Steer-by-wire setup, steer-by-wire method and an absolute position sensor for it

Abstract

A steer-by-wire setup and method, and an absolute position sensor for a vehicle, comprise a first motor with a stator and a rotor, a lead screw drive configured to mesh with a threaded section of a steering spindle and to move the steering spindle longitudinally as the lead screw drive rotates, and a rotor carrier sleeve coupled between the first rotor and the lead screw drive, configured to rotate about the longitudinal axis of the steering spindle. The setup also includes a first rotational position target marker arranged around the rotor carrier sleeve, the position of which uniquely corresponds to a position of the steering spindle, and a first rotational position sensor configured to detect movement of the first rotational position target marker and to send a sensor signal to a control unit.

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] In recent years, there has been growing interest in the development of autonomous vehicles capable of driving and operating without human intervention. One of the key components of an autonomous vehicle is the steering system, which is responsible for controlling the vehicle's direction of travel. Conventional steering systems typically include a steering wheel, a steering column, and a mechanical linkage connecting the steering wheel to the vehicle's wheels. In autonomous vehicles, the steering wheel can be eliminated, and the steering system can be controlled electronically by a vehicle control unit via a steer-by-wire setup.

[0003] Steer-by-wire systems are known in the art and generally comprise a motor that rotates a threaded drive, which in turn moves a steering spindle along its longitudinal axis. The steering spindle is connected to the vehicle's wheels via tie rods, and its position determines the vehicle's direction. Knowing the absolute position of the steering spindle is essential for precise steering.

[0004] Various methods and devices have been proposed for measuring the position of a steering column in a vehicle. US Patent No. 5930905 discloses a method and a device for measuring the angle of a vehicle's steering column. The steering column interacts with two gears, the angular positions of which are detected by two sensors. The angular position of the steering column is determined from the angular positions detected by the two sensors.

[0005] However, the known devices and methods have some shortcomings. One of the main problems is that they are designed to measure the angle of the steering column, which is not applicable to autonomous vehicles that do not have a steering column. Furthermore, the known devices are typically located adjacent to the steering column, which can be easily accommodated within the vehicle cabin. In contrast, the space constraints in an autonomous vehicle without a steering wheel make it difficult to integrate the known devices into a compact arrangement. overview

[0006] In a first aspect, the invention provides a steer-by-wire assembly comprising a first motor with a first stator and a first rotor, a lead screw drive configured to engage with a threaded section of a steering spindle and to move the steering spindle longitudinally when the lead screw drive rotates, and a rotor carrier sleeve coupled between the first rotor and the lead screw drive, configured to rotate about the longitudinal axis of the steering spindle. The assembly also includes a first rotational position target marker arranged around the rotor carrier sleeve, the position of which corresponds to a unique position of the steering spindle, and a first rotational position sensor configured to detect the movement of the first rotational position target marker and to send a sensor signal to a control unit.

[0007] In an optional embodiment, the assembly further comprises a first sensor gear transmission designed to engage in rotation with the rotor carrier sleeve and the first rotational position target marker, and which provides a reduction such that the first rotational position target marker rotates more slowly than the rotor carrier sleeve.

[0008] The first rotation position target marker may be designed to rotate by less than 360° when the steering spindle moves from a first fully turned wheel position to a second fully turned wheel position.

[0009] In another optional embodiment, the assembly includes a second rotational position target marker arranged around the rotor carrier sleeve, wherein the position of the second rotational position target marker together with the position of the first rotational position target marker corresponds to a unique position of the steering spindle.

[0010] The setup can also include a second rotary position sensor designed to detect the movement of the second rotary position target marker and send a sensor signal to the control unit.

[0011] In yet another optional embodiment, the assembly features a second sensor gear transmission designed to engage in rotation with the rotor carrier sleeve and the second rotational position target marker, and which provides a reduction such that the second rotational position target marker rotates more slowly than the rotor carrier sleeve.

[0012] The gear ratio of the second sensor gear ratio can differ from the gear ratio of the first sensor gear ratio.

[0013] Optionally, the first sensor gear ratio includes a first prime number of teeth, and the second sensor gear ratio includes a second prime number of teeth that differs from the first prime number of teeth. The product of the first prime number of teeth and the second prime number of teeth is greater than the total number of revolutions the lead screw drive requires to move the steering spindle from a first fully turned wheel position to a second fully turned wheel position via a complete stroke.

[0014] In some embodiments, the assembly may further include a second motor with a second stator and a second rotor, wherein the second motor is designed to additionally rotate the threaded drive in order to move the steering spindle along the longitudinal axis.

[0015] Optionally, the thread drive is selected from the group consisting of a ball screw drive (ball recirculation thread) and a roller screw drive.

[0016] Optionally, the first rotary position sensor and / or the second rotary position sensor is selected from the group consisting of an optical encoder, a magnetic encoder, an inductive encoder, a capacitive encoder, a Hall effect sensor, a resolver, a potentiometer encoder and a cam follower.

[0017] Optionally, the first rotational position target marker and / or the second rotational position target marker are selected from the group consisting of a magnetic encoder, a patterned disc, a coded disc, a grid disc, a retroreflector disc, a slotted disc, and a vernier scale disc.

[0018] Optionally, the first sensor gear ratio and / or the second sensor gear ratio is selected from the group consisting of planetary gears, harmonic gears, spur gears, bevel gears and worm gears.

[0019] Optionally, the control unit is configured to determine the absolute position of the steering spindle based on the received sensor signals from the first rotary position sensor and / or the second rotary position sensor, using a reference table stored in a memory.

[0020] Optionally, the control unit is further configured to determine the absolute position of the steering spindle based on a detected unique rotational position from both the first rotational position target marker and the second rotational position target marker using the vernier principle, when signals are received from both the first rotational position sensor and the second rotational position sensor.

[0021] The control unit is optionally further configured to determine the absolute position of the steering spindle based on the detected unique angular position of the first rotary position target marker when only the signal from the first rotary position sensor is used.

[0022] Optionally, the first rotational position target marking and / or the second rotational position target marking are arranged around the circumference of the rotor carrier sleeve.

[0023] In a second aspect of the invention, a method for determining the absolute position of a steering spindle in a steer-by-wire setup is proposed, comprising a first motor with a first stator and a first rotor, a threaded drive configured to engage with a threaded portion of a steering spindle and, when the threaded drive rotates, to move the steering spindle longitudinally, and a rotor carrier sleeve coupled between the first rotor and the threaded drive, configured to rotate about the longitudinal axis of the steering spindle;The method involves detecting the position of the first rotational position target marker with the first rotational position sensor, wherein the position of the first rotational position target marker uniquely corresponds to a position of the steering spindle, receiving the detected sensor signal from the first rotational position sensor at the control unit, and determining the absolute position of the steering spindle based on the received sensor signal from the rotational position sensor.

[0024] In an optional example, the procedure involves detecting the position of the second rotary position target mark with the second rotary position sensor, receiving the detected sensor signal from the second rotary position sensor at the control unit, and determining the absolute steering spindle position based on the detected unique positions of both the first rotary position target mark and the second rotary position target mark using the vernier principle.

[0025] Finally, according to another aspect of the invention, an absolute position sensor is provided for a steer-by-wire setup comprising a first motor with a first stator and a first rotor, a lead screw drive configured to engage with a threaded portion of a steering spindle and to move the steering spindle longitudinally when the lead screw drive rotates, and a rotor carrier sleeve coupled between the first rotor and the lead screw drive and configured to rotate about the longitudinal axis of the steering spindle, wherein the absolute position sensor comprises a first rotational position target marker arranged around a rotor carrier sleeve connected to a rotor of a motor, the position of the first rotational position target marker uniquely corresponding to a position of the steering spindle, and a first rotational position sensor configured toto detect the movement of the first rotational position target marker and send a sensor signal to a control unit. Brief description of the drawings

[0026] The invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 a perspective view of a steer-by-wire setup according to an exemplary embodiment, Fig. 2 a cross-sectional view of the steer-by-wire setup according to an exemplary embodiment, Fig. 3 a perspective exploded view of an absolute position sensor setup according to an exemplary embodiment, Fig. 4 a lateral cross-sectional view of the absolute position sensor assembly according to the exemplary embodiment is, Fig. 5 a front view in cross-section of an absolute position sensor assembly according to an exemplary embodiment, Fig. 6 is a perspective partial view of an absolute position sensor setup according to another embodiment, Fig. 7 a front view in cross-section of an absolute position sensor assembly according to another embodiment, Fig. 8 is a schematic block diagram of a steer-by-wire setup according to an exemplary embodiment, Fig. 9 a flowchart of a method for applying the steer-by-wire setup according to an exemplary embodiment is and Fig. Figure 10 shows a cross-sectional view of an absolute position sensor assembly according to another embodiment. Detailed description

[0027] According to a Fig. The embodiment shown in Figure 1 comprises a steer-by-wire assembly 100, a housing 101, a first tie rod 102, a second tie rod 103, a steering spindle 114, a motor assembly 142 and an absolute position sensor assembly 125. Fig. Figure 1 shows a perspective view of the steer-by-wire assembly 100. The housing 101 can be mounted on a vehicle frame and carries various components of the steer-by-wire assembly 100.

[0028] In one embodiment, the steer-by-wire assembly 100 is designed to provide precise and reliable control of the steering system in a vehicle. The steer-by-wire assembly 100 comprises various components that work together to convert the rotary motion of a motor into a linear motion of a steering spindle 114, which in turn controls the steering angle of the vehicle's wheels. The steer-by-wire assembly 100 offers several advantages over conventional mechanical steering systems, such as reduced complexity, improved responsiveness, and enhanced safety features.

[0029] In some embodiments, the steer-by-wire assembly 100 includes a housing 101 that supports and protects various components of the steer-by-wire assembly 100. The housing 101 can be mounted to a vehicle frame and provides a stable and secure platform for the steer-by-wire assembly 100. The housing 101 can be made of a durable material, such as metal or high-strength plastic, to withstand the stresses and vibrations to which it is subjected during vehicle operation.

[0030] The steer-by-wire assembly 100 also includes a first tie rod 102 and a second tie rod 103, which are connected to the steering spindle 114 via first and second tie rod couplings 115 and 116, respectively. The first and second tie rod couplings 115 and 116 can, for example, be ball joints. The first and second tie rods 102 and 103 transmit the linear motion of the steering spindle 114 to the vehicle wheels, enabling precise control of the steering angle. The first and second tie rods 102 and 103 can be made of a strong and lightweight material, such as steel or aluminum, to ensure reliable performance and minimize the overall weight of the assembly.

[0031] The first tie rod 102 is connected to the first tie rod coupling 115 at a first steering spindle end 112 of the steering spindle 114. Similarly, the second tie rod 103 is connected to a second tie rod coupling 116 at a second steering spindle end 113 of the steering spindle 114. The steering spindle 114 extends along a longitudinal axis 104 and includes a threaded section 120 that meshes with the threaded drive 117.

[0032] In some embodiments, the housing 101 of the steer-by-wire assembly 100 is designed for easy mounting to a vehicle frame (not shown). This allows for simple integration of the steer-by-wire assembly 100 into the vehicle's steering system, reducing complexity and installation time. The housing 101 may have mounting points or brackets (a bracket) that facilitate secure attachment to the vehicle frame and ensure proper alignment and stability during operation.

[0033] With reference to Fig. Section 2 will now discuss the steer-by-wire setup in more detail. Fig. Figure 2 shows a cross-sectional view of the steer-by-wire setup 100.

[0034] In one example, the steer-by-wire assembly 100 includes a steering spindle 114 extending along a longitudinal axis 104. The steering spindle 114 is designed to move longitudinally in response to the rotation of the lead screw 117, which engages with the threaded section 120 of the steering spindle 114. The lead screw 117 can be a ball screw or a roller screw, both of which provide high efficiency and precision in converting the rotary motion of a motor into linear motion of the steering spindle 114. In other embodiments, any suitable lead screw 117 can be used to convert the rotary motion from the motor assembly 142 into linear motion of the steering spindle 114.

[0035] In some embodiments, the threaded drive 117 engages with the threaded section 120 of the steering spindle 114 to effect the linear movement of the steering spindle 114 along the longitudinal axis 104. The engagement between the threaded drive 117 and the threaded section 120 establishes a secure and reliable connection and allows precise control of the position of the steering spindle 114 and thus of the steering angle of the vehicle wheels.

[0036] In one embodiment, the rotation of the threaded drive 117 causes the steering spindle 114 to move linearly along the longitudinal axis 104. This linear movement of the steering spindle 114 is transmitted to the vehicle wheels via the first and second tie rods 102, 103, enabling precise control of the steering angle. The range of motion of the steering spindle 114 can be defined by a predetermined number of revolutions of the rotor carrier sleeve 111, which in turn corresponds to a range of motion from a first fully turned position to a second fully turned position.

[0037] The engine design 142 will now be discussed in more detail with reference to the Fig. 1 and Fig. 2 discussed.

[0038] The motor assembly 142 drives the rotation of the threaded drive 117 to move the steering spindle 114 along the longitudinal axis 104. The motor assembly 142 comprises a first motor 105 with a first stator 106 and a first rotor 107. The first stator 106 is stationary with respect to the housing 101, while the first rotor 107 is coupled to the rotor carrier sleeve 111.

[0039] In some embodiments, the steer-by-wire assembly 100 comprises a motor assembly 142 that drives the rotation of the lead screw 117 and causes the linear movement of the steering spindle along the longitudinal axis 104. The motor assembly 142 can include a first motor 105 with a first stator 106 and a first rotor 107, as well as optionally a second motor 108 with a second stator 109 and a second rotor 110. The first and second motors 105 and 108 can be configured to provide additional rotational drive or an alternative drive source for the rotation of the lead screw 117, thus ensuring smooth and precise control of the lead screw's position.

[0040] The second stator 109 is stationary with respect to the housing 101, while the rotor 110 is coupled to the rotor support sleeve 111. The second motor 108 provides additional rotary drive for the screw drive 117 to move the steering spindle 114 along the longitudinal axis 104.

[0041] The motor assembly 142 is coupled to the rotor support sleeve 111, which connects the motor rotor to the threaded drive 117. The rotor support sleeve 111 is designed to rotate about the longitudinal axis 104 of the steering spindle 114, thereby transmitting the rotation from the first and / or second motor 105, 108 to the threaded drive 117. The rotor support sleeve 111 can be rotatably mounted in the housing 101 by means of a first support sleeve bearing 118 and a second support sleeve bearing 119, which ensures smooth and reliable operation.

[0042] While the embodiments shown in the accompanying figures depict the steer-by-wire setup 100 with a first motor 105 and a second motor 108, some embodiments provide only a single first motor 105. A preferred embodiment is a steer-by-wire setup 100 with a first and a second motor 105, 108, thus providing additional redundancy in the event of a failure of one of the first and second motors 105, 108. Nevertheless, some embodiments may include any number of motors, e.g., one, two, three, etc.

[0043] The rotor support sleeve 111 is connected between the motor rotor and the threaded drive 117 and is designed to rotate about the longitudinal axis 104 of the longitudinal spindle 114. The rotor support sleeve 111 is rotatably mounted in the housing 101 by a first support sleeve bearing 118 and a second support sleeve bearing 119.

[0044] The screw drive 117 is rotatably mounted around the threaded spindle 114 and engages with the threaded section 120 of the threaded spindle 114, thus converting the motor rotation into linear motion of the threaded spindle 114. The screw drive 117 can be a ball screw drive or a roller screw drive.

[0045] The steer-by-wire assembly 100 can also include an absolute position sensor assembly 125, which precisely determines the position of the threaded spindle 114, thus ensuring precise control of the vehicle's steering angle. The absolute position sensor assembly 125 will now be described in more detail with reference to the Fig. 3 and Fig. 4 discussed. Fig. Figure 3 shows a perspective exploded view of the absolute position sensor assembly 125. Fig. Figure 4 shows a cross-sectional view of the absolute position sensor assembly 125.

[0046] In one embodiment, the absolute position sensor assembly 125 is a component of the steer-by-wire assembly 100. The absolute position sensor assembly 125 is designed to precisely determine the position of the steering spindle 114. The absolute position sensor assembly 125 comprises a first rotational position target marker 127 and a first rotational position sensor 126. The first rotational position target marker 127 is connected to the rotor carrier sleeve 111, so that the first rotational position target marker 127 moves with the rotor carrier sleeve 111. In this way, the rotational movement of the first rotor 107 or the second rotor 110 is transmitted to the first rotational position target marker 127. The first rotary position sensor 126 is configured to detect the relative movement of the first rotary position target marker 127 with respect to the first rotary position sensor 126 and to send a sensor signal to a control unit 121.The first rotational position target marker 127 is optionally arranged around the circumference of the rotor carrier sleeve 111, and its position corresponds to a unique position of the steering spindle 114. This unique positional correspondence ensures that the position of the steering spindle 114, and therefore the angle of the wheels, is known at all times. This also includes situations where the power supply to the steer-by-wire assembly 100 or the vehicle fails, or the steering wheel is moved (for example, during routine servicing) when the steer-by-wire assembly 100 is not receiving electrical power. The examples described here therefore avoid scenarios that could lead to doubts regarding the actual position of the wheels.

[0047] The first rotary position sensor 126 is configured to detect movement of the first rotary position target marker 127 and send a sensor signal to a control unit 121. The control unit 121 processes the sensor signals to determine the absolute position of the steering spindle 114. Accurate determination of the steering spindle 114 enables precise control of the vehicle's steering, thus improving the vehicle's safety and performance.

[0048] As in Fig. 7 or Fig. As shown in Figure 10, the absolute position sensor assembly 125 can, in some embodiments, further include a second rotary position target marker 130 and a second rotary position sensor 129. The sensor signal generated by the second rotary position sensor 129 can be used separately from or together with the sensor signal generated by the first rotary position sensor 126. If the sensor signal generated by the second rotary position sensor 129 is independent, then the second rotary position sensor 129 is identical to the first rotary position sensor 126 and is provided for redundancy in case the first rotary position sensor 126 fails. In the example where the signals from the first rotary position sensor 126 and the second rotary position sensor 129 are used together, the design of the absolute position sensor assembly 125 can be simpler and more compact.The second rotational position target marker 130 is also optionally arranged around the circumference of the rotor carrier sleeve 111. The position of the second rotational position target marker 130, together with the position of the first rotational position target marker 127, corresponds to a unique position of the steering spindle 114. This combined unique position determination creates an additional level of accuracy and redundancy, further improving the precision and reliability of the steer-by-wire assembly 100.

[0049] Similar to the first rotary position sensor 126, the second rotary position sensor 129 is configured to detect movement of the second rotary position target marker 130 and send a sensor signal to the control unit 121. The control unit 121 processes the sensor signals from both the first rotary position sensor 126 and the second rotary position sensor 129 to determine the absolute position of the steering spindle 114 with even greater accuracy.

[0050] Thus, in some embodiments, the absolute position of the steering spindle 114 is determined using a single first rotary position sensor 126. In other embodiments, the absolute position of the steering spindle 114 is determined using multiple sensors, for example, with the first rotary position sensor 126 and with the second rotary position sensor 129. These different examples of the absolute position sensor setup 125 are discussed in more detail below.

[0051] In some embodiments, the absolute position sensor assembly 125 can include a first sensor gear transmission 128. The first sensor gear transmission 128 is designed to engage with the rotor carrier sleeve 111 and the first rotational position target marker 127 and to effect a reduction, such that the first rotational position target marker 127 rotates more slowly than the rotor carrier sleeve 111. This reduction mechanism enables a more precise determination of the position of the threaded spindle 114, which is made possible because the first rotational position target marker 127 rotates over a smaller angular range, thereby increasing the resolution of the position measurement.

[0052] In some embodiments, the reduction of the first sensor gear ratio 128 is such that the first rotation position target marker 127 rotates by less than 360° when the rotor carrier sleeve 111 rotates over the entire rotation range of the movement of the rotor carrier sleeve 111 required to move the steering spindle 114 from a first fully turned position to a second fully turned position. In some embodiments, the first rotational position target marker 127 is configured to rotate over an angular range of 0° to 350°, 0° to 340°, 0° to 330°, 0° to 320°, 0° to 310°, 0° to 300°, 0° to 290°, 0° to 280°, 0° to 270°, 0° to 270°, 0° to 260°, 0° to 250°, 0° to 240°, 0° to 230°, etc. The first rotational position target marker 127 is configured to rotate over any angular range of less than 360°.This means that the angular position of the first rotation position target mark 127 is unique for each position of the threaded spindle 114 from the first fully engaged position to the second fully engaged position.

[0053] In some embodiments, the absolute position sensor assembly 125 can optionally include a second sensor gear transmission 131. The second sensor gear transmission 131 is designed to engage rotationally with the rotor carrier sleeve 111 and the second rotational position target marker 130 and to effect a reduction, so that the second rotational position target marker 130 rotates more slowly than the rotor carrier sleeve 111.

[0054] The second sensor gear transmission 131, if present, is designed to engage rotationally with the rotor carrier sleeve 111 and the second rotational position target marker 130, thus reducing the speed of the second rotational position target marker 130. However, the sensor signals received from both the first rotational position sensor 126 and the second rotational position sensor 129 are used to determine the absolute position of the steering spindle 114. In this case, the combination of sensor signals from both the first rotational position sensor 126 and the second rotational position sensor 129 corresponds to a unique position of the steering spindle 114 between the first fully turned position and the second fully turned position. This is discussed in more detail below.In some embodiments, the gear ratio of the second sensor gear ratio 131 differs from the gear ratio of the first gear ratio 128, which further increases the accuracy and redundancy of the determination of the absolute position.

[0055] In some embodiments, the first sensor gear transmission 128 and the second sensor gear transmission 131 can have different gear ratios, such as a planetary gear arrangement 132, a harmonic gear transmission 500, spur gear transmission, bevel gear transmission, worm gear transmission, and rack and pinion gear transmission. Any other suitable gear mechanism can be used to couple the rotor carrier sleeve 111 to the first rotational position target marker 127 or to the second rotational position target marker 130.

[0056] In the Fig. In the example shown in Figure 3, the first sensor gear transmission 128 has a first planetary gear assembly 132 with a first sun gear 133, which is fixed with respect to the rotor carrier sleeve 111. The first sun gear 133 is designed to mesh with a first plurality of planet gears 134, which are mounted on a first carrier 136. The first planet gears mesh with a first ring gear 135. Fig. Figure 3 shows an optional sequence of first planetary gear assemblies 132 coupled together. By providing a plurality of first planetary gear assemblies 132, the gear ratio can be reduced in a small volume. This means that the radial size of the absolute position sensor assembly 125 can be kept small. Fig. Figure 4 shows how the absolute position sensor assembly 125 results in a compact structure when assembled.

[0057] In the Fig. In the embodiment shown in Figure 10, the absolute position sensor assembly 125 optionally comprises a planetary gear assembly 132 with a first sun gear 133, a single set of first planet gears 134, and a single first ring gear 135. In some embodiments, the Fig. 3 planetary gear assembly 132 shown by a planetary gear assembly 132 as in Fig. 10 shown replaced to provide an absolute position sensor setup 125. In the in Fig. In the arrangement shown in Figure 10, the second rotational position target marker 130 is also coupled to the rotor carrier sleeve 111 via a planetary gear assembly 132. The second sensor gear transmission 131 comprises a second planetary gear assembly 141 with a second sun gear, which is fixed relative to the rotor carrier sleeve 111. The second sun gear 137 meshes with a second set of planet gears 138, which are mounted on a second carrier 140. The second planet gears 138 mesh with a second ring gear 139. Fig. Figure 3 shows an optional sequence of interconnected first planetary gear sets 132.

[0058] The largest diameter of the absolute position sensor assembly 125 is smaller than the largest diameter of the housing 101. This means that the absolute position sensor assembly 125 is compact and does not increase the overall size of the steer-by-wire assembly 100.

[0059] As with reference to Fig. As discussed in section 3, the first sensor gear transmission 128 comprises a planetary gear assembly 132. However, in other embodiments, other mechanisms can be used to couple the rotor carrier sleeve 111 with the rotation position target marker 127.

[0060] Such an alternative structure is in Fig. 5 shown. Fig. Figure 5 shows a front cross-sectional view of the absolute position sensor assembly 125, wherein the first sensor gear transmission 128 comprises a harmonic transmission (voltage shaft transmission) 500. The harmonic transmission 500 includes a shaft generator 502, which is coupled to the rotor carrier sleeve 111. The shaft generator 502 meshes with the flexible gear part 504, which engages with the annular gear part 506. The annular gear part 506 is connected to the first rotational position target marker 127 and causes the first rotational position target marker 127 to rotate relative to the first rotational position sensor 126 when the rotor carrier sleeve 111 rotates. Similar to the one in Fig. In the planetary gear assembly 132 shown, the harmonic gear 500 provides a reduction, so that the rotation target marker 127 rotates by less than 360°. Furthermore, the Fig. The planetary gear assembly 132 shown in Figure 10 can be replaced by a harmonic gear assembly 500 for both the first and second gear ratios 128, 131.

[0061] As discussed above, in one embodiment, the control unit 121 determines the absolute position of the steering spindle 114 based on the detected unique angular position of the first rotary position target marker 127 when only the signal from the first rotary position sensor 126 is used. In some embodiments, the second rotary position sensor 129 is of the same design as the first rotary position sensor 126 and functions in the same way. In this way, the second rotary position sensor 129 can be used for additional sensor redundancy. In this example, the second rotary position sensor 129 is not used together with the first rotary position sensor 126 to apply the vernier scale principle.This configuration can be advantageous in situations where the second rotary position sensor 129 is not present or is not functioning correctly, as it is still possible to determine the exact position of the steering spindle 114 using only the first rotary position sensor 126.

[0062] Another alternative for the gear ratio design is in Fig. 6 and Fig. 7 shown. Fig. Figure 6 shows a perspective view of the absolute position sensor assembly 125, where the first sensor gear transmission 128 has a worm gear assembly 600. In this case, a worm gear 602 is fixed with respect to the rotor carrier sleeve 111 and rotates circumferentially around it (in Fig. (6 partially shown). The worm gear 602 meshes with a first worm gear 604. The first rotation position target marker 127 is attached to the first worm gear 604 and rotates relative to the first rotation position sensor 126 when the rotor carrier sleeve 111 rotates. In this case, the first rotation position target marker 127 is located near the rotor carrier sleeve 111, but is not arranged circumferentially around the rotor carrier sleeve 111.

[0063] Fig. Figure 7 shows a setup in which the first and second sensor gear ratios 128, 131 are connected by a worm gear assembly 600 as described above. Fig. The following configurations are described in Figure 6. In this case, the absolute position sensor assembly 125 includes a second worm gear 606, which also meshes with the worm gear 602. In this case, the second rotational position target marker 130 is attached to the second worm gear 606 and rotates relative to the second rotational position sensor 129 when the rotor carrier sleeve 111 rotates. Similar to the other examples, the gear ratio of the first worm gear 604 is different from that of the second worm gear 606. In this case, the first rotational position target marker 127 and the second rotational position target marker 130 are attached close to the rotor carrier sleeve 111 and arranged together around the circumference of the rotor carrier sleeve 111.

[0064] The first sensor gear ratio 128 can have a first prime number of teeth, while the second sensor gear ratio 131 can have a second prime number of teeth that differs from the first prime number of teeth. In some embodiments, the gear ratios of the first sensor gear ratio 128 and the second sensor gear ratio 131 can both be prime numbers. This configuration ensures that the first and second sensor gear ratios 128 and 131 have a unique engagement pattern in every position of the steering spindle 114. In some embodiments, the total number of revolutions of the rotor carrier sleeve 111 required to move the steering spindle 114 from the first fully turned position to the second fully turned position is less than the product of the gear ratios of the first sensor gear ratio 128 and the second sensor gear ratio 131.For example, 32 revolutions of the rotor carrier sleeve 111 may be required to move the steering spindle 114 from the first fully turned position to the second fully turned position. The gear ratios of the first sensor gear ratio 128 and the second sensor gear ratio 131 can be 7:1 and 5:1, respectively. In other examples, the gear ratios of the first sensor gear ratio 128 and the second sensor gear ratio 131 can be selected from 2:1, 3:1, 5:1, 7:1, 11:1, 13:1, 17:1, 19:1, 23:1, 29:1, 31:1, 37:1, 41:1, 43:1, 47:1, 53:1, etc. The use of the first prime number of teeth and the second prime number of teeth advantageously ensures that the absolute position sensor setup 125 yields output values ​​(for example, the combination of the output from the first rotary position sensor 126 and the output from the second rotary position sensor 129) that are always unique.This means that for any combination of outputs from the first rotary position sensor 126 and the second rotary position sensor 129, there is no single point between the two fully turned positions where the combination of outputs would be the same. This enables the absolute position determination of the steering spindle 114 and the wheels.

[0065] As mentioned above, the sensor signals from the first and / or the second rotary position sensors 126, 129 are used to determine the absolute position of the steering spindle 114. In one embodiment, the steer-by-wire system 100 comprises components in the form of a control unit 121 and a memory 123, which are configured to process sensor signals and determine the absolute position of the steering spindle 114. The control unit 121 can include a first electronic control unit (ECU) 121, which sends control commands to the motor assembly 142 and receives commands from a vehicle control unit (VCU) 800. The control unit (ECU) 121 can include a microprocessor 122 and a memory 123 for storing data and executing commands. In another embodiment, a second ECU (Electronic Control Unit) 802 is additionally or alternatively configured to process sensor signals and determine the absolute position of the steering spindle 114.If both the first ECU 121 and the second ECU 802 are able to determine the absolute position of the steering spindle 114, this increases the redundancy of the overall system.

[0066] In some embodiments, the microprocessor 122 is responsible for executing instructions and processing data received from the first rotary position sensor 126 and / or the second rotary position sensor 129. The memory can be any suitable type of memory, such as volatile or non-volatile memory 123, and can store various data and instructions required for the operation of the control unit 121.

[0067] In one embodiment, a reference table 124 is stored in memory 123. This table contains relationship information between the absolute positions of the steering spindle 114 and the first rotary position target marker 127 and / or the second rotary position target marker 130. The reference table 124 can be pre-programmed or dynamically updated during operation of the steer-by-wire system 100. The reference table 124 allows the control unit 121 to determine the absolute position of the steering spindle 114 based on the sensor signals received from the first rotary position sensor 126 and / or the second rotary position sensor 129.

[0068] The control unit 121 is configured to determine the absolute position of the steering spindle 114 based on the sensor signals received from the first rotary position sensor 126 and / or the second rotary position sensor 129, using the reference table 124 stored in memory 123. This enables a precise and reliable determination of the position of the steering spindle 114, which is essential for the correct functioning of the steer-by-wire system 100.

[0069] As discussed in some examples, the control unit 121 is configured to determine the absolute position of the steering spindle 114 based on detected unique rotational positions from both the first rotational position target marker 127 and the second rotational position target marker 130, using the vernier principle, when signals are received from both the first rotational position sensor 126 and the second rotational position sensor 129. The vernier principle enables increased accuracy and resolution in determining the absolute position of the steering spindle 114 by combining the unique positions from both the first rotational position target marker 127 and the second rotational position target marker 130. This configuration can be advantageous in situations where higher precision and accuracy are required for the operation of the steer-by-wire setup 100.

[0070] The method for determining the absolute position of the steering spindle 114 in a steer-by-wire setup 100 is now described with reference to Fig. 9 discussed in more detail. This method enables the precise and reliable determination of the position of the steering spindle 114.

[0071] In an example illustrating the procedure for the first rotary position sensor 126 as in relation to the Fig. As described in sections 1 to 6, the method involves detecting the position of the first rotary position target marker 127 with the first rotary position sensor 126, as shown in step 900. In this case, the first rotary position sensor 126 is an absolute position sensor as described above. The first rotary position target marker 127 is arranged circumferentially around the rotor carrier sleeve 111, and its position corresponds to a unique position of the steering spindle 114. By detecting the position of the first rotary position target marker 127, the method can precisely determine the absolute position of the steering spindle 114. The first rotary position sensor 126 generates a sensor signal when it detects a relative movement of the first rotary position target marker 127 with respect to the first rotary position sensor 126. The control unit 121 receives the sensor signal from the first rotary position sensor 126, as shown in step 902.

[0072] The control unit 121 is configured to determine the absolute position of the steering spindle 114, as shown in step 904. In step 904, the control unit 121 determines the absolute position based on the sensor signal received from the first rotary position sensor 126 and using a reference table 124 stored in memory 123. The reference table 124 contains information about the dependence of the absolute position of the steering spindle 114 on the position of the first rotary position target marker 127. By using the reference table 124, the procedure can quickly and accurately determine the absolute position 114 based on the detected sensor signal, which is essential for the proper functioning of the steer-by-wire system. The reference table 124 can optionally contain a list of position parameters of the steering spindle 114, e.g.Displacements of the steering spindle 114 relative to a central position, each corresponding to an angular position of the first rotational position target mark 127. Alternatively, the reference table 124 can be replaced by a position calculation algorithm that calculates the position of the steering spindle 114 based on the angular position of the first rotational position target mark 127. In this case, the control unit 121 is configured to dynamically determine the position of the steering spindle 114.

[0073] The control unit 121 is configured to optionally send a signal containing the absolute position information of the steering spindle 114 once its absolute position has been determined, as shown in step 906. The signal can be sent from the control unit 121 to another component, such as the second control unit ECU 802, the vehicle control unit 800, or any other component in the steer-by-wire setup 100 or in the vehicle. In this example, the procedure applies only steps 900, 902, 904, and 906 for the first rotary position sensor 126, which is used as the absolute position sensor.

[0074] In some embodiments, the method may also include detecting the position of the second rotary position target marker 130 with the second rotary position sensor 129, as shown in step 908. In this case, the method is as described with reference to Fig. 7 and Fig. The procedures described in section 10 are as follows. That is, the combined outputs from the first rotary position sensor 126 and the second rotary position sensor 129 are used to determine the absolute position using the vernier scale principle. The second rotary position target mark 130 is also arranged circumferentially around the rotor carrier sleeve 111, and its position, together with the position of the first rotary position target mark 127, corresponds to a unique position of the steering spindle 114. The second rotary position sensor 129 generates a sensor signal upon detecting relative movement of the second rotary position target mark 130 relative to the second rotary position sensor 129. The control unit 121 receives the sensor signal from the second rotary position sensor 129, as shown in step 908.

[0075] When signals are received from both the first rotary position sensor 126 and the second rotary position sensor 129, as shown in steps 902 and 910, the control unit 121 is further configured to determine the absolute position of the steering spindle 114, as shown in step 904.

[0076] Step 904 is the same as previously discussed, except that the absolute position of the steering spindle 114 is determined based on the unique rotational position of both the first rotational position target mark 127 and the second rotational position target mark 130. The control unit 121 is configured to apply the vernier principle to determine the absolute position of the steering spindle 114 from the angular positions of the first and second rotational position target marks 127 and 130. The vernier principle allows for the precise determination of the absolute position of the steering spindle 114 by combining the detected unique positions of both the first and second rotational position target marks.This means that the absolute position of the steering spindle 114 is continuously determined throughout the entire movement of the threaded drive 117 of the steering system from the first fully turned position to the second fully turned position. In this case, the procedure, which uses the first rotary position sensor 126 and the second rotary position sensor 129, includes steps 900, 902, 904, 906, 908, and 910 as shown in [reference]. Fig. 9 shown.

[0077] After that, the control unit can proceed to step 906 as before.

[0078] The absolute position sensor assembly 150 in the steer-by-wire assembly 100 can include various types of first and / or second rotary position sensors 126, 129 and of first / or second rotary position target markers 127, 130, depending on the specific requirements of the application and the desired performance characteristics.

[0079] In some embodiments, the first rotary position sensor 126 and / or the second rotary position sensor 129 can be selected from the group consisting of an optical encoder, a magnetic encoder, an inductive encoder, a capacitive encoder, a Hall-effect sensor, a resolver, a potentiometer encoder, and a cam follower. These different sensor technologies offer various advantages in terms of accuracy, resolution, robustness, and cost, which allows the steer-by-wire setup 100 to be adapted to the requirements of the specific application.

[0080] In some examples, the first rotational position target marker 127 and / or the second rotational position target marker 130 can be selected from the group consisting of a magnetic encoder, a patterned disc, a coded disc, a grid disc, a retroreflector disc, a slotted disc, and a vernier scale disc. These various target markers offer a range of options for encoding the unique position of the steering spindle 114, enabling the absolute position sensor assembly 125 to achieve the desired level of precision and reliability in determining the position of the steering spindle 114.

[0081] In an embodiment, two or more embodiments can be combined. Features of one embodiment can be combined with features of other embodiments.

[0082] Exemplary embodiments of the present invention have been discussed, particularly with reference to the illustrated examples. However, it should be acknowledged that variations and modifications within the scope of the invention are possible in these exemplary embodiments. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 5930905

[0004]

Claims

[1] Steer-by-wire setup (100) which features: a first motor (105) with a first stator (106) and a first rotor (107), a threaded drive (117) designed to engage with a threaded section (120) of a steering spindle (114) and to move the steering spindle (114) in the longitudinal direction when the threaded drive (117) rotates, a rotor carrier sleeve (111) which is coupled between the first rotor (107) and the threaded drive (117) and is designed to rotate about the longitudinal axis (104) of the steering spindle (114), a first rotation position target marker (127) arranged around the rotor carrier sleeve (111), wherein the position of the first rotation position target marker (127) uniquely corresponds to a position of the steering spindle (114), and a first rotation position sensor (126) designed to detect movement of the first rotation position target marker (127) and to send a sensor signal to a control unit (121). [2] Steer-by-wire assembly (100) according to claim 1, further comprising a first gear transmission (128) configured to engage in rotation with the rotor carrier sleeve (111) and the first rotation position target marker (127), wherein the first sensor gear transmission (128) provides a reduction such that the first rotation position target marker (127) rotates more slowly than the rotor carrier sleeve (111). [3] Steer-by-wire assembly (100) according to claim 2, wherein the first rotation position target marker (127) is configured to rotate by less than 360° when the steering spindle (114) moves from a first fully turned position to a second fully turned position. [4] Steer-by-wire assembly (100) according to one of claims 1 or 2, further comprising a second rotational position target marker (130) arranged around the rotor carrier sleeve (111), wherein the combined position of both the second rotational position target marker (130) and the first rotational position target marker (127) uniquely corresponds to a position of the steering spindle (114). [5] Steer-by-wire setup (100) according to claim 4, further comprising a second rotary position sensor (129) configured to detect movement of the second rotary position target marker (130) and to send a sensor signal to the control unit (121). [6] Steer-by-wire assembly (100) according to one of claims 4 to 5, further comprising a second sensor gear transmission (131) configured to engage in rotation with the rotor carrier sleeve (111) and with the second rotation position target marker (130), wherein the second sensor gear transmission (131) provides a reduction such that the second rotation position target marker (130) rotates more slowly than the rotor carrier sleeve (111). [7] Steer-by-wire setup (100) according to claim 6, wherein the gear ratio of the second sensor gear ratio (131) differs from the gear ratio of the first sensor gear ratio (128). [8] Steer-by-wire assembly (100) according to one of claims 6 to 7, wherein the first sensor gear ratio (128) has a first prime number of teeth and the second sensor gear ratio (131) has a second prime number of teeth which differs from the first prime number of teeth. [9] Steer-by-wire assembly (100) according to any one of claims 1 to 8, further comprising a second motor (108) with a second stator (109) and a second rotor (110), wherein the second motor (108) is configured to supply additional rotational drive to the screw drive (117) in order to move the steering spindle (114) along the longitudinal axis (104). [10] Steer-by-wire assembly (100) according to any one of claims 1 to 9, wherein the screw drive (117) is selected from the group consisting of a ball screw drive and a roller screw drive. [11] Steer-by-wire setup (100) according to any one of claims 5 to 10, wherein the first rotary position sensor (126) and / or the second rotary position sensor (129) are selected from the group consisting of an optical encoder, a magnetic encoder, an inductive encoder, a capacitive encoder, a Hall effect sensor, a resolver, a potentiometer encoder and a cam follower. [12] Steer-by-wire assembly (100) according to any one of claims 4 to 11, wherein the first rotation position target marker (127) and / or the second rotation position target marker (130) are selected from the group consisting of a magnetic encoder, a patterned disk, a coded disk, a grid disk, a retroreflector disk, a slotted disk and a vernier scale disk. [13] Steer-by-wire assembly (100) according to any one of claims 6 to 8, wherein the first sensor gear ratio (128) and / or the second sensor gear ratio (131) are selected from a group consisting of planetary gears, harmonic gears, spur gears, bevel gears, worm gears and rack-and-pinion gears. [14] Steer-by-wire setup (100) according to any one of claims 1 to 13, wherein the control unit (121) is configured to determine the absolute position of the steering spindle (114) based on the sensor signals received from the first rotary position sensor (126) and / or sensor data received from the second rotary position sensor (129) using a reference table (124) stored in a memory (123). [15] Steer-by-wire setup (100) according to claim 14, wherein the control unit (121) is further configured to determine the absolute position of the steering spindle (114) based on detected unique rotational positions of both the first rotational position target marker (127) and the second rotational position target marker (130) using the vernier principle when signals are received from both the first rotational position sensor (126) and the second rotational position sensor (129). [16] Steer-by-wire setup (100) according to claim 14, wherein the control unit (121) is further configured to determine the absolute position of the steering spindle (114) based on the detected, unique angular position of the first rotation position target marker (127) when only the signal from the first rotation position sensor (126) is used. [17] Steer-by-wire assembly (100) according to one of the preceding claims, wherein the first rotational position target marker (127) and / or the second rotational position target marker (130) are arranged circumferentially around the rotor carrier sleeve (111). [18] Method for determining the absolute position of a steering spindle (114) in a steer-by-wire assembly (100), wherein the steer-by-wire assembly (100) comprises a first motor (105) with a first stator (106) and a first rotor (107), a lead screw drive configured to engage with a threaded section (120) of the steering spindle (114) and to move the steering spindle (114) longitudinally when the lead screw drive (117) rotates, and a rotor carrier sleeve (111) coupled between the first rotor (107) and the lead screw drive (117) and configured to rotate about the longitudinal axis (104) of the steering spindle (114), the method comprising: Detecting the position of the first rotary position target mark (127) with the first rotary position sensor (126), wherein the position of the first rotary position target mark (127) uniquely corresponds to a position of the threaded spindle (114), Received at the control unit (121) the detected sensor signal from the first rotary position sensor (126) and Determining the absolute position of the steering spindle based on the received sensor signal from the first rotary position sensor (126). [19] The method of claim 18, further comprising: Detecting the position of the second rotation position target marker (130) with the second rotation position sensor (129), Received at the control unit (121) the detected sensor signal from the second rotary position sensor (129) and Determining the absolute position of the steering spindle based on the detected unique combination of positions of both the first rotational position target mark (127) and the second rotational position target mark (130) using the vernier principle. [20] Absolute position sensor for a steer-by-wire assembly (100) comprising a first motor (105) with a first stator (106) and a first rotor (107), a lead screw drive (117) configured to mesh with a threaded section (120) of the steering spindle (114) and to move the lead screw drive (114) longitudinally when the lead screw drive (117) rotates, and a rotor carrier sleeve (111) coupled between the first rotor (107) and the lead screw drive (117) configured to rotate about the longitudinal axis (104) of the lead screw drive (114), wherein the absolute position sensor comprises: a first rotation position target marker (127) arranged around the rotor carrier sleeve (111) connected to a rotor of a motor, wherein the position of the first rotation position target marker (127) uniquely corresponds to a position of the steering spindle (114), and a first rotary position sensor (126) designed to detect movement of the first rotary position target marker (127) and to send a sensor signal to a control unit (121).

Images