Sensor device for a wheel actuator of a steer-by-wire system of a vehicle, wheel actuator, steer-by-wire system, vehicle and method for determining a position of a steering rod of a vehicle

Description

[0001] The invention relates to a sensor device for a wheel actuator of a vehicle's steer-by-wire system. The invention further relates to a corresponding wheel actuator for a vehicle's steer-by-wire system. The invention also relates to a corresponding steer-by-wire system for a vehicle and a corresponding vehicle. Furthermore, the invention relates to a method for determining the position of a vehicle's steering column using a corresponding sensor device.

[0002] Future steer-by-wire steering systems have no mechanical connection between the steering wheel and the steering gear. As a result, the relationship between the steering wheel angle and the steering column position is not fixed and can change during operation. Determining the current steering column position using the steering wheel angle is therefore no longer possible.

[0003] Known sensor systems determine the steering rod position using rotor position information from a motor shaft in a wheel actuator power pack. These systems often utilize multiple sensors mounted on the motor shaft and an auxiliary shaft to calculate the rotor position using the vernier scale principle. Such systems are complex to manufacture and operate. Furthermore, a reliable determination of the steering rod position from a stationary vehicle using rotor position information is not possible, as movement of the steering rod while the wheel actuator is switched off can lead to a loss of steering rod position data.

[0004] Other well-known sensor technologies involve directly measuring the steering column position via a linear sensor. Such sensors are relatively complex, require a large installation space, are sensitive to tolerances, and typically require pre-assembly. Furthermore, a cable must be manually connected in a relatively complex process to ensure sensor data transmission and power supply.

[0005] WO 2020 / 256336 A1 discloses embodiments of a steer-by-wire type steering device which can significantly reduce production costs by reducing the number of components and simplifying the assembly process by omitting a pinion, etc., and by detecting the position of a sliding rod based on rotation information acquired by a gearbox that transmits the rotational force of a motor to the sliding rod.

[0006] The invention is therefore based on the objective of providing an improved sensor device for a wheel actuator of a vehicle's steer-by-wire system. In particular, the invention aims to provide a sensor device for a wheel actuator of a vehicle's steer-by-wire system that enables absolute steering column position determination, even from a stationary vehicle, e.g., during vehicle start-up, that has a simple design, is easy to manufacture and assemble, requires minimal computational effort to operate, and exhibits improved electromagnetic compatibility. Furthermore, the invention aims to provide an improved wheel actuator for a vehicle's steer-by-wire system. Finally, the invention aims to provide an improved steer-by-wire system for a vehicle, as well as a corresponding vehicle.Furthermore, the invention is based on the objective of providing an improved method, particularly with regard to the absolute position determination of the steering rod, for determining the position of the steering rod of a wheel actuator using a corresponding sensor device.

[0007] The problem according to the invention is solved by: a sensor device for a wheel actuator of a steer-by-wire system of a vehicle with the features of the independent device claim, a wheel actuator for a steer-by-wire system of a vehicle with the features of the dependent device claim, a corresponding steer-by-wire system for a vehicle with the features of the independent system claim, a corresponding vehicle with the features of the second dependent device claim and a method for determining a position of the steering rod of a wheel actuator with the features of the independent method claim.

[0008] The invention provides: a sensor device for a component, in particular a longitudinally displaceable component, preferably for a steering rod of a vehicle, wherein the steering rod can be driven by a wheel actuator of a steer-by-wire system of a vehicle, and wherein the wheel actuator is configured to control the steering rod of the vehicle according to a steering request of the steer-by-wire system, the sensor unit comprising: a housing for arranging the sensor device on a transmission unit for driving the component, in particular a transmission unit of the wheel actuator, a sensor unit for determining a position of the component, in particular the steering rod of the vehicle, wherein the sensor unit comprises the following elements: a transmission element for providing a mechanical operative connection to a transmission element of the transmission unit, a signal transmitter which is rotationally fixed to the transmission element, for indicating an angle of the transmission element, wherein the transmission element is designed such that a maximum of one revolution of the transmission element represents a full stroke of the component, in particular the steering rod of the vehicle.

[0009] A wheel actuator within the scope of the invention can comprise a drive unit (so-called powerpack, e.g. including a motor and a control device) and a transmission unit that converts the electrical drive line of the drive unit into the mechanical movement of the steering rod.

[0010] The steering rod is in a mechanical operative connection with the transmission unit, which controls the steering rod according to the steering requirement.

[0011] A wheel actuator within the scope of the invention can, for example, be designed as an electromechanical steering gear, e.g. with the "single-pinion" design.

[0012] The steering rod can, for example, be designed as a rack and pinion that interacts with a corresponding gear element in the transmission unit, such as a pinion, to move the rack. However, the mechanical design of the steering rod and the transmission unit can be implemented in a variety of ways. Rotatable and / or linearly movable steering rods are also conceivable, which, for example, have an external thread and interact with a corresponding gear element in the transmission unit, such as a worm gear and / or a threaded rod, etc., to move the steering rod.

[0013] When the steering rod is moved between its extreme left and extreme right positions, it performs a linear movement. When the steering rod is moved between its extreme left and extreme right positions, this disclosure refers to a full stroke of the steering rod.

[0014] The transmission element is designed in such a way that a maximum of one revolution of the transmission element, meaning a revolution of the transmission element less than or equal to 360°, represents a full stroke of the steering rod of the vehicle, which enables steering between the extreme left position and the extreme right position.

[0015] The invention provides an absolute measuring sensor unit on a gear unit of a wheel actuator, preferably integrated structurally therein. A toothed section can be formed on a corresponding gear element, into which the transmission element, e.g., in the form of a gear, engages. The gear ratio can be selected such that the transmission element rotates a maximum of one revolution over the entire stroke of the steering rod. A signal transmitter, e.g., in the form of a magnet, is connected to this transmission element. The signal transmitter serves to determine the angle of the transmission element. This angle allows for a clear determination of the position of the steering rod (maximum one revolution over a full stroke).

[0016] The sensor device can advantageously be designed such that the transmission element, the signal transmitter, and in particular a circuit board including a signal detector are housed in a casing, e.g., in the form of a cover, e.g., made of plastic, preferably with an integrated connector. The integrated connector facilitates simple wiring of the sensor device. This also reduces the assembly effort of the sensor device, since only one modular, individually handled, and integrated unit is mounted on the gearbox, preferably in a single assembly step.

[0017] The sensor device can advantageously be designed in such a way that the tolerance chains between the signal transmitter and a circuit board are kept low.

[0018] The freedom from play between the transmission element and the gear element can be achieved directly during the assembly of the sensor device.

[0019] The sensor device can advantageously be queried only when starting the vehicle, e.g., when the vehicle begins to move, in order to obtain the initial value for the steering column position. During vehicle operation, the system can switch back to an existing steering column position control system, which can, for example, rely on motor position sensing in the drive unit or the power pack. This can advantageously reduce the requirements for electromagnetic compatibility.

[0020] Different measurement methods can be used to implement angle measurement, e.g. magnetic, inductive, optical, etc.

[0021] Furthermore, the housing can be designed to accommodate the sensor unit with all its components. This allows for the handling of only one modular, individually manageable, and cohesive assembly unit during the installation of the sensor device.

[0022] Furthermore, the housing can be designed to be arranged as a cover on the gear unit of the wheel actuator, thus covering and preferably sealing the sensor unit. This allows for easy assembly of the sensor device, preferably in a single assembly step.

[0023] Furthermore, the housing can be designed such that the sensor device, in the form of a modular, individually handled, and integrated unit, can be attached to the gear unit of the wheel actuator, and / or that the sensor device can be attached to the gear unit of the wheel actuator in a single assembly step. This allows for improved assembly of the sensor device.

[0024] Furthermore, the housing may be made of plastic and / or molded from plastic. This allows for simple manufacturing of the sensor device, even in large quantities.

[0025] Advantageously, the housing can be manufactured as an injection-molded component. This allows for simple production of the sensor device.

[0026] Furthermore, the housing may be designed to include a connector, particularly an overmolded one, and / or a cable tail to provide electrical and / or data connectivity for the sensor unit. This facilitates simple wiring of the sensor device.

[0027] Corresponding to the signal transmitter, the sensor unit can include a signal detector. Furthermore, the sensor unit can include a printed circuit board. Preferably, the signal detector can be arranged on the printed circuit board of the sensor unit. To simplify the assembly of the printed circuit board, the board can be attached to the housing, in particular by means of positioning pins.

[0028] Furthermore, it is conceivable that the sensor unit could have at least one of the following measurement principles: electromechanical, magnetic, inductive, optical, etc.

[0029] In this way, angle measurement can be enabled in a flexible manner.

[0030] To further simplify the manufacturing of the sensor device, the transmission element can be designed as a gear. Furthermore, the transmission element can have a specific gear ratio relative to the gear element of the transmission unit. To move the steering rod through its full stroke, the gear element can rotate multiple times, for example, 2, 3, 4, or more times. The gear ratio between the transmission element and the gear element can then be set to 1:2, 3, 4, or higher. Advantageously, the gear ratio between the transmission element and the gear element can be set as high as possible, for example, at least 1:4, so that the sensor device can be flexibly positioned on different transmission units. In this way, a detected angle of the transmission element can also clearly indicate the position of the steering rod.

[0031] To enable improved angle determination of the transmission element and thus reliable and precise position determination of the steering rod, the transmission element can be adjusted without play on the transmission element of the transmission unit during the mounting of the sensor device on the transmission unit. For this purpose, the sensor device as a whole can be lowered onto the transmission unit from top to bottom and then pressed towards the transmission element to allow for backlash-free engagement of the transmission element with the transmission element of the transmission unit.

[0032] Furthermore, the invention provides: a wheel actuator for a steer-by-wire system of a vehicle, wherein the wheel actuator is configured to control a steering rod of the vehicle according to a steering request of the steer-by-wire system, the wheel actuator comprising: a sensor device for determining the position of the steering rod, which can be designed as described above, and a gearbox unit with a gearbox element for providing a mechanical connection to the steering rod of the vehicle, wherein the transmission element is designed to provide a specific gear ratio to the transmission element, such that at most one revolution of the transmission element represents a full stroke of the vehicle's steering rod.

[0033] Advantageously, the gear element can be designed with teeth to provide the specific gear ratio to the transmission element.

[0034] The same advantages can be achieved with the wheel actuator according to the invention as with the sensor device. These advantages are fully addressed herein.

[0035] Furthermore, the invention provides a steer-by-wire system for a vehicle with a corresponding wheel actuator. The same advantages can be achieved with the steer-by-wire system according to the invention as with the sensor device. These advantages are fully addressed herein.

[0036] Furthermore, the invention provides a vehicle, in particular a highly automated and / or autonomous vehicle, which may not have or need not have a steering wheel, with a corresponding steer-by-wire system. The vehicle according to the invention offers the same advantages as the sensor device. These advantages are fully addressed herein.

[0037] Furthermore, the invention provides: a method for determining the position of a steering rod of a vehicle using a sensor device, which can be designed as described above, in particular when starting a vehicle, comprising: Determining the angle of the transmission element, determining the absolute position of the steering rod using the angle of the transmission element.

[0038] Advantageously, the procedure can be performed when the vehicle is started. A further advantage is that the steering column position can be determined independently of an engine position sensor in a wheel actuator drive unit. Advantageously, the procedure can be terminated and / or the sensor unit switched off after the absolute steering column position has been determined, so that, particularly during normal vehicle operation, an engine position sensor in a wheel actuator drive unit can take over the steering column position determination. In this way, mutual interference between the sensor device and the engine position sensor can be avoided. Thus, the requirements for electromagnetic compatibility of the sensor device and the engine position sensor can be reduced.

[0039] The method according to the invention offers the same advantages as the sensor device. These advantages are fully addressed herein.

[0040] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can be essential to the invention individually or in any combination. It shows: Fig. 1 is an exemplary representation of a wheel actuator in a sectional view perpendicular to a steering rod, Fig. 2 is an enlarged representation of a wheel actuator in a sectional view perpendicular to a steering rod, and Fig. 3 is an exemplary representation of a wheel actuator in a sectional view parallel to a steering rod.

[0041] The Figs. 1 to 3 We show a sensor device 100 for a wheel actuator 200 of a steer-by-wire system S of a vehicle F within the scope of the present disclosure. The wheel actuator 200 within the scope of the present disclosure serves to control a steering rod 101 of the vehicle F according to a steering request of the steer-by-wire system S. The wheel actuator 200 represents a wheel-side component of the steer-by-wire system S.

[0042] The sensor unit 100 has the following elements: a housing 10 for arranging the sensor device 100 on a gear unit 201 of the wheel actuator 200, a sensor unit 20 for determining a position of the steering rod 101, wherein the sensor unit 20 comprises the following elements: a transmission element 21 for providing a mechanical operative connection to a gear element 202 of the gear unit 201, a signal transmitter 22 which is rotationally fixed to the transmission element 21, for indicating an angle of the transmission element 21, wherein the transmission element 21 is designed such that a maximum of one revolution of the transmission element 21 represents a full stroke of the steering rod 101 of the vehicle F.

[0043] As it is Fig. 1As indicated, the wheel actuator 200 can comprise a drive unit 203 (so-called powerpack, e.g., including a motor M with a motor shaft 204 and a control device not shown for the sake of simplicity) and a gear unit 201 (with a worm gear 205, which is rotationally fixed to the gear element 202). The steering rod 101 is mechanically connected to the gear unit 201 via the gear element 202 in order to control the steering rod 101 according to the steering requirements. The drive unit 203 supplies the electrical power for this purpose.

[0044] A wheel actuator 200 within the scope of the invention can preferably be designed as an electromechanical steering gear, e.g. with the design "Single-Pinion".

[0045] However, the mechanical design of the steering rod 101 and the gearbox unit 201 can be implemented in a variety of ways.

[0046] The steering rod 101 can, for example, be in the form of a rack and pinion, which interacts with a corresponding gear element 202 of the gear unit 201, for example in the form of a pinion.

[0047] Rotatable and linearly movable steering rods 101 are also conceivable, which, for example, have an external thread and interact with a corresponding gear element 202 of the gear unit 201, for example in the form of a worm and / or a threaded rod or similar.

[0048] When steering between the extreme left and extreme right positions, the steering rod 101 performs a linear movement with a full stroke. The transmission element 21 is designed such that one (in particular, complete) rotation of the transmission element 21 (in particular, over 360°) corresponds to the full stroke of the steering rod 101.

[0049] Thus, an absolute measuring sensor unit 20 can be provided. Advantageously, the sensor device 100 is attached to the gearbox unit 201.

[0050] As it is Fig. 2 As indicated, the transmission element 202 can be provided with teeth, e.g., at its end, into which the transmission element 21, which can be in the form of a gear, engages. The transmission ratio can be selected such that the transmission element 21 rotates a maximum of only once over the entire stroke of the steering rod 101.

[0051] To move the steering rod 101 through a full stroke, the gear element can rotate several times, e.g., 3 times. In this case, the ratio between the transmission element and the gear element 1 can be adjusted to 3. This allows the absolute position of the steering rod 101 to be unambiguously determined over a full stroke based on the detected angle of the transmission element.

[0052] A signal transmitter 22, which can be in the form of a magnet, for example, is connected to the transmission element 21. The signal transmitter 22 serves to determine the angle of the transmission element 21. This angle of the transmission element 21 ultimately indicates the position of the steering rod 101 (maximum one revolution over a full stroke).

[0053] As it is Fig. 2Furthermore, as indicated, the sensor device 100 can advantageously be constructed in such a way that the transmission element 21, the signal transmitter 22 and in particular a circuit board 24 including a signal detector 23 are accommodated in the housing 10.

[0054] The housing 10 can, for example, be in the form of a cover, e.g. made of plastic, preferably with an injection-molded connector 11. The injection-molded connector 11 enables simple wiring of the sensor device 100.

[0055] The assembly effort of the sensor device 100 is low, since only a modularly designed, individually handleable and interconnected component unit is mounted on the gearbox unit 201, preferably in only one assembly step.

[0056] As can be seen from the Figs. 2 and 3 As can be seen, the sensor device 100 can be designed in such a way that the tolerance chains between the signal transmitter 22 and the signal detector 23 are kept low.

[0057] The freedom from play between the transmission element 21 and the gear element 202 can advantageously be achieved directly during the assembly of the sensor device 100.

[0058] As it is Fig. 2 As indicated, it may be provided that the transmission element 21 is adjustable without play on the transmission element 202 of the transmission unit 201 when the sensor device 100 is mounted on the transmission unit 201.

[0059] For this purpose, the sensor device 100 as a whole can be placed on the gearbox unit 201 in a first direction R1 from top to bottom and then pressed onto the gearbox element 202 in a second direction R2 to enable backlash-free engagement of the transmission element 21 on the gearbox element 202 of the gearbox unit 201.

[0060] The transmission element 21 can be fixed to a bearing bolt L2 in a rotationally fixed manner, e.g., by hot riveting. The bearing bolt L2 can be rotatably mounted in the housing 10 by means of a bearing L1. Bearing bores L3 can be provided on the transmission element 21 to simplify its mounting and / or storage.

[0061] The sensor device 100 can preferably be switched on only when starting the vehicle F, e.g., when the vehicle F starts moving, in order to detect the position of the steering column. Subsequently, particularly during normal operation of the vehicle F, the sensor device 100 can be switched off again and the system can revert to an existing steering column position control. The existing steering column position control can, for example, rely on motor position sensing in the drive unit 203 or in the PowerPack.

[0062] Different measuring methods can be used to implement the angle measurement of the transmission element 21, e.g. magnetic, inductive, optical, etc.

[0063] A corresponding wheel actuator 200 for a steer-by-wire system S of a vehicle F also represents an aspect of the invention, wherein the wheel actuator 200 is configured to actuate a steering rod 101 of the vehicle F according to a steering request of the steer-by-wire system S, the wheel actuator 200 comprising: a sensor device 100 for determining a position of the steering rod 101, which can be designed as described above, and a gear unit 201 with a gear element 202 for providing a mechanical operative connection to the steering rod 101 of the vehicle F, wherein the transmission element 202 is designed to provide a specific transmission ratio to the transmission element 21 such that at most one revolution of the transmission element 21 represents a full stroke of the steering rod 101 of the vehicle F.

[0064] A corresponding steer-by-wire system S for a vehicle F with a corresponding wheel actuator 200 also represents an aspect of the invention. A corresponding vehicle F, in particular a highly automated and / or autonomously driving vehicle F, which may not have or need not have a steering wheel, with a corresponding steer-by-wire system S also represents an aspect of the invention.

[0065] Furthermore, a method for determining the position of a steering rod 101 of a vehicle F using a sensor device 100, which can be configured as described above and can be carried out, in particular, when a vehicle F is started, also constitutes an aspect of the invention. The method comprises: Determining the angle W of the transmission element 21, determining the absolute position P of the steering rod 101 using the angle W of the transmission element 21.

[0066] As mentioned above, the procedure can be carried out particularly when the vehicle F is started. Advantageously, the position P of the steering rod 101 can be determined independently of an engine position sensor in a drive unit 203 of the wheel actuator 200. Advantageously, the procedure can be terminated and / or the sensor unit 20 switched off after the absolute position P of the steering rod 101 has been determined, so that, particularly during normal operation of the vehicle F, an engine position sensor in a drive unit 203 of the wheel actuator 200 can take over the position determination of the steering rod 101.

[0067] The preceding explanation of the embodiments describes the present invention solely by way of examples. Naturally, individual features of the embodiments can be freely combined with one another, provided this is technically feasible, without departing from the scope of the present invention. Reference symbol list

[0068] 100 sensor device 10 Housing 11 Connector 12 Positioning pins 20 sensor units 21 Transmission element 22 Signal transmitter 23 Signal detector 24 Circuit board 101 Steering rod 200 wheel actuator 201Gear unit 202Gear element 203Drive unit MMotor 204Motor shaft 205worm wheel System Vehicle Angle Position L1 Bearing L2 Bearing bolt L3 Bearing bore R1 direction R2 direction

Claims

1. Sensor device (100) for a steering rod (101) of a vehicle (F), the steering rod (101) being drivable by a wheel actuator (200) of a steer-by-wire system (S) of a vehicle (F), and the wheel actuator (200) being designed to control the steering rod (101) of the vehicle (F) according to a steering request of the steer-by-wire system (S), the sensor unit (100) comprising: - a housing (10) for arranging the sensor device (100) on a gear unit (201) for driving the component, in particular a gear unit (201) of the wheel actuator (200), - a sensor unit (20) for determining a position of the component, in particular the steering rod (101) of the vehicle (F), the sensor unit (20) comprising the following elements: - a transmission element (21) for providing a mechanical operative connection to a gear element (202) of the gear unit (201), - a signal transmitter (22), which is connected to the transmission element (21) for conjoint rotation, for indicating an angle of the transmission element (21), characterized in that the transmission element (21) is designed such that at most one revolution of the transmission element (21) represents a full stroke of the component, in particular the steering rod (101) of the vehicle (F).

2. Sensor device (100) according to claim 1, wherein the housing (10) is designed to accommodate the sensor unit (20) with all the elements, and / or wherein the housing (10) is designed to be arranged in the form of a cover on the gear unit (201) of the wheel actuator (200) and thus to cover and preferably seal the sensor unit (20), and / or wherein the housing (10) is designed such that the sensor device (100) can be attached to the gear unit (201) of the wheel actuator (200) in the form of a modular, individually handleable and interconnected module, and / or wherein the housing (10) is designed such that the sensor device (100) can be attached to the gear unit (201) of the wheel actuator (200) in one assembly step.

3. Sensor device (100) according to either of the preceding claims, wherein the housing (10) comprises a plastics material, and / or wherein the housing (10) is designed in the form of an injection-molded component, and / or wherein the housing (10) comprises an, in particular molded-on, connector (11) and / or a cable tail in order to provide an electrical and / or data supply for the sensor unit (20).

4. Sensor device (100) according to claim 1 or 2, wherein the sensor unit (20) comprises a signal detector (23), and / or wherein the sensor unit (20) comprises a circuit board (24), and / or wherein a signal detector (23) is arranged on a circuit board (24) of the sensor unit (20), and / or wherein a circuit board (24) of the sensor unit (20) is attached to the housing (10), in particular using positioning pins (12), and / or wherein the sensor unit (20) incorporates at least one of the following measurement principles: - electromechanical, - magnetic, - inductive, - optical, etc.

5. Sensor device (100) according to any of the preceding claims, wherein the transmission element (21) is designed in the form of a gear, and / or wherein the transmission element (21) has a specific gear ratio to the gear element (202) of the gear unit (201), and / or wherein the transmission element (21) is adjustable without play on the gear element (202) of the gear unit (201) when the sensor device (100) is assembled on the gear unit (201).

6. Wheel actuator (200) for a steer-by-wire system (S) of a vehicle (F), wherein the wheel actuator (200) is designed to control a steering rod (101) of the vehicle (F) according to a steering request of the steer-by-wire system (S), the wheel actuator (200) comprising: a sensor device (100) according to any of the preceding claims for determining a position of the steering rod (101), and a gear unit (201) having a gear element (202) for providing a mechanical operative connection to the steering rod (101) of the vehicle (F), wherein the gear element (202) is designed to provide a specific gear ratio to the transmission element (21), so that at most one revolution of the transmission element (21) represents a full stroke of the steering rod (101) of the vehicle (F).

7. Wheel actuator (200) according to the preceding claim, wherein the gear element (202) is designed with teeth in order to provide the specific gear ratio to the transmission element (21).

8. Steer-by-wire system (S) for a vehicle (F), comprising a wheel actuator (200) according to any of the preceding claims.

9. Vehicle (F), in particular a highly automated and / or autonomously driving vehicle, comprising a steer-by-wire system (S) according to the preceding claim.

10. Method for determining a position of a steering rod (101) of a vehicle (F) using a sensor device (100) according to any of the preceding claims, in particular when starting a vehicle (F), comprising: - detecting the angle (W) of the transmission element (21), - determining the absolute position (P) of the steering rod (101) using the angle (W) of the transmission element (21).

11. Method according to the preceding claim, wherein the method is carried out when the vehicle (F) is started, and / or wherein the position (P) of the steering rod (101) is ascertained independently of an engine position detection device in a drive unit (203) of the wheel actuator (200), and / or wherein the method is terminated and / or the sensor unit (20) is switched off after the absolute position (P) of the steering rod (101) has been determined, so that, in particular during normal operation of the vehicle (F), an engine position detection device in a drive unit (203) of the wheel actuator (200) takes over the position determination of the steering rod (101).