feedback actuator could in principle also be dispensed with. It is also conceivable to dispense with a steering input unit entirely.

[0023] Furthermore, the steering system 54 has at least one wheel steering angle adjuster 48, 50. In the present case, the steering system 54 comprises, for example, two wheel steering angle adjusters 48, 50 designed as individual wheel adjusters and thus, in particular, a wheel-individual steering system. The wheel steering angle adjusters 48, 50 are at least substantially identical in design. The wheel steering angle adjusters 48, 50 are designed separately from one another and, in the present case, are particularly free of any mechanical connection. The wheel steering angle adjusters 48, 50 can be controlled independently of one another. Furthermore, the wheel steering angle adjusters 48, 50 are connected purely electrically to the steering input unit 56 and consequently to the steering handle 58. Each of the wheel steering angle adjusters 48, 50 has an operative connection with exactly one of the vehicle wheels 14, 16, in particular a front wheel.The wheel steering angle adjusters 48, 50 are provided to change a respective wheel steering angle of the corresponding vehicle wheel 14, 16 depending on a steering input. For this purpose, each of the wheel steering angle adjusters 48, 50 comprises a wheel steering angle adjusting device 10, 12. Each of the wheel steering angle adjusting devices 10, 12 comprises a steering mechanism 20, 22 and a steering actuator 28, 30 interacting with the steering mechanism 20, 22. A detailed structure of the wheel steering angle adjusting devices 10, 12 is described below with reference to . Fig. 2. In principle, a steering system could, of course, also include a wheel steering angle adjuster configured as a central adjuster. Furthermore, a steering system can also include at least four wheel steering angle adjusters configured as individual wheel adjusters. In principle, a steering system could also include a combination of a wheel steering angle adjuster configured as an individual wheel adjuster and a wheel steering angle adjuster configured as a central adjuster. Furthermore, at least one wheel steering angle adjuster could, in particular, also be assigned to a vehicle wheel configured as a rear wheel.

[0024] Furthermore, the vehicle 18 has a control unit 62. In this case, the control unit 62 is designed as a steering control unit and is therefore part of the steering system 54. The control unit 62 has an electrical connection to the wheel steering angle adjusters 48, 50. The control unit 62 also has an electrical connection to the steering input unit 56. In this case, the control unit 62 is provided at least for controlling the operation of the steering system 54.

[0025] For this purpose, the control unit 62 comprises a computing unit 64. The computing unit 64 comprises at least one processor (not shown), for example in the form of a microprocessor, and at least one operating memory (not shown). In addition, the computing unit 64 comprises at least one operating program stored in the operating memory with at least one calculation routine, at least one recognition routine, at least one control routine, and at least one evaluation routine. In principle, a control unit could also be different from a steering control unit and, for example, be designed as a single, central vehicle control unit with a central computing unit. It is also conceivable to provide separate control units for each wheel steering angle adjuster and for the steering input unit and to connect these to one another in a communicating manner.

[0026] In addition, the vehicle 18 can comprise further components and / or assemblies not shown, such as, for example, an internal vehicle sensor system for detecting at least one operating variable of the wheel steering angle adjusters 48, 50, in particular of the steering actuators 28, 30, a known on-board computer and / or a known navigation device.

[0027] In the following, with reference to the Fig. 2 a wheel steering angle adjuster 48 of the wheel steering angle adjusters 48, 50 in connection with a vehicle wheel 14 of the vehicle wheels 14, 16 assigned to the wheel steering angle adjuster 48 is described in more detail, wherein the following description can also be applied to the further wheel steering angle adjuster 50 and the further vehicle wheel 16, in particular due to the at least substantially identical construction of the wheel steering angle adjusters 48, 50.

[0028] The wheel steering angle adjuster 48 comprises, as already described above, the wheel steering angle adjusting device 10 with the steering mechanism 20 and the steering actuator 28 (in Fig. 2 only partially shown).

[0029] The steering mechanism 20 is elongated, with an extension direction of the steering mechanism 20 defining an axial direction. The steering mechanism 20 is provided for the mechanical connection of the vehicle wheel 14 to a (not shown) vehicle body of the vehicle 18. For this purpose, the steering mechanism 20 comprises a steering mechanism housing 66 with a bearing unit 68, for example in the form of a rubber bearing. Furthermore, the steering mechanism 20 is provided for transmitting a steering command to the vehicle wheel 14 and consequently for changing the wheel steering angle of the vehicle wheel 14. For this purpose, the steering mechanism 20 comprises a steering actuator 24 and a wheel connection element 26 coupled to the steering actuator 24.

[0030] The steering actuator 24 is arranged in the steering mechanism housing 66 for axial movement and, in the present case, is designed, in particular, as a rack. The steering actuator 24 has a coupling section 32, which provides an adjustment path for changing the steering angle of the vehicle wheel 14. The coupling section 32 is designed as a toothed section. In principle, however, a coupling section could also be designed as a threaded section. In the present case, a maximum adjustment path of the coupling section 32 is greater than the total adjustment path required to change the steering angle of the vehicle wheel 14 during operation of the vehicle 18.The coupling section 32 comprises an adjustment range 34 and two adjustment ranges 36, 38 adjacent to the adjustment range 34, wherein a first adjustment range 36 is arranged on a side of the adjustment range 34 facing away from the vehicle wheel 14 and a second adjustment range 38 is arranged on a side of the adjustment range 34 facing the vehicle wheel 14. The adjustment range 34 provides a nominally required adjustment travel for changing the wheel steering angle of the vehicle wheel 14, while the adjustment ranges 36, 38 provide an additional adjustment travel as a lead for setting and / or readjusting the track of the vehicle wheel 14. A ratio between a longitudinal extent and / or an axial length of the adjustment ranges 36, 38 and a longitudinal extent and / or an axial length of the adjustment range 34 is between 0.01 and 0.05.Accordingly, the adjustment range 34 defines a nominally required actuator stroke, which can be, for example, in the range between + / -75 mm, while the adjustment ranges 36, 38 define a small additional actuator stroke, which can be, for example, in the range between + / -0.75 mm and + / -3.75 mm. In a normal operating state and / or in a normal driving state, a required adjustment path for changing the wheel steering angle of the vehicle wheel 14 is determined from the adjustment range 34 or from a part of the adjustment range 34 and a part of the first adjustment range 36 or the second adjustment range 38, so that in the normal operating state and / or in a normal driving state only a partial range of the coupling section 32 is used to change the wheel steering angle of the vehicle wheel 14.

[0031] The wheel connection element 26 is arranged in an axial end region of the steering actuating element 24 and, in this case, is designed in particular as a joint head. For fastening the wheel connection element 26 to the steering actuating element 24, the wheel connection element 26 comprises a fastening section 44 which extends in the axial direction. The fastening section 44 is designed in this case as a threaded extension and comprises an external thread which, in the assembled state, is screwed into a threaded bore of the steering actuating element 24. To fix the wheel connection element 26 in its axial position, the steering mechanism 20 also comprises a screw locking element 46 arranged in the axial end region of the steering actuating element 24 and interacting with the fastening section 44, which in this case is designed in particular as a lock nut.

[0032] The steering actuator 28 is coupled to the steering actuator 24, in particular the coupling section 32. The steering actuator 28 is at least partially electrically and / or electronically configured and is provided for actively moving and / or adjusting the steering actuator 24 and consequently for changing a position of the steering actuator 24. For this purpose, the steering actuator 28 comprises at least one electric motor (not shown) and a coupling gear 70 for connecting the electric motor to the steering actuator 24 and in particular the coupling section 32. In the present case, the steering actuator 28 is provided in cooperation with the coupling section 32 for changing the wheel steering angle of the vehicle wheel 14. In principle, it is of course also conceivable to dispense with an additional coupling gear and to couple an electric motor directly to a steering actuator.

[0033] Furthermore, the wheel steering angle adjustment device 10 in the present case comprises a detection sensor system 40 with at least one detection sensor 42 arranged on the steering mechanism 20, advantageously in the form of an inductive sensor. The detection sensor system 40, and in the present case in particular the detection sensor 42, is provided for detecting an axial position of the steering actuating element 24. For this purpose, the detection sensor 42 can interact with a detection contour 72 of the steering actuating element 24, for example in the form of at least one marking, at least one notch, and / or at least one elevation. In the present case, the detection sensor 42 provides a detection signal, for example, when the detection contour 72 of the steering actuating element 24 is at the level of the detection sensor 42, which in this case corresponds to the structural center position of the steering actuating element 24.In principle, however, a position deviating from a center position could also be detected by means of the detection sensor 42. Based on the detection signal or based on the detection signal and at least one control and / or operating variable of the steering actuator 28, such as a rotor position signal, an absolute axial position of the steering actuator 24 can then be determined. Alternatively, a detection sensor system could, of course, also comprise a detection sensor configured to detect multiple axial positions of a steering actuator. Furthermore, a detection sensor system could also comprise multiple detection sensors for detecting multiple axial positions of a steering actuator.

[0034] In certain situations, an unintentional adjustment of the track of the vehicle wheel 14 (or, analogously, the other vehicle wheel 16) may occur. Such an adjustment can occur gradually, for example, due to wear on the rubber bearings of the steering system 54 and / or due to minor accident damage, such as when steering against a curb. However, if the track deviates from an initial factory setting and / or factory specification, this can lead to increased wear and / or damage to the vehicle wheels 14, 16 or the steering system 54.

[0035] By means of the wheel steering angle adjustment device 10, the track of the vehicle wheel 14 can now be adjusted and / or readjusted particularly flexibly and efficiently. The wheel connection element 26 is provided here for the rough adjustment of the track of the vehicle wheel 14, while the steering actuator 28, in cooperation with the coupling section 32, serves for the fine adjustment of the track of the vehicle wheel 14.

[0036] The rough adjustment of the track of the vehicle wheel 14 is performed by adjusting an axial position of the wheel connection element 26 and manually, in particular by hand, by rotating the wheel connection element 26. In the present case, an axial position of the wheel connection element 26 relative to the steering actuator 24 is adjusted by manually rotating the wheel connection element 26, wherein the wheel connection element 26 can be fixed in several different axial positions. The wheel connection element 26 can be fixed by means of the screw locking element 46 such that the track of the vehicle wheel 14 can be adjusted in 0.75 mm increments (racing rod end) or in 1.5 mm increments (conventional rod end), depending on the wheel connection element 26 used.Such a rough adjustment of the track of the vehicle wheel 14 can be carried out, for example, during an initial adjustment of the track of the vehicle wheel 14 and / or during a readjustment of the track of the vehicle wheel 14 in a workshop.

[0037] The fine adjustment of the track of the vehicle wheel 14 is carried out by adjusting an axial position of the steering actuating element 24 and by controlling the steering actuator 28 or automatically by the steering actuator 28. In the present case, an adjustment range of the coupling section 32 used to change the wheel steering angle of the vehicle wheel 14 is adjusted by varying an operating position and / or rest position and consequently an axial position of the steering actuating element 24 using the steering actuator 28. In the present case, in particular the first adjustment range 36 and / or the second adjustment range 38 are used to adjust the used adjustment range. In addition, the steering actuator 28 is provided to take into account and / or use the detection signal of the detection sensor system 40 when finely adjusting the track of the vehicle wheel 14.The detection signal can be used, in particular, to determine an absolute axial position of the steering actuator 24, for example, by means of an initialization during a system start-up of the vehicle 14 and / or the steering system 54. The absolute axial position can be transmitted, for example, to an axle measuring system 52, preferably designed separately or separately from the vehicle 18, which interacts with the steering actuator 28 to adjust the toe of the vehicle wheel 14. As a result, the axle measuring system 52 used only needs to detect a 0° mark of the toe angle of the vehicle wheel 14, while measuring the toe angle across an entire actuator range can be omitted. In principle, however, a corresponding axle measuring system could also be integrated into a vehicle. Furthermore, it is conceivable to fully integrate the functionality of an axle measuring system into a steering actuator.Such a fine adjustment of the track of the vehicle wheel 14 can be carried out, on the one hand, during an initial adjustment of the track of the vehicle wheel 14 and / or during a readjustment of the track of the vehicle wheel 14 in a workshop and, on the other hand, during operation of the vehicle 18, in particular during driving or while driving.

[0038] In Fig. Figure 3 shows an exemplary flowchart with main process steps of a method for adjusting the track of the vehicle wheel 14 using the wheel steering angle adjustment device 10. The method is used in particular for the initial adjustment of the track of the vehicle wheel 14 or for readjusting the track of the vehicle wheel 14 in a workshop. The method described below refers, by way of example, to the wheel steering angle adjuster 48 or the wheel steering angle adjustment device 10 and the vehicle wheel 14. However, the following description can in principle also be applied to the additional wheel steering angle adjuster 50 or the additional wheel steering angle adjustment device 12 and the additional vehicle wheel 16.

[0039] In the present case, in a method step 80, a rough adjustment of the track of the vehicle wheel 14 takes place by adjusting an axial position of the wheel connection element 26. For this purpose, an axial position of the wheel connection element 26 relative to the steering actuating element 24 is adjusted by a manual, in particular manual, rotation of the wheel connection element 26 and fixed by means of the securing element 46.

[0040] In a method step 82, a fine adjustment of the track of the vehicle wheel 14 takes place by adjusting an axial position of the steering actuating element 24. The fine adjustment of the track of the vehicle wheel 14 takes place automatically, in particular by controlling the steering actuator 28 by means of the computing unit 64. To control the wheel steering angle adjusting device 10, the computing unit 64 has a computer program with corresponding program code means. In the present case, for the fine adjustment of the track of the vehicle wheel 14, an adjustment path of the coupling section 32 used to change the wheel steering angle of the vehicle wheel 14 is adjusted by varying an operating position and / or rest position of the steering actuating element 24 by means of the steering actuator 28.For this purpose, an absolute axial position of the steering actuator 24 is determined using a detection signal from the detection sensor system 40 and at least one control and / or operating variable of the steering actuator 28 and transmitted to the axle measuring system 52, which interacts with the steering actuator 28 to adjust the track of the vehicle wheel 14. In principle, however, such an axle measuring system could also be dispensed with.

[0041] In Fig. 4 shows a further flowchart with main method steps of a method for adjusting the track of the vehicle wheel 14 using the wheel steering angle adjustment device 10. The method serves in particular for adjusting the track of the vehicle wheel 14 during operation, in particular while driving, of the vehicle 18. In the present case, the computing unit 64 is further provided to execute the method by controlling the corresponding wheel steering angle adjustment device 10, 12 and, for this purpose, has, in particular, a computer program with corresponding program code means. Furthermore, the method described below again relates, by way of example, to the wheel steering angle adjuster 48 or the wheel steering angle adjustment device 10 and the vehicle wheel 14. However, the following description can in principle also be applied to the further wheel steering angle adjuster 50 or the further wheel steering angle adjustment device 12 and the further vehicle wheel 16.

[0042] In a method step 90, a current track, in particular a current toe-in angle, of the vehicle wheel 14 is determined. For this purpose, at least one operating variable of the steering actuator 28, in particular assigned to the vehicle wheel 14, is determined while the vehicle 18 is driving and compared with at least one reference variable. In this case, an engine torque of the steering actuator 28 is determined and used as the operating variable. The operating variable can, for example, be detected by the internal vehicle sensors or retrieved from the control unit 62. A previously applied factory setting for the operating variable and / or a further operating variable equivalent to the operating variable of the further steering actuator 30, in particular assigned to the further vehicle wheel 16, can be used as the reference variable.Alternatively or additionally, a drive torque of a vehicle wheel can also be used as a reference value.

[0043] The operating variable is preferably determined while the vehicle 18 is traveling straight ahead and advantageously during autonomous and / or automated driving, for example while traveling on a highway using a highway assistance function. By specifying a corresponding target trajectory, particularly precise straight-ahead driving of the vehicle 18 and thus particularly precise determination of the operating variable can be achieved. In principle, however, it is also conceivable to determine a corresponding operating variable during manual driving and / or during defined cornering, for example when driving through a long curve. In the present case, however, the motor torque of the steering actuator 28 is used as the operating variable, which is required to set and / or maintain the, in particular axial, position of the steering actuating element 24 while the vehicle 18 is traveling straight ahead.

[0044] Furthermore, the operating variable is compared with the at least one reference variable in order to determine whether the operating variable deviates from the at least one reference variable.

[0045] If this is the case, in a method step 92 for adjusting the track of the vehicle wheel 14, an adjustment range of the coupling section 32 used to change the wheel steering angle of the vehicle wheel 14 is adjusted by varying an operating position and / or rest position of the steering actuator 24 by means of the steering actuator 28 or by controlling the steering actuator 28. In the present case, in particular, the first adjustment range 36 and / or the second adjustment range 38 are used to adjust the adjustment range used.Consequently, in a first operating state, in particular prior to the adjustment of the track of the vehicle wheel 14, a first partial region of the coupling section 32 is used, and in a second operating state, in particular after the adjustment of the track of the vehicle wheel 14, a second partial region of the coupling section 32 which at least partially deviates from and / or is different from the first partial region is used to change the wheel steering angle of the vehicle wheel 14.

[0046] In addition, in at least one operating state in which the maximum adjustment travel is insufficient for adjusting the track of the vehicle wheel 14, that is to say in an operating state in which the first adjustment range 36 or the second adjustment range 38 is insufficient or exhausted, an information message is generated to indicate to an occupant of the vehicle 18 and / or an owner of the vehicle 18 that a workshop must be visited to adjust the track of the vehicle wheel 14.

[0047] The flow charts in the Fig. 3 and Fig. 4 are intended to describe only exemplary procedures.

Claims

[1] Wheel steering angle adjusting device (10, 12) for changing a wheel steering angle of at least one vehicle wheel (14, 16) of a vehicle (18), with a steering mechanism (20, 22) which comprises a movably mounted steering adjusting element (24) and at least one wheel connection element (26) arranged in an axial end region of the steering adjusting element (24), and with a steering actuator (28, 30) which is provided for changing a position of the steering adjusting element (24) in order to change the wheel steering angle of the vehicle wheel (14, 16), wherein the steering adjusting element (24) has a coupling section (32) for coupling to the steering actuator (28, 30), which defines a maximum adjustment path which is greater than an adjustment path required to change the wheel steering angle of the vehicle wheel (14, 16), and wherein the steering actuator (28, 30) in cooperation with the coupling section (32) for fine adjustment of a track of the vehicle wheel (14,16) and the wheel connection element (26) is provided for coarse adjustment of the track of the vehicle wheel (14, 16). [2] Wheel steering angle adjusting device (10, 12) according to claim 1, characterized by in that the coupling section (32) comprises an adjustment range (34) and at least one adjustment range (36, 38) adjacent to the adjustment range (34), wherein the adjustment range (34) provides a nominally required adjustment path for changing the wheel steering angle of the vehicle wheel (14, 16) and the adjustment range (36, 38) provides an additional adjustment path as a lead for setting and / or readjusting the track of the vehicle wheel (14, 16). [3] Wheel steering angle adjusting device (10, 12) according to claim 2, characterized by that a ratio between a longitudinal extent and / or an axial length of the adjustment range (36, 38) and a longitudinal extent and / or an axial length of the adjustment range (34) is between 0.01 and 0.

05. [4] Wheel steering angle adjusting device (10, 12) according to one of the preceding claims, characterized by that the fine adjustment of the track of the vehicle wheel (14, 16) is carried out by setting an axial position of the steering actuating element (24) and by controlling the steering actuator (28, 30) and / or automatically by the steering actuator (28, 30). [5] Wheel steering angle adjusting device (10, 12) according to one of the preceding claims, characterized by a detection sensor system (40) which comprises at least one detection sensor (42) arranged on the steering mechanism (20, 22) for detecting at least one axial position of the steering actuating element (24), wherein the steering actuator (28, 30) is provided to take into account at least one detection signal of the detection sensor system (40) during the fine adjustment of the track of the vehicle wheel (14, 16). [6] Wheel steering angle adjusting device (10, 12) according to one of the preceding claims, characterized bythat the wheel connection element (26) is fastened to the steering actuating element (24) in an assembled state and can be fixed in several axial positions for coarse adjustment of the track of the vehicle wheel (14, 16). [7] Wheel steering angle adjusting device (10, 12) according to claim 6, characterized by that the wheel connection element (26) for fastening to the steering actuating element (24) comprises a fastening section (44) with an external thread and the steering mechanism (20, 22) for fixing the wheel connection element (26) comprises at least one screw locking element (46) arranged in the axial end region of the steering actuating element (24). [8] Wheel steering angle adjusting device (10, 12) according to one of the preceding claims, characterized by that the rough adjustment of the track of the vehicle wheel (14, 16) is carried out by setting an axial position of the wheel connection element (26) and manually by rotating the wheel connection element (26). [9] Wheel steering angle adjuster (48, 50) with at least one wheel steering angle adjusting device (10, 12) according to one of the preceding claims. [10] Vehicle (18) with at least two steerable vehicle wheels (14, 16) and with at least two wheel steering angle adjusters (48, 50) according to claim 9, wherein each of the steerable vehicle wheels (14, 16) is assigned one of the wheel steering angle adjusters (48, 50). [11] Method for adjusting a track of at least one vehicle wheel (14, 16) of a vehicle (18) by means of a wheel steering angle adjusting device (10, 12) according to one of claims 1 to 8, wherein in a first method step a rough adjustment of the track of the vehicle wheel (14, 16) is carried out by adjusting an axial position of a wheel connection element (26) and in a second method step a fine adjustment of the track of the vehicle wheel (14, 16) is carried out by adjusting an axial position of a steering actuating element (24), wherein for the fine adjustment of the track of the vehicle wheel (14, 16) an adjustment path of a coupling section (32) used to change the wheel steering angle of the vehicle wheel (14, 16) is adapted by varying an operating position and / or rest position of the steering actuating element (24) by means of a steering actuator (28, 30). [12] Method according to claim 11, characterized byin that in the second method step, an axial absolute position of the steering actuating element (24) is determined using a detection signal of a detection sensor system (40) and at least one control and / or operating variable of the steering actuator (28, 30) and is transmitted to the steering actuator (28, 30) and / or to an axle measuring system (52) for adjusting the track of the vehicle wheel (14, 16). [13] Method for adjusting a track of at least one vehicle wheel (14, 16) of a vehicle (18) by means of a wheel steering angle adjusting device (10, 12) according to one of claims 1 to 8, wherein at least one operating variable of a steering actuator (28, 30) is determined and compared with at least one reference variable, and wherein in the event of a deviation of the operating variable from the at least one reference variable for adjusting the track of the vehicle wheel (14, 16), an actuating path of a coupling section (32) used to change the wheel steering angle of the vehicle wheel (14, 16) is adapted by varying an operating position and / or rest position of a steering actuating element (24) by means of the steering actuator (28, 30).

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