Self-centering mechanism and handwheel actuator for a steer-by-wire system

Abstract

A self-aligning mechanism for a steer-by-wire system comprises a steering wheel assembly connected to a steering column shaft with a rotation limit of less than 180° in a first direction and a second direction of rotation from an assembly center position. The mechanism also includes a guide profile mounted on the longitudinal column shaft and a restoring force mechanism designed to generate a restoring force against the guide profile as the steering wheel assembly rotates away from the center position. The self-aligning mechanism improves steering control and safety in steer-by-wire systems.

Description

Area

[0001] The technology relates to the field of automotive engineering, specifically steering systems for vehicles and in particular steer-by-wire systems. background

[0002] Steer-by-wire systems have been developed as an alternative to conventional mechanical longitudinal steering systems in vehicles. In a conventional mechanical steering system, the steering wheel is directly connected to the wheels via a series of mechanical links, allowing the driver to control the vehicle's direction of travel. A characteristic of a mechanical steering system is its natural tendency to be self-centering, meaning that when the driver releases the steering wheel, the vehicle will generally continue to travel straight ahead. This self-centering characteristic is achieved through the design of the wheel suspension and steering system components.

[0003] In contrast, a steer-by-wire system eliminates the mechanical connections between the steering wheel and the vehicle's wheels. Instead, the steering wheel is connected to an electronic control unit (ECU) and a motor, which in turn controls the direction of the wheels. While steer-by-wire systems offer a number of advantages, such as reduced weight and greater design flexibility, they also present challenges in providing the self-centering capability required by law for passenger vehicles.

[0004] Several solutions have been proposed to address the lack of self-centering in steer-by-wire systems. Some of these solutions involve modifying the design of the electronic feedback control system to simulate the self-centering effect. However, these solutions may not be suitable for all types of vehicles and can require complex tuning and calibration processes. Furthermore, in the event of a feedback control failure, there is no natural self-centering mechanism for the steering wheel, as it is not connected to the wheels.

[0005] Therefore, there is a need for an improved self-alignment mechanism for steer-by-wire systems that can provide the required self-centering property. Overview

[0006] In a first aspect, the invention provides a self-aligning mechanism for a steer-by-wire system. The self-aligning mechanism comprises a steering wheel assembly mounted on a steering column shaft, the rotation of which from an assembly center position is limited to less than 180° in a first and a second direction of rotation. The mechanism also includes a geometric shape attached to the steering column shaft and a restoring force mechanism configured to generate a restoring force against the geometric shape when the rotation of the steering wheel assembly increases from the assembly center position.

[0007] In some embodiments, the steering wheel controls have a rotation range limited to between 90° and 150° in the first direction of rotation and in the second direction of rotation from the central position.

[0008] The geometric shape can have the smallest radii at a central position of the geometric shape and increasing radii towards an end position of the geometric shape.

[0009] The geometric shape can also have a symmetrical, arc-shaped guide profile.

[0010] The restoring force mechanism may have a roller bearing designed to move in a direction towards or away from a pivot axis of the steering wheel assembly.

[0011] The roller bearing can be attached to a central guide rod that is fixed to the steering wheel assembly.

[0012] The roller bearing can be selected from the group consisting of a ball bearing, a plain bearing and a tapered roller bearing.

[0013] In some embodiments, the self-aligning mechanism further comprises a pre-tensioned spring designed to exert a torque on the steering wheel assembly towards a central position stop.

[0014] The pre-tensioned spring can be selected from the group consisting of a compression helical spring and a tension helical spring.

[0015] The steering wheel assembly can have at least one spoke that is attached to the steering column shaft.

[0016] At least one spoke may have a central recess that runs along a longitudinal axis of the spoke and is designed to accommodate the restoring force mechanism.

[0017] The central recess of the spoke can be designed to accommodate a roller bearing that moves within the recess along the longitudinal axis of the spoke as the geometric shape moves in relation to the spoke.

[0018] In some embodiments, the geometric shape further includes a central position stop with a central recess designed to accommodate the roller bearing when the steering wheel fitting is in the central position of the fitting.

[0019] The geometric shape can be adapted to different vehicle frames and steering wheel weights and inertias.

[0020] Optionally, the restoring force generated by the restoring force mechanism is constant when the radius of the geometric shape increases from a central position of the geometric shape to an end position of the geometric shape.

[0021] In a second aspect, the invention provides a handwheel actuator that has the self-aligning mechanism described above.

[0022] A third aspect of the invention relates to a method of using the self-aligning mechanism according to the first aspect, wherein the method comprises: a) mounting a steering wheel assembly on the steering column shaft, wherein the steering wheel assembly is rotatable by less than 180° in a first direction and a second direction from an assembly center position, b) mounting a geometric form around the steering column shaft, c) constructing a roller bearing which is functionally wound with a pre-tensioned spring in a guide housing, and d) bringing the roller bearing into contact with the geometric form and generating a self-centering torque when the steering wheel assembly rotates out of the assembly center position. Brief description of the drawings

[0023] The invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 a perspective view of a steering wheel control according to an exemplary embodiment, Fig. 2 a schematic top view of the steering wheel controls in various positions according to an exemplary embodiment, Fig. 3 is a partially cross-sectional view of the self-alignment mechanism in a valve central position according to an exemplary embodiment, Fig. 4 a cross-sectional view of the self-aligning mechanism in another position according to an exemplary embodiment, Fig. 5 a perspective cross-sectional view of the self-alignment mechanism and steering wheel assembly according to an exemplary embodiment, Fig. 6 is a perspective detail view of the self-aligning mechanism according to an exemplary embodiment, Fig. 7 is a perspective detail view of the self-aligning mechanism according to an exemplary embodiment, Fig. Figure 8 shows a perspective detail view of the self-aligning mechanism according to an exemplary embodiment, and Fig. Figure 9 shows a side view of the self-alignment mechanism according to an exemplary embodiment. Detailed description

[0024] The present invention will now be described in detail with reference to various embodiments. It should be understood that these embodiments are presented for illustrative purposes only and are not intended to limit the scope of the present invention.

[0025] Fig. Figure 1 is a perspective view of a handwheel actuator having a steering wheel assembly 10 according to an exemplary embodiment. The steering wheel assembly 10 is mounted on a steering column shaft 30 (preferably in Fig. 5 shown) mounted. Fig. Figure 5 shows a perspective sectional view of the self-aligning mechanism 100 and the steering wheel assembly 10 according to an exemplary embodiment.

[0026] The steering wheel control 10 has a rotation range limited to less than 180° in both directions from a central position. This limited rotation range provides the user with a more controlled and precise steering feel, ensuring that the steering wheel is not over-rotated and does not create potential safety hazards.

[0027] The handwheel actuator comprises a steering wheel assembly 10 with at least one spoke 70 attached to the steering column shaft 30. In some embodiments, the at least one spoke 70 is a single spoke 70 attached to the steering column shaft 30.

[0028] At least one spoke 70 is from a first spoke position B (best in Fig. 2 shown) into a second spoke position C (also best in Fig. (2 shown) rotatable.

[0029] Fig. Figure 2 shows a schematic view of the steering wheel assembly 10. In some embodiments, an electrical component (not shown) optionally projects through the steering wheel assembly 10 and is fixed to the steering column 12. The electrical component (not shown) is positioned outside the range of motion of the at least one spoke 70.

[0030] The range of motion of at least one 70-degree spoke is best in Fig. 2 shown. As mentioned above, at least one spoke 70 can be rotated from a first spoke position B to a second spoke position C. In Fig. 2. The steering wheel control 10 is positioned in a central position. To rotate at least one spoke 70 into the first spoke position B, the steering wheel control 10 is rotated by an angle of X°. To rotate at least one spoke 70 into the second spoke position C, the steering wheel control 10 is rotated by an angle of -X°.

[0031] The steering column 12 serves as the primary structural component, supporting the steering wheel assembly 10 and connecting it to the vehicle. As mentioned above, the steering column 12 has a steering column shaft 30. The steering column shaft 30 is rotatable about a steering column axis AA and is rotatably mounted within the steering column 12. The steering column shaft 30 is functionally connected to the steering actuator and rotates when the steering wheel assembly 10 rotates.

[0032] In some embodiments, the steering column 12 and the steering column shaft 30 are designed to be integrated into steer-by-wire technology. Steer-by-wire technology eliminates the need for a mechanical connection between the steering wheel assembly 10 and the steering mechanism. Instead, the mechanical connection is replaced by an electronic system that transmits steering inputs from the steering wheel assembly 10 to the vehicle's steering mechanism. This electronic system may include various sensors, actuators, and control units that work together to provide precise and responsive steering control.

[0033] The integration of steer-by-wire technology into the steering column 12 and the steering column shaft 30 enables a more compact and lighter design, as well as greater flexibility in the positioning and orientation of the steering wheel controls 10 within the vehicle cabin. Furthermore, the use of electronic components in the steering system enables advanced features and functions, such as a customizable steering feel, adaptive steering assistance, and enhanced safety features.

[0034] In particular, an advantage of a steer-by-wire steering system is that the physical decoupling of the steering wheel assembly 10 from the steering actuator of the steering mechanism means that the steering wheel assembly 10 does not need to be rotated more than 180° in any of its directions of rotation. As described below, the steering wheel assembly 10 only rotates a portion of the rotation in each direction.

[0035] Accordingly, in some embodiments, at least one spoke 70 is rotatable from a first spoke position B to a second spoke position C, and the at least one spoke 70 does not rotate beyond the first spoke position B and the second spoke position C. A stationary area D of the steering wheel actuator is in Fig. 2 shown. At least one spoke 70 is designed in such a way as not to rotate into the stationary area D.

[0036] As in Fig. As shown in Figure 2, the stationary area D is located in the upper part of the steering wheel assembly 10 and the spoke 20 is in a 6 o'clock position when the steering wheel assembly 10 is in its central position. Alternatively, the stationary area D is located in the lower part of the steering wheel assembly 10 and the spoke 70 is in a 12 o'clock position when the steering wheel assembly 10 is in its central position.

[0037] In some embodiments, the steering wheel control 10 can be rotated by less than 180° from a central position into a first direction of rotation and into a second direction of rotation. The first direction of rotation and the second direction of rotation are in Fig. 2 shown with the angular displacement X and -X.

[0038] In some embodiments, the range of motion of the steering wheel control 10 can be between 90° and 150° in the first direction of rotation and between 90° and 150° in the second direction of rotation. In other embodiments, the range of motion of the steering wheel control 10 can be + / - ±90°, ±100°, ±110°, ±120°, ±130°, ±140°, ±150°. As in Fig. As shown in Figure 2, the steering wheel control 10 has an optional range of motion of ±120°. This leaves approximately a 120° segment for the stationary range D of the handwheel actuator. This limitation of the range of motion ensures smooth and consistent movement across the entire range, minimal play or slippage in the movement, low resistance and effort required for operation, adequate tactile feedback for the driver, and reliable and long-lasting operation of the mechanism.

[0039] In other embodiments, the stationary region D comprises a circular sector with an angle of 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145° or 150°.

[0040] In some embodiments, the rotation of the steering wheel controls 10 from the central position in the first and second directions is limited to between 90° and 150°. This specific rotation range allows for a balance between the user's ability to drive sharp turns and the prevention of oversteer, which could lead to a loss of control of the vehicle. The central position of the controls serves as a reference point for the rotation of the steering wheel controls 10, ensuring that the user can easily return the steering wheel controls to their neutral (central) position after driving through a turn.

[0041] In one embodiment, the steering wheel assembly 10 can be rotated in both a first direction of rotation and a second direction of rotation, as indicated by the arrows X, -X in Fig. 2 indicated. This allows the user to steer the vehicle both left and right, providing a versatile and adaptable steering experience. The first and second directions of rotation can be clockwise and counterclockwise, or vice versa, depending on the specific design and orientation of the steering wheel assembly 10 and the steering column shaft 30.

[0042] In some embodiments, the steering wheel assembly 10 has a steering wheel rim 80 with a surface to be gripped by the user.

[0043] In some embodiments, the steering wheel assembly 10 may have a plurality of spokes 70 for improved support and stability.

[0044] In one embodiment, the steering wheel assembly 10 comprises the steering wheel rim 80, which is connected to the steering column shaft 30 via at least one spoke 70. The steering wheel rim 80 is connected to the at least one spoke 70 via at least one outer spoke 14. The outer spoke 14 is connected to an inner ring 16, which is connected to the at least one spoke 70. The steering wheel rim 80 is designed to provide a gripping surface for the driver. The steering wheel rim 80 enables the driver to hold the steering wheel assembly 10 comfortably and securely while driving. The design and features of the steering wheel rim 80 can vary as required. In some embodiments, a steering wheel cover 18 is attached to the inner ring 16. The steering wheel cover 18 is best in Fig. 5 shown.

[0045] The one in the characters, e.g. in Fig. Figure 1 shows a steering wheel rim 80 that is generally circular. The circular shape of the steering wheel assembly 10 is exemplary and not essential for the handwheel actuator. In other embodiments, however, the steering wheel assembly 10 may have other shapes, such as a square, hexagonal, or any other suitable shape. In fact, in some embodiments, the steering wheel assembly 10 may be a yoke-type steering wheel assembly 10.

[0046] To enable the steering wheel control 10 to return to a central position, the handwheel actuator has a self-aligning mechanism 100. The self-aligning mechanism 100 is in Fig. 3 shown. Fig. Figure 3 shows a cross-sectional view of the self-aligning mechanism 100 in the valve's central position.

[0047] In one embodiment, the self-aligning mechanism 100 has a geometric shape 22. The geometric shape is mounted around the longitudinal column shaft 30 and is designed to interact with the restoring force mechanism 180 to generate a restoring force against the geometric shape 20. This restoring force is generated as the steering wheel assembly 10 rotates from its central position. In this way, the self-aligning mechanism 100 exerts a self-centering torque on the steering wheel assembly 10. The geometric shape 20 is a component mounted relative to the steering wheel assembly 10, having a surface of varying height, and the restoring force mechanism 180 rests against this surface. The geometric shape 20 can also be considered a guide profile 22.

[0048] The geometric shape 20 is fixed with respect to the longitudinal column axis AA. Accordingly, the geometric shape 20 does not rotate when the longitudinal column shaft 30 and the steering wheel assembly 10 are rotated.

[0049] In some embodiments, the geometric shape 20 has a minimum radius at its central position 110 and a radius that increases towards its end position 120. This design enables a smooth and continuous generation of the restoring force as the steering wheel assembly 10 rotates away from its central position. The fact that the radius is smallest at the central position 110 ensures that the restoring force becomes minimal as the steering wheel assembly 10 approaches its central position, resulting in a stable and comfortable resting position of the steering wheel.

[0050] In one embodiment, the geometric shape 20 can have a symmetrical, arcuate guide profile 22 extending from the central position 110 of the geometric shape to the end position 120. This symmetrical, arcuate guide profile 22 ensures that the restoring force generated by the restoring force mechanism 180 is uniform and predictable in both the first and second directions of rotation. This uniformity of the restoring force provides the driver with an intuitive and natural steering feel.

[0051] In some embodiments, the geometric shape 20 is designed with a spiral cross-section that changes in radius from the central position 110 of the geometric shape to the end position 120. This variation in radius enables a continuous and smooth generation of the restoring force as the steering wheel assembly 10 rotates out of its central position. The symmetrical, arc-shaped guide profile 22 ensures that the restoring force is uniform and predictable in both directions of rotation, providing the driver with a more intuitive and natural steering feel.

[0052] The geometric shape 20 can be attached around the steering column shaft 30 using various methods. In some embodiments, the geometric shape 20 can be attached in relation to the steering column 12, but it must be ensured that the geometric shape 20 remains stationary when the steering wheel assembly 10 rotates about the steering column axis AA.

[0053] The geometric shape 20 and its mounting configuration relative to the steering column shaft 30 offer numerous advantages for the self-aligning mechanism 100 in a steer-by-wire system. The geometric shape 20 enables a smooth and continuous generation of the return force as the steering wheel assembly 10 rotates out of its center position. The fixed mounting of the geometric shape 20 relative to the steering column shaft 30 ensures that the return force is consistent and predictable across the entire rotation range of the steering wheel assembly 10, further enhancing steering feel. Furthermore, the geometric shape 20 can be adapted to different vehicle frames, steering wheel weights, and steering wheel inertias, allowing for individual customization and optimization of the self-aligning mechanism 100 for various vehicle applications.

[0054] As mentioned above, the self-aligning mechanism 100 for a steer-by-wire system includes a restoring force mechanism 180, which is designed to generate a restoring force acting against the geometric shape 20. The restoring force is generated as the steering wheel assembly 10 is rotated from its center position, resulting in a self-centering torque on the steering wheel assembly 10 and ensuring that the steering wheel returns to its center position when not in use or when the user releases the steering wheel. The restoring force mechanism 180 is designed to press against the guide profile 22 to generate a restoring force on the steering wheel assembly 10. This means that the steering wheel assembly 10 returns to a center position as a result of the restoring force mechanism 180 exerting force on the guide profile 22.

[0055] In one embodiment, the restoring force mechanism 180 has a roller bearing 50 which is designed to rotate in a direction E (as in Fig. (3 shown) towards or away from the steering column axis AA. The roller bearing 50 is in contact with the profile 22 of the geometric shape 20 and rolls along it. The movement of the roller bearing 50 is determined by the varying radii of the geometric shape 20 as the steering wheel assembly 10 is rotated. This movement of the roller bearing 50 generates the restoring force against the geometric shape 20, which in turn generates a self-centering torque on the steering wheel assembly 10.

[0056] Fig. Figure 4 shows the same structure as in Fig. Figure 3 shows, except that the steering wheel assembly 10 has been rotated with respect to the steering column axis AA. In this case, the roller bearing 50 has been pressed against the restoring force mechanism 180, which generates a restoring force on the geometric shape 20.

[0057] In some embodiments, the roller bearing 50 can be replaced by another suitable bearing. For example, the roller bearing 50 can be replaced by one or more ball bearings, plain bearings, or tapered roller bearings. Each of these bearing types offers various advantages in terms of load capacity, friction, and durability, allowing the self-aligning mechanism 100 to be customized to meet the specific requirements of the steer-by-wire system and the vehicle in which it is installed. In some embodiments, the roller bearing 50 is optionally omitted, and an end surface of the restoring force mechanism 180 is in contact with and presses against the guide profile 22. In some embodiments, the end surface can have a low-friction coating.

[0058] In one embodiment, the roller bearing 50 can be mounted on a guide housing 140, which is attached to the steering column assembly 10. The guide housing 140 is designed to keep a pre-tensioned spring 60 and the roller bearing 50 in line with the steering column axis AA, ensuring that the return force mechanism 180 operates smoothly and efficiently. In some embodiments, the guide housing 140 is formed as a single unit with the spoke 70.

[0059] In some other embodiments, the guide housing 140 is separate from the spoke 70. For example, in Fig. As shown in Figures 6 to 9, the guide housing 140 and the self-aligning mechanism 100 can optionally accommodate the return force mechanism 180 separately from the spoke 70. This configuration can offer additional design flexibility and simplify the assembly process.

[0060] In one embodiment, the return force mechanism 180 can include a pre-tensioned spring 60 configured to generate a torque on the steering wheel assembly 10 towards a center position stop 40. The pre-tensioned spring 60 interacts with the roller bearing 50 to generate a self-centering torque, ensuring that the steering wheel assembly 10 returns to its center position when not in use or when released by the user. This feature is particularly important in the event of a feedback control failure, as it provides a fail-safe mechanism for maintaining vehicle stability and steering.

[0061] In some embodiments, the preloaded spring 60 can be a helical compression spring or a helical extension spring. Alternatively, any other suitable spring type can be used for the preloaded spring 60. Both types of springs offer different advantages in terms of load capacity, spring characteristic, and durability, which makes it possible to customize the self-aligning mechanism 100 to meet the specific requirements of the steer-by-wire system and the vehicle in which it is installed. The choice of spring type may also depend on the design of the steering wheel assembly 10 and its geometric shape 20, as well as on the desired strength of the self-centering torque and the overall performance characteristics of the steer-by-wire system. In some examples, a preloaded spring 60 is not used. Instead, another component can be used to press the return force mechanism 180 against the guide profile, e.g., a spring.a rubber block, a pneumatic cylinder piston, etc. In some embodiments, the pre-tensioned spring 60 is not pre-tensioned and the spring is only tensioned when the steering wheel assembly 10 rotates.

[0062] As in Fig. 3, Fig. 4 and Fig. As shown in Figure 5, in some embodiments, at least one spoke 70 can have a central spoke recess 160 extending along the longitudinal axis 170 of the spoke. The central spoke recess 160 can be designed to accommodate the return force mechanism 180, which includes the roller bearing 50 and the pre-tensioned spring 60. By accommodating the return force mechanism 180 within the central spoke recess 160, the overall design of the steering wheel assembly 10 can be more compact and streamlined, thus reducing the overall size and weight of the self-aligning mechanism 100.

[0063] The central spoke recess 160 can also protect the return force mechanism 180 from external contaminants such as dust, dirt, and moisture, which could interfere with its proper functioning. Furthermore, the central spoke recess 160 can help reduce noise generated by the return force mechanism 180 during operation, providing the user with a quieter and more comfortable riding experience.

[0064] In some embodiments, the central spoke recess 160 is designed to accommodate a roller bearing 50, which moves within the recess along the longitudinal axis of the spoke 170 when the geometric shape 20 moves relative to the spoke 70. This movement is described in the Fig. 3 and Fig. Figure 4 illustrates this movement of the roller bearing 50 within the central spoke recess 160, enabling the generation of the restoring force against the geometric shape 20 while the steering wheel assembly 10 rotates in the first direction of rotation or in the second direction of rotation.

[0065] The mobility of the roller bearing 50 within the central spoke recess 160 can be facilitated by a low-friction surface or by a lubricant introduced into the interior of the central spoke recess 160. This can help ensure smooth and uniform movement of the roller bearing 50 within the central spoke recess 160, providing a reliable and predictable self-centering force for the steering wheel assembly 10.

[0066] In some embodiments, the geometric shape 20 of the self-aligning mechanism 100 may include a center position stop 40 designed to provide a reference point for the steering wheel controls 10 when they are in the center position. The center position stop 40 may be an integral part of the geometric shape 20 or a separate component that is connected to or interacts with it. The center position stop 40 can provide a stable and reliable reference point for the steering wheel controls 10 to return to their center position, thus ensuring proper alignment and control of the steer-by-wire system.

[0067] In some embodiments, the center position stop 40 can have a central recess 130 formed by the two intersecting, symmetrical parts of the geometric shape 20. This creates a central recess 130 that provides positive feedback to the user when the steering wheel controls 10 are in the center position. The central recess 130 is designed to accommodate the roller bearing 50 when the steering wheel controls 10 reach the center position. The central recess 130 is designed to receive the roller bearing 50, allowing it to move smoothly into the recess when the steering wheel controls 10 are rotated and the geometric shape 20 moves relative to the spoke 70.

[0068] The engagement of the roller bearing 50 in the central recess 130 at the instrument's center position ensures that the restoring force mechanism 180 generates the minimum restoring force against the geometric shape 20, thus providing a stable and consistent reference point for the steering wheel instrument 10. This engagement also contributes to the self-centering overall torque generated by the self-aligning mechanism 100 when the restoring force against the geometric shape 20 is generated as the steering wheel instrument 10 rotates from the instrument's center position.

[0069] The central recess 130 can be designed with a special shape and size to accommodate various types of roller bearings 50, such as ball bearings, plain bearings, and tapered roller bearings. This design flexibility allows the self-aligning mechanism 100 to be adapted to different steering systems and vehicle frames, providing a versatile solution for generating self-centering torque in a steer-by-wire system.

[0070] In some embodiments, the geometric shape 20 can be adapted to different vehicle frames and steering wheel weights / inertias, allowing the self-aligning mechanism 100 to be individually adapted to specific vehicle requirements. This adaptability ensures that the self-aligning mechanism 100 provides an optimal self-centering torque for a given vehicle, thus improving the overall steering feel for the driver.

[0071] In some embodiments, the geometric shape 20 of the self-aligning mechanism 100 can be designed and configured to adapt to different vehicle frames and steering wheel weights / inertias. This adaptability allows the self-aligning mechanism 100 to be adaptable and versatile, enabling optimal performance and self-centering torque over a wide range of vehicle types and steering wheel designs.

[0072] In some embodiments, the geometric shape 20 can be designed with varying radii and arcuate guide profiles 22 to accommodate requirements regarding different vehicle frames and steering wheel weight / inertia. The geometric shape 20 can be designed to have a smallest radius at the central position 110 of the geometric shape and increasing radii towards the end positions 120, as previously described. The specific radius values ​​and the rate at which the radii increase towards the end position 120 of the geometric shape can be set and optimized for different vehicle frames and steering wheel weights / inertias.

[0073] In some embodiments, the return force mechanism 180 can be adjusted to provide an appropriate return force for different vehicle frames and steering wheel weights / inertias. This may involve selecting different types of roller bearings 50, such as ball bearings, plain bearings, or tapered roller bearings, as well as adjusting the preload spring 60. The preload spring may be selected from a group consisting of helical compression springs and helical extension springs, with different spring characteristics and preload values, to generate the desired self-centering torque for the specific vehicle frame and steering wheel weight / inertia.

[0074] In some embodiments, the pre-tensioned spring 60 can have a linear spring characteristic. This means that the generated restoring force depends on the degree of compression of the pre-tensioned spring 60. If the profile 22 of the geometric shape 20 increases linearly as a function of the change in angle, then the restoring force is constant when the steering wheel assembly 10 is rotated relative to the geometric shape 20. In some embodiments, the restoring force exerted by the restoring force mechanism 180 is not constant. For example, the restoring force increases with increasing rotation of the steering wheel assembly 10 from the center position. In this case, the pre-tensioned spring 60 can have a non-linear spring characteristic. For example, the restoring force generated at a small deflection of the roller bearing 50 is less than the restoring force generated at a large deflection of the roller bearing 50.

[0075] In some other embodiments, the restoring force generated by the restoring force mechanism 180 can be adjusted by the profile 22 of the geometric shape 20. For example, the radius of the profile 22 may not increase linearly as a function of the angular deflection. This means that the roller bearing 50 and the pre-tensioned spring 60 are compressed at different rates depending on the position of the steering wheel assembly 10 relative to the geometric shape 20. The profile 22 of the geometric shape 20 can be adjusted as described below.

[0076] The adaptability of the geometric shape 20 and the return force mechanism 180 offers several advantages for the self-aligning mechanism 100 in a steer-by-wire system. Firstly, it allows the self-aligning mechanism 100 to be adapted across a wide range of vehicle types and steering wheel designs, ensuring optimal performance and self-centering torque for each specific application. This adaptability can lead to improved steering feel and driver confidence, as well as increased safety and reliability in the event of a feedback control failure.

[0077] Secondly, the adaptable geometric shape 20 and the adaptable restoring force mechanism 180 can help reduce the overall complexity and cost of the steer-by-wire system by enabling the use of a single self-aligning mechanism 100 design for many vehicle platforms and steering wheel designs. This can lead to economies of scale and reduced manufacturing costs, as well as simplified inventory management and warehousing for vehicle manufacturers and service providers.

[0078] In summary, the adaptability of the geometric shape 20 and the return force mechanism 180 in the self-aligning mechanism 100 for a steer-by-wire system offers a versatile and adaptable solution for generating self-centering torque across a wide range of vehicle frames and steering wheel weights and inertias. This adaptability ensures optimal performance, improved steering feel, and increased safety and reliability for various vehicle types and steering wheel designs, while also reducing complexity and costs for vehicle manufacturers and service providers.

[0079] It will now be referred to as Fig. 6, Fig. 7, Fig. 8 and Fig. 9. Referenced. Fig. Figure 6 is an enlarged perspective view of the self-aligning mechanism 100 according to one embodiment. Fig. Figure 7 is an enlarged perspective view of the self-aligning mechanism 100 according to an exemplary embodiment. Fig. Figure 8 is an enlarged perspective view of the self-aligning mechanism 100 according to one embodiment. Fig. Figure 9 is a side view of the self-aligning mechanism 100 according to an exemplary embodiment.

[0080] The self-aligning mechanism 100 is the same as that shown in the preceding figures, except that the self-aligning mechanism 100 is not part of the spoke 70. Instead, the self-aligning mechanism 100 is mounted on the steering wheel assembly 10.

[0081] Fig. Figure 6 shows a portion of the outer spoke 14 of the steering wheel assembly 10. The guide housing 140 is mounted on the steering wheel assembly 10. The guide housing 140 includes a geometric form slot 190, which is designed to accommodate the geometric form 20 when the steering wheel assembly 10 and the guide housing 140 rotate with respect to the geometric form 20. Similar to the preceding embodiments, the geometric form 20 is fixed with respect to the longitudinal column axis AA.

[0082] Fig. 7 and Fig. Figure 8 shows the self-alignment mechanism 100 mounted on the steering wheel fitting 10. Fig. Figure 7 shows a partial sectional view of the guide housing 140. The restoring force mechanism 180 is visible here. The restoring force mechanism 180 functions in the same way as previously discussed.

[0083] In some embodiments, the roller bearing 50 is rotatably mounted on a movable carriage 200. The movable carriage 200 is designed to slide within the guide housing 140 when the geometric shape 20 enters the geometric shape slot 190 and the profile 22 of the geometric shape 20 comes into contact with the roller bearing 50.

[0084] When the user releases the steering wheel control 10, the tensioned spring 60 becomes effective via the roller bearing 50, generating a restoring torque that returns the steering wheel control 10 to the center position of the control.

[0085] The precise shape of the profile 22 is, in some embodiments, designed to ensure predictable and reliable restoring force behavior. The steering wheel assembly 10 is controlled by a motor and an electronic control unit when functioning normally. However, in the event of a malfunction, the self-aligning mechanism 100 provides a physical feedback mechanism.

[0086] In other embodiments, two or more embodiments are combined. Features of one embodiment can be combined with features of other embodiments.

[0087] Exemplary embodiments of the present invention have been described in particular with reference to the illustrated embodiments. However, it should be acknowledged that variations and modifications of the described embodiments are possible within the scope of the invention.

Claims

[1] Self-alignment mechanism (100) for a steer-by-wire system with: a steering wheel instrument (10) mounted on a steering column shaft (30) whose rotation from a central instrument position is limited to less than 180° in a first direction of rotation and in a second direction of rotation, wherein the steering wheel instrument (10) has: a guide profile (22) that is mounted around the steering column shaft (30), and a restoring force mechanism (180) designed to exert force on the guide profile (22) in order to generate a restoring force against the guide profile (22) when the rotation of the steering wheel instrument (10) increases from the instrument's central position. [2] Self-aligning mechanism (100) according to claim 1, wherein the steering wheel assembly (10) has a rotation from the central position limited to between 90° and 150° in the first direction of rotation and the second direction of rotation. [3] Self-aligning mechanism (100) according to claim 1 or 2, wherein the guide profile (22) has a smallest radius in a central position (110) of a geometric shape and radii increasing towards an end position (120) of a geometric shape. [4] Self-aligning mechanism (100) according to one of claims 1 to 3, wherein the guide profile (22) is a symmetrical, arc-shaped guide profile (22). [5] Self-aligning mechanism (100) according to any one of claims 1 to 4, wherein the restoring force mechanism (180) comprises a roller bearing (50) configured to move in a direction towards or away from a pivot axis of the steering wheel assembly (10). [6] Self-aligning mechanism (100) according to claim 5, wherein the roller bearing (50) is attached to a guide housing (140) which is connected to the steering wheel assembly (10). [7] Self-aligning mechanism (100) according to one of claims 5 or 6, wherein the roller bearing (50) is selected from the group consisting of a ball bearing, a plain bearing and a tapered roller bearing. [8] Self-aligning mechanism (100) according to one of claims 1 to 7, which further comprises a pre-tensioned spring (60) designed to generate torque on the steering wheel assembly (10) towards a central position stop (40). [9] Self-aligning mechanism (100) according to claim 8, wherein the pre-tensioned spring (60) is selected from the group consisting of a helical compression spring and a helical extension spring. [10] Self-aligning mechanism (100) according to any one of claims 1 to 9, wherein the steering wheel assembly (10) has at least one spoke (70) attached to the steering column shaft (150). [11] Self-aligning mechanism (100) according to claim 10, wherein the at least one spoke (70) has a central spoke recess (160) which extends along a spoke longitudinal axis (170) and is designed to accommodate the restoring force mechanism (180). [12] Self-aligning mechanism (100) according to claim 11, wherein the central spoke recess (160) is configured to accommodate a roller bearing (50) which moves within the recess along the longitudinal axis (170) of the spoke when the guide profile (22) moves relative to the spoke (70). [13] Self-aligning mechanism (100) according to one of claims 1 to 12, wherein the guide profile (22) further comprises a central position stop (40) with a central recess (130) designed to accommodate the roller bearing (50) when the steering wheel assembly (10) is in the central position of the assembly. [14] Self-aligning mechanism (100) according to any one of claims 1 to 13, wherein the guide profile (22) is interchangeable with another guide profile having a different shape, which is designed for a different vehicle frame and / or a different steering wheel weight / steering wheel inertia. [15] Self-aligning mechanism (100) according to any one of claims 1 to 14, wherein the restoring force generated by the restoring force mechanism (180) is constant while the radius of the guide profile (22) increases from a central position (110) of the geometric shape to an end position (120) of the geometric shape. [16] Handwheel actuator with a self-aligning mechanism (100) according to any one of claims 1 to 15. [17] Method for using the self-aligning mechanism (100) according to any one of claims 1 to 16, in a steer-by-wire system, wherein the method comprises, a) to mount a steering wheel control (10) on the longitudinal column shaft (150), wherein the steering wheel control (10) can be rotated from a central control position by less than 180° in a first direction of rotation and in a second direction of rotation, b) to attach a guide profile (22) around the longitudinal column shaft (150), c) to construct a roller bearing (50) which is functionally coupled to a pre-tensioned spring (60) in a guide housing (140) in the steering wheel assembly (10), and d) to bring the roller bearing (50) into contact with the guide profile (22) and to generate a self-centering torque when the steering wheel assembly (10) is turned out of a central position.

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