Torque steering angle sensor for a steering system of a vehicle and method for operating the same

The torque steering angle sensor addresses the complexity and cost issues of separate torque and angle sensors by measuring both parameters simultaneously using a torsion spring and encoders, enhancing repair efficiency and reducing costs.

DE102023212124A1Pending Publication Date: 2025-06-05ROBERT BOSCH GMBH
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Patent Information

Application Number
DE102023212124
Authority / Receiving Office
DE · DE
Patent Type
Applications
Current Assignee / Owner
Filing Date
2023-12-04
Publication Date
2025-06-05

AI Technical Summary

Technical Problem

Existing vehicle steering systems require separate sensors for measuring steering torque and steering angle, which increases complexity and costs, and limits the ability to measure steering angle independently.

Method used

A torque steering angle sensor that combines the measurement of steering torque and steering angle by using a torsion spring to determine the torsion angle, which is then converted into steering torque and angle using encoders and decoders.

Benefits of technology

This solution allows for the simultaneous measurement of steering torque and angle, reducing the need for separate sensors and enabling more efficient repair and maintenance by allowing exchangeable sensor electronics.

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Abstract

The present invention relates to a torque steering angle sensor (100) for a steering system of a vehicle, wherein the torque steering angle sensor (100) has an input encoder (110), a torsion spring (108), an output encoder (112), at least one input decoder (114), at least one output decoder (118) and an electronics (122), wherein the input encoder (110) is coupled to an input shaft (104) of the steering system, which is rotatably mounted in a steering housing (102) of the steering system, and the output encoder (112) is coupled to an output shaft (106) of the steering system, which is rotatably mounted in the steering housing (102) axially to the input shaft (104), wherein the input shaft (104) and the output shaft (106) are twistably coupled to one another via the torsion spring (108), wherein the input decoder (114), the output decoder (118) and the electronics (122) are interchangeably and rotationally fixedly inserted radially to the input encoder (110) and the output encoder (112) in the steering housing (102).
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Description

Field of the invention

[0001] The invention relates to a torque steering angle sensor for a steering system of a vehicle, as well as a method for operating such a torque steering angle sensor. State of the art

[0002] A vehicle with a steering assistance device has a detection device for detecting a steering torque steered by a driver of the vehicle in order to be able to determine an assistance torque to be provided by an actuator in addition to the steering torque. The steering torque can be determined by a steering torque sensor. In particular, a torsion of a torsion spring caused by the steering torque can be measured in the steering torque sensor, and the steering torque can be calculated from a spring rate of the torsion spring. The torsion spring can be arranged between an input shaft of a steering column of the vehicle and an output shaft of the steering column within the steering torque sensor. A movable part of the steering torque sensor can be arranged on an input side of the torsion spring. The movable part can be rotatable with the input shaft. Another rotatable part of the steering torque sensor can be arranged on an output side of the torsion spring.The further part can be rotatable with the output shaft. Sensor electronics of the steering torque sensor can be arranged in a housing of the steering torque sensor.

[0003] The steering torque sensor can be based on MMT technology, for example. The first movable part comprises a permanent-magnetic magnetic ring with at least one pole pair consisting of a north pole and an adjacent south pole. The second movable part comprises two ferromagnetic magnetic guide rings, each with at least one coupling finger of a coupling finger pair. The magnetic guide rings can be aligned parallel to one another radially to the steering column. The sensor electronics can be arranged in a gap between the magnetic guide rings and have a ferromagnetic core for establishing a magnetic ring closure. A magnetic field sensor for detecting a magnetic field strength through the core can be arranged on the core.

[0004] The coupling fingers of the coupling finger pair are arranged next to each other, opposite the magnetic poles of the pole pair, and are moved relative to the pole pair by the torsion of the torsion spring. When one coupling finger is positioned centrally in front of the north pole and the other coupling finger is positioned centrally in front of the south pole, the maximum magnetic field strength is generated by the magnetic guide plates and the core. The further the coupling fingers are moved laterally away, the coupling of the respective magnetic pole decreases and the coupling of the other pole increases accordingly. The opposing magnetic fields weaken within the respective coupling finger. As a result, the total magnetic field strength coupled into the coupling fingers, magnetic guide rings, and the core decreases proportionally to the torsion.

[0005] The magnetic guide rings allow the sensor electronics to be fixed to the core. The magnetic field is coupled into the core regardless of the steering column's steering angle. The steering angle cannot be measured with the steering torque sensor.

[0006] EP 2 433 848 A2, for example, describes a three-part torque sensor system. Disclosure of the invention

[0007] Against this background, the approach presented here provides a torque steering angle sensor for a vehicle steering system, as well as a method for operating such a torque steering angle sensor according to the independent claims. Advantageous further developments and improvements of the approach presented here emerge from the description and are described in the dependent claims. Advantages of the invention

[0008] In the approach presented here, the torsion or twist of a torsion spring is determined from the difference between absolute angular positions at opposite ends of the torsion spring. The angular positions can also be measured at the ends of a partial section of the torsion spring. In the case of a steering system, the absolute angular positions also represent the current steering angle. The steering angle of a steering wheel can be measured at one end of the torsion spring, and the steering angle of a steering gear can be measured at the other end. Using a gear ratio of the steering gear and kinematic relationships, this steering angle can be converted into a steering angle or toe angle of the steered wheels.

[0009] Using the approach presented here, the sensor can simultaneously detect the steering torque applied via the steering wheel and the absolute steering angle of the steering gear and / or steering wheel via the spring rate of the torsion spring. Using the approach presented here, separate steering angle sensors and steering torque sensors can be dispensed with.

[0010] Because the sensor electronics are replaceable, repairs can be carried out in a specialist workshop with minimal effort, thus saving costs for materials, assembly and track adjustment.

[0011] According to a first aspect of the invention, a torque steering angle sensor for a steering system of a vehicle is presented, wherein the torque steering angle sensor has at least one input encoder, a torsion spring, at least one output encoder, at least one input decoder and at least one output decoder, wherein the input encoder is coupled to an input shaft of the steering system that is rotatably mounted in a steering housing of the steering system, and the output encoder is coupled to an output shaft of the steering system that is rotatably mounted in the steering housing axially to the input shaft, wherein the input shaft and the output shaft are twistably coupled to one another via the torsion spring, wherein the input decoder and the output decoder are interchangeably inserted in the steering housing radially or axially to the input encoder and the output encoder in a rotationally fixed manner.

[0012] According to a second aspect of the invention, a method for operating a torque steering angle sensor according to the first aspect is presented, wherein an input angle of the input shaft is detected using the input encoder rotatable with the input shaft and the input decoder arranged in a rotationally fixed manner in the steering housing, and an output angle of the output shaft is detected using the output encoder rotatable with the output shaft and the output decoder arranged in a rotationally fixed manner in the steering housing, wherein a torsion angle of the torsion spring is determined as the difference between the input angle and the output angle.

[0013] Ideas for embodiments of the present invention may be considered, among other things, to be based on the thoughts and findings described below.

[0014] A torque steering angle sensor based on the approach presented here can be used particularly in vehicles with steering assistance to determine a set steering angle and a steered steering torque. The vehicles can be single-track or multi-track vehicles and can cover all classes. The torque steering angle sensor can be installed in everything from bicycles to cars to special-purpose vehicles. The torque steering angle sensor can be referred to as a combined steering angle and steering torque sensor. The torque steering angle sensor can be integrated into a vehicle's steering column. The steering column can be divided into an input shaft and an output shaft at the torque steering angle sensor. The input shaft and the output shaft are connected by a twistable torsion spring. The torsion spring can, for example, be designed as a torsion bar.An input angle of the input shaft represents the angular position of a vehicle's steering wheel. An output angle of the output shaft represents the angular position of a vehicle's steering gear. The torsion angle represents the steering torque applied to the steering gear via the steering wheel.

[0015] An encoder is rotatable and provides scannable or measurable angular information over at least one full revolution. The angular information can in particular be absolute, meaning that angular positions of the encoder can be clearly distinguishable over the full 360° or over corresponding partial segments. A decoder receives, reads and / or measures this angular information or at least a section of the angular information and maps the angular position of the encoder represented in the angular information into an electrical signal. The encoder and decoder can in particular work together without contact. The decoder may require electrical energy to be able to provide the electrical signal. The angular information can be transmitted from the encoder to the decoder, for example, optically, magnetically, inductively, or capacitively. An encoder of the input shaft can be referred to as an input encoder.A decoder for the angular position of the input shaft can be called an input decoder. An encoder for the output shaft can be called an output encoder. A decoder for the angular position of the output shaft can be called an output decoder.

[0016] The input decoder and a section of the torque-steering angle sensor's electronics associated with the input decoder can be housed in a replaceable, pluggable input decoder housing. The output decoder and a section of the electronics associated with the output decoder can be housed in a replaceable, pluggable output decoder housing. The input decoder and the output decoder can be replaced independently of each other. In the event of a defect, only the defective component can be replaced.

[0017] The input decoder and output decoder can be housed in a common, replaceable, plug-in sensor housing. This common housing can be easily and safely replaced. Additional electronics for the torque / steering angle sensor can also be housed in the housing. A geometric anti-twist device or a pokajoke lock can prevent incorrect installation. The sensor housing can be sealed by at least one circumferential seal on the steering housing.

[0018] The input encoder and the output encoder can each have at least two magnetic tracks with consecutive pole pairs. The magnetic tracks can have different numbers of pole pairs. For example, the magnetic tracks can have 26 poles and 28 poles. Alternatively, the magnetic tracks can have five vernier segments, each with a segment length of 72° and 10 or 12 poles. Due to the different numbers of pole pairs, the encoders can have vernier coding. Due to the vernier coding, the combined magnetic field emanating from the magnetic tracks can be different for each angular position of the encoder and thus unique over the full 360°. Alternatively, the coding can be unique for sub-segments <360°.

[0019] The input decoder and the output decoder can each have at least one sensor element per magnetic track. Having more than one sensor element allows for redundancy in the event of a sensor element failure. In addition, error correction can be carried out using multiple sensor elements. By arranging the sensors at an angle, for example offset by 180°, external interference effects can have different effects on the redundant measuring points and can thus be compensated for. External interference effects can result, for example, from radial displacements caused by forces, bearing play, assembly tolerances, tolerances due to service replacement and / or EMC. With two or more sensor elements per magnetic track, the torque steering angle sensor can function without restrictions even if one sensor element fails. In addition, a sensor element that is detecting incorrectly can be detected and corrected.

[0020] The sensor elements of the input decoder and the output decoder can each be configured to map a magnetic field direction of a magnetic field emitted by the input encoder or output encoder and penetrating the respective sensor element into an electrical signal. The sensor elements can be AMR, GMR, or TMR sensors. The sensor elements can also be 3D Hall sensors.

[0021] At least one satellite gear engaging the input shaft or output shaft can be interchangeably inserted radially in the steering housing with a revolution sensor. The satellite gear and the revolution sensor can in particular be arranged or integrated in the shared sensor housing of the input decoder and output decoder. The satellite gear can count entire revolutions or entire sub-segments of the respective shaft. The satellite gear can extend the measuring range to >360°. This means that the absolute steering angle can be measured immediately even after an interruption in the power supply. A torque steering angle sensor with a satellite gear can be described as TPO (True Power On) capable. Alternatively, the input encoder and / or the output encoder can be indexed, i.e. have an additional marking or detectable point via which the entire revolutions can be counted.The torque steering angle sensor can have an additional indexing detection device. A counter value for the indexing can then be stored in the electronics or a connected control unit and overwritten each time the indexing is detected, taking into account the direction of rotation of the steering column.

[0022] The input decoder and the output decoder can be EMC shielded by a ferromagnetic shield. The shield can be coupled to the input encoder or the output encoder. The shield can therefore rotate with the encoders and the steering column. The shield can be arranged on both sides of the input encoder and the output encoder. The input decoder and the output decoder can be arranged in a space between the shields. This allows the input decoder and the output decoder to be shielded from two sides. Alternatively or additionally, the shield can be arranged in the sensor housing and inserted radially into the steering housing so that it can be interchangeable with the sensor housing. The sensor housing can be shielded on several sides. In particular, the sensor housing can be ring-shaped and circumferentially shielded. The rear side of the sensor housing, facing away from the encoders, can also be shielded.

[0023] At least one sensor element of the input decoder can be arranged on a first side of the input encoder. At least one further sensor element of the input decoder can be arranged on a second side of the input encoder, in particular diametrically opposite the first side. At least one sensor element of the output decoder can be arranged on a first side of the output encoder. At least one further sensor element of the output decoder can be arranged on a second side of the output encoder, in particular diametrically opposite the first side. The encoders can therefore be arranged substantially centrally between the at least two opposing sensor elements. Due to the opposing arrangement, angular tolerances and / or positional tolerances of the input shaft or the output shaft can have an amplifying effect on one sensor element and a weakening effect on the opposite sensor element.Through shared signal processing for both sensor elements, the effects of angular and / or positional tolerances can be mutually compensated. Due to the diametrical arrangement, external disturbances can have different signal effects, which can be compensated for in this way. Possible disturbances that can be compensated for include radial movements of the shaft due to, among other things, lateral forces and / or bearing play, EMC interference, assembly tolerances, and / or service replacement tolerances.

[0024] It should be noted that some of the possible features and advantages of the invention are described herein with reference to different embodiments. One skilled in the art will recognize that the features of the torque steering angle sensor and the method can be combined, adapted, or interchanged as appropriate to achieve further embodiments of the invention. Short description of the drawings

[0025] Embodiments of the invention will now be described with reference to the accompanying drawings, wherein neither the drawings nor the description are to be construed as limiting the invention. Fig. 1 shows a representation of a torque steering angle sensor according to an embodiment; Fig. 2 shows an illustration of an absolute torque steering angle sensor according to an embodiment; Fig. 3 shows a representation of a shielded torque steering angle sensor according to an embodiment; Fig. 4 shows an illustration of a split torque steering angle sensor according to an embodiment; Fig. 5 shows an illustration of an input and output encoder for a torque steering angle sensor according to an embodiment; Fig. 6 shows a diagram of a shielded input and output encoder for a torque steering angle sensor according to an embodiment; and Fig. 7 shows a representation of a segmented input and output encoder for a torque steering angle sensor according to an embodiment.

[0026] The figures are merely schematic and not to scale. Like reference numerals denote like or equivalent features. Embodiments of the invention

[0027] Fig. 1 shows a representation of a torque steering angle sensor 100 according to an exemplary embodiment. The torque steering angle sensor 100 is arranged in the region of a steering housing 102 of a vehicle's steering system. A steering column of the steering system runs through the steering housing 102. The steering column is divided into an input shaft 104 and an output shaft 106 in the region of the steering housing 102. The input shaft 104 comes from a steering wheel of the vehicle. The output shaft 106 leads, for example, to a steering gear of the steering system. The input shaft 104 and the output shaft 106 are rotatably mounted in the steering housing and axially aligned. The input shaft 104 and the output shaft 106 are coupled to one another within the steering housing 102 by a torsion spring 108 of the torque steering angle sensor 100. The torsion spring 108 is arranged coaxially with the input shaft 104 and the output shaft 106. Here, the torsion spring 108 is designed as a torsion bar.

[0028] In addition to the torsion spring 108, the torque steering angle sensor 100 has an input encoder 110 coupled at an angle to the input shaft 104, an output encoder 112 coupled at an angle to the output shaft 106, an input decoder 114 coupled to the steering housing 102 for detecting an input angle 116 of the input encoder 110, an output decoder 118 coupled to the steering housing 102 for detecting an output angle 120 of the output encoder 112, and electronics 122 for processing the signals of the input decoder 114 and the output decoder 118.

[0029] The input encoder 110 and the output encoder 112 are designed as angular embodiments of the input angle 116 and the output angle 120, respectively. The input angle 116 and the output angle 120 are each uniquely coded over a full rotation or over the full 360°. The input decoder 114 and the output decoder 118 can therefore decode a unique value for each angular position of the input encoder 110 and the output encoder 112, respectively. The input angle 116 and the output angle 120 can be decoded with an accuracy of less than 0.1°.

[0030] When a torque 124 is applied via the steering wheel and the input shaft 104, the torsion spring 108 transmits this torque 124 to the output shaft 106. The output shaft 106 then transmits the torque 124 to the steering gear. The torque 124 twists the torsion spring 108, i.e., the ends of the torsion spring 108 fixed to the input shaft 104 and output shaft 106 are axially rotated relative to each other. A torsion angle 126 of the torsion spring 108 depends on a spring rate, i.e., an elasticity or stiffness of the torsion spring 108, and the torque 124. The torsion angle 126 is proportional to the torque 124. Since the input encoder 110 and the output encoder 112 are angularly coupled to the input shaft 104 and the output shaft 106, respectively, the input encoder 110 is rotated by an angle greater than the output encoder 112 by the torsion angle 126.

[0031] The input decoder 114 detects the angular position of the input encoder 110 as input angle 116, and the output decoder 118 detects the angular position of the output encoder 112 as output angle 120. In the electronics 122, a difference between the input angle 116 and the output angle 120 is determined. The difference corresponds to the torsion angle 126. Using the known spring rate of the torsion spring 108, the torque 124 is calculated from the torsion angle 126.

[0032] The input decoder 114, the output decoder 118, and the electronics 122 are arranged together in a sensor housing 128 inserted radially into the steering column in the steering housing 102. The sensor housing 128, containing the input decoder 114, the output decoder 118, and the electronics 122, is replaceable. The sensor housing 128 has a connector 130 on its outer side for connecting a data line to a control unit.

[0033] The input encoder 110 and the output encoder 112 are disc-shaped and aligned transversely to the input shaft 104 and the output shaft 106, respectively. The input decoder 114 and the output decoder 118 are arranged radially to the input encoder 110 and the output encoder 112, respectively. The input decoder 114 and the output decoder 118 do not touch the input encoder 110 and the output encoder 112, respectively.

[0034] In one embodiment, the input encoder 110 and / or the output encoder 112 has an indexing in addition to the angle representation. The indexing uniquely marks an angular position of the input encoder 110 or output encoder 112, respectively. This angular position represents a reference point of the steering. To detect the indexing, the torque steering angle sensor 100 has a detection device arranged in the sensor housing 128. The detection device outputs a signal pulse when the indexing moves past the detection device. Taking into account a direction of rotation of the steering column, revolutions of the steering column can be counted using the indexing and the associated detection device and stored in the control unit in order to store an absolute steering angle of the steering wheel.

[0035] Fig. Figure 2 shows an illustration of an absolute torque steering angle sensor 100 according to an embodiment. The torque steering angle sensor 100 essentially corresponds to the torque steering angle sensor in Fig. 1. In addition, the torque steering angle sensor 100 has a satellite gear 200. The satellite gear 200 engages a gear ring 202 on the output shaft 106. The gear ring 202 is angularly connected to the output shaft 106. When the output shaft 106 rotates, the satellite gear 200 is also rotated. The satellite gear 200 reduces the speed of the output shaft 106 with a defined reduction ratio. A rotation sensor 204 is arranged at an output of the satellite gear 200. The rotation sensor 204 outputs a value indicating how many times the output shaft 106 has rotated in one direction.

[0036] Fig. Figure 3 shows a representation of a shielded torque steering angle sensor 100 according to an embodiment. The torque steering angle sensor 100 essentially corresponds to the torque steering angle sensor in Fig. 1. In addition, the torque steering angle sensor has a shield 300. The shield is made of a ferromagnetic material and is designed to shield the input decoder 114 and the output decoder 118 from electromagnetic coupling by electromagnetic fields. Here, the shield 300 is arranged in the sensor housing 128. The shield 300 protrudes from the sensor housing 128 and partially overlies the input encoder 110 and the output encoder 112.

[0037] Fig. Figure 4 shows a representation of a split torque steering angle sensor 100 according to an embodiment. The torque steering angle sensor 100 essentially corresponds to the torque steering angle sensor in Fig. 1. In contrast, the input decoder 114 is arranged in an input decoder housing 400. The output decoder 118 is arranged in an output decoder housing 402. The part of the electronics 122 required for evaluating the input decoder 114 and the output decoder 118, respectively, is arranged in the input decoder housing 400 and the output decoder housing 402. The input decoder housing 400 and the output decoder housing 402 are each inserted into the steering housing 102 in the radial direction of the steering column and can be replaced individually. The input decoder housing 400 and the output decoder housing 402 each have a connector 130 for connecting to the control unit.

[0038] Fig. Figure 5 shows an illustration of an encoder 500 for a torque steering angle sensor according to an embodiment. The encoder 500 essentially corresponds to the input encoder and the output encoder from the Fig. 1 to 4. Here, the encoder has two parallel, ring-shaped magnetic tracks 502. The magnetic tracks 502 are the same size and have a vernier coding. For this purpose, one magnetic track has 13 pole pairs, each consisting of a north pole and a south pole, or 26 poles. The other magnetic track 502 has 14 pole pairs, or 28 poles. Due to the different numbers of magnetic poles 504, each magnetic pole 504 results in a different lateral displacement of the magnetic poles 504 of the two magnetic tracks 502 relative to one another. The displacement is different for each magnetic pole 504 and therefore unique. Both magnetic tracks 502 are scanned simultaneously by the associated decoder. From the individual displacement of the magnetic poles 504, the decoder can unambiguously detect the current angular position of the encoder 500 for each angular position of the encoder 500.

[0039] Fig. Figure 6 shows a representation of a shielded encoder 500 for a torque steering angle sensor 100 according to an embodiment. The encoder 500 essentially corresponds to the encoder in Fig. 5. In addition, the encoder 500 has a shield 300. The shield 300 is designed as ferromagnetic rings that surround both sides of the encoder 500. The rings are arranged on a flat top side of the encoder 500 and a flat bottom side of the encoder 500. The shield is arranged parallel to the magnetic tracks 502. The rings have a larger diameter than the magnetic tracks 502. The associated encoder is then arranged between the rings and is thus well protected from electromagnetic interference.

[0040] Fig. Figure 7 shows a representation of a segmented encoder 500 for a torque steering angle sensor according to an embodiment. The encoder 500 essentially corresponds to the encoder in Fig. 5. Additionally, the encoder 500 is divided into segments 700. Here, the encoder 500 has five segments 700, each with an angle of 72°. The segments 700 are identical. The magnetic tracks 502 have 10 or 12 magnetic poles 504 per segment. The resulting vernier coding of the encoder 500 is thus repeated five times per revolution. Across the entire circumference, the magnetic tracks 502 thus have 50 magnetic poles 504 or 60 magnetic poles 504. Using a satellite wheel, uniqueness greater than one segment 700 or across multiple segments 700 can be achieved.

[0041] In the following, possible embodiments of the invention are summarized again or presented with slightly different wording.

[0042] A serviceable magnet-based radial-off-shaft torque-angle sensor is presented.

[0043] Current sensor electronics in electric steering systems cannot be replaced as individual components over the product life cycle and are therefore not serviceable. In the event of sensor defects, the sensor electronics must be replaced along with the entire steering system. This results in significant costs. The replaceable sensor electronics presented here can extend the service life of the steering system and minimize costs through predictable service intervals. The replaceable sensor electronics can be used to expand a maintenance program.

[0044] Serviceability refers to the possibility of replacing sensors without having to replace the entire steering system.

[0045] The replaceability of the sensor electronics ensures the functionality of the steering system, reducing the time required for repairs and lowering the repair costs for the end customer. Furthermore, zero-mileage steering failures can be repaired more cost-effectively, as the entire steering system does not need to be replaced. Furthermore, replacing only the defective sensor component of a steering system improves sustainability.

[0046] The figures show the basic design of the sensor, based on a torsion bar / torsion bar principle. The input and output shafts are connected via a torsion bar / torsion bar; by measuring the relative torsion between the two, the torque can be calculated.

[0047] Magnetic pole rings are attached to both the input and output shafts, allowing a 360° absolute angle to be calculated. To enable this, each magnetic pole ring has two differently spaced magnetic pole tracks with 360° vernier coding. One possible implementation of the magnetic pole ring is 26 or 28 poles for 360° vernier coding. The difference between the two absolute angles of the input shaft and output shaft can be used to determine the relative torsion between the two and thus the torque. Individual or redundant 360° magnetic field sensors using AMR, GMR, TMR, or 3D Hall technology are used to scan the magnetic tracks of the magnetic pole rings. The magnetic field sensors are adapted or optimized according to the pole pitch of the magnetic pole rings.

[0048] Sensor variants with three or more tracks are also conceivable. This enables the construction of a redundant or fault-tolerant sensor system.

[0049] A TPO true power-on steering angle can be implemented by implementing an additional satellite wheel (or multiple satellite wheels) on the input and / or preferably on the output shaft. This allows the steering angle range to be extended to a corresponding multiple of 360°. With a non-true power-on steering angle solution, the input or preferably on the output shaft can have a 360° period (indexing), which can be used to reference the steering center at the steering system level. The steering angle information comes from an evaluating control unit.

[0050] Sensor variants as pure TPO True Power-On or index-based torque steering angle sensors are also possible, in which case one of the magnetic pole rings can be omitted.

[0051] The ASICs are an essential part of the sensor; they process measurement signals and output the measured variables via an electrical interface to the evaluating control unit. In the approach presented here, a housing carries all the sensor components, including the ASIC(s). The enclosed design can be mounted radially from the outside into the steering housing, allowing for serviceability—meaning the sensor can be replaced in the field throughout the product's life cycle. Alternatively, the sensors for scanning the pole wheels can be mounted individually from the outside, allowing them to be replaced individually.

[0052] In one embodiment, the sensors for scanning the magnetic tracks are shielded against EMC influences by being arranged between two ferromagnetic elements. The EMC shielding elements can be arranged on the magnetic pole rings and / or in the sensor housing.

[0053] The approach presented here can be used in electronic steering systems of cars and commercial vehicles (construction, agricultural machinery) for torsion bar-based torque measurement and / or angle measurement and / or linear displacement measurement of all kinds in industry (manufacturing), bicycles and consumer sectors.

[0054] Finally, it should be noted that terms such as "comprising," "having," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Reference signs in the claims are not to be considered limiting. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0000] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> EP 2 433 848 A2

[0006]

Claims

[1] Torque steering angle sensor (100) for a steering system of a vehicle, wherein the torque steering angle sensor (100) has an input encoder (110), a torsion spring (108), an output encoder (112), at least one input decoder (114) and at least one output decoder (118), wherein the input encoder (110) is coupled to an input shaft (104) of the steering system, which is rotatably mounted in a steering housing (102) of the steering system, and the output encoder (112) is coupled to an output shaft (106) of the steering system, which is rotatably mounted in the steering housing (102) axially to the input shaft (104), wherein the input shaft (104) and the output shaft (106) are twistably coupled to one another via the torsion spring (108), wherein the input decoder (114) and the output decoder (118) are interchangeably and rotationally fixedly inserted radially to the input encoder (110) and the output encoder (112) in the steering housing (102). [2] Torque steering angle sensor (100) according to claim 1, wherein the input decoder (114) is arranged in an interchangeably pluggable input decoder housing (400), wherein the output decoder (118) is arranged in an interchangeably pluggable output decoder housing (402). [3] Torque steering angle sensor (100) according to claim 1, wherein the input decoder (114) and the output decoder (118) are arranged in a common interchangeable pluggable sensor housing (128). [4] Torque steering angle sensor (100) according to one of the preceding claims, wherein the input encoder (110) and the output encoder (112) each have at least two magnetic tracks (502) with consecutive pole pairs, wherein the magnetic tracks (502) have different numbers of pole pairs, wherein the input decoder (114) and the output decoder (118) each have at least one sensor element per magnetic track (502). [5] Torque steering angle sensor (100) according to claim 4, wherein the magnetic tracks each have at least two segments (700) with different numbers of pole pairs. [6] Torque steering angle sensor (100) according to one of the preceding claims, in which sensor elements of the input decoder (114) and of the output decoder (118) are each designed to map a magnetic field direction of a magnetic field emitted by the input encoder (110) or output encoder (112) and penetrating the respective sensor element in a respective electrical signal. [7] Torque steering angle sensor (100) according to one of the preceding claims, wherein at least one satellite gear (200) with a rotation sensor (204) is interchangeably inserted radially in the steering housing (102). [8] Torque steering angle sensor (100) according to one of the preceding claims, wherein the input decoder (114) and the output decoder (118) are shielded by a ferromagnetic shield (300). [9] Torque steering angle sensor (100) according to claim 8, wherein the shield (300) is coupled to the input encoder (110) or the output encoder (112). [10] Torque steering angle sensor (100) according to claim 3 and one of claims 8 to 9, wherein the shield (300) is arranged in the sensor housing (128) and is plugged radially into the steering housing (102) so as to be replaceable with the sensor housing (128). [11] Torque steering angle sensor (100) according to one of the preceding claims, wherein at least one sensor element of the input decoder (114) is arranged on a first side of the input encoder (110) and at least one further sensor element of the input decoder (114) is arranged on a second side of the input encoder (110) opposite the first side, wherein at least one sensor element of the output decoder (118) is arranged on a first side of the output encoder (112) and at least one further sensor element of the output decoder (118) is arranged on a second side of the output encoder (112) opposite the first side. [12] A method for operating a torque steering angle sensor (100) according to one of the preceding claims, wherein an input angle (116) of the input shaft (104) is detected using the input encoder (110) rotatable with the input shaft (104) and the input decoder (114) arranged in a rotationally fixed manner in the steering housing (102), and an output angle (120) of the output shaft (106) is detected using the output encoder (112) rotatable with the output shaft (106) and the output decoder (118) arranged in a rotationally fixed manner in the steering housing (102), wherein a torsion angle (126) of the torsion spring (108) is determined as the difference between the input angle (116) and the output angle (120).

Citation Information

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