Sensor unit and arrangement for detecting the position of a component

Abstract

Sensor unit (300) for detecting the position (φ) of a component (2), wherein the sensor unit (300) comprises: - at least six magnetically sensitive elements arranged in a measuring plane (200), each of which is designed to detect a magnetic field (20) exclusively along a measuring direction (206) extending orthogonally to the measuring plane (200), and - an evaluation unit (40) connected to the magnetically sensitive elements of the sensor unit (300) and designed to determine a position signal (44) corresponding to the position (φ) of the component (2) based on the signals from a first sensor element pair (301) of magnetically sensitive elements and / or based on the signals from a second sensor element pair (303) of magnetically sensitive elements, wherein the evaluation unit (40) comprises: - a first selection unit (52) designed toto establish a connection to the selectable magnetically sensitive elements of the first sensor element pair (301), and- a second selection unit (54) which is designed to establish a connection to the selectable magnetically sensitive elements of the second sensor element pair (303).

Description

[0001] The present invention relates to a sensor unit and an arrangement for detecting the position of a component, in particular a sensor unit and an arrangement for contact-free detection of an angular position of a rotor of an electric motor or a valve flap rotatable about a rotational axis or a rotational axis of an actuator.

[0002] The use of magnetically based angle sensors is known for detecting the angular position of a component rotatable about a rotational axis. GB 2 505 226 A, for example, discloses an arrangement, a method, and a sensor for measuring an angular position using a multipole magnet with compensation for magnetic interference / external fields. The arrangement disclosed therein comprises a multipole pair magnet attached to a rotor and a stationary sensor. The sensor comprises several sensor elements arranged in a circle, which are essentially arranged in two groups for measuring the magnetic field components acting parallel to the sensor plane. The arrangement disclosed therein allows homogeneous magnetic interference / external fields to be compensated to a large extent.However, with the segmented multi-pole pair magnet, the usable angle measuring range is limited so that only a range of 360° divided by the number of pole pairs of the magnet can be measured.

[0003] Furthermore, devices for detecting the angular position of a rotatable component are known from EP 0 916 074 B1, US 2015 / 0 276 893 A1, DE 10 2015 001 553 B3, DE 10 2014 005 247 A1, DE 10 2004 064 185 B4, and DE 698 16 755 T2. These disclosures are also based on differential calculation to suppress magnetic interference / extraneous fields. Parallel components of the magnetic field are detected, and therefore only those magnetic field components that act orthogonally to the sensor plane are measured. Magnetically sensitive sensors, such as magnetoresistive sensors or vertical Hall cells, which measure parallel to the sensor plane, cannot be used.

[0004] DE 10 2009 042 473 A1 discloses a method for evaluating signals from an angle sensor having at least two sensor elements spanning a plane and having a rotatable element spaced from this plane for varying a field, as well as a brushless electric motor controlled by this method. In order to specify a method for evaluating signals from an angle sensor having at least two sensor elements that produces high-resolution measurement results with sensor elements that map a full circle, the sensor elements detect at least a first and a second linearly independent vector of the field present in this plane, wherein a further variable is additionally detected that is dependent on the distance between the plane and the rotatable element, and wherein the amplitudes of the signals from the first and second sensor elements are controlled with the magnitude of the further variable.

[0005] DE 10 2016 202 378 A1 discloses an arrangement that can at least partially compensate for magnetic interference / external fields. However, the arrangement disclosed therein may exhibit excessive measurement inaccuracies due to geometric tolerances of the individual components, which may be assembly-related and / or material-related.

[0006] WO 2016 / 139 135 A1 relates to a method and an arrangement for determining the position of a magnetic body using one or more magnetic field sensors, which moves relative to the one or more magnetic field sensors. In the method, one or more of three directional components of the magnetic flux density of the magnetic field generated by the magnetic body are repeatedly locally detected and evaluated using the magnetic field sensors in order to determine the respective position of the magnetic body. The magnetic field sensors are arranged in the near field of the magnetic body. The evaluation is carried out at least partially using an optimal estimator based on a magnetic field model. Using the method and the associated arrangement, up to six mechanical degrees of freedom of the magnetic body can be determined in a very small space.

[0007] EP 1 668 378 B1 discloses a sensor for detecting the direction of a magnetic field in a plane. The sensor known therefrom comprises several magnetic field sensors and logic and evaluation circuits. Each magnetic field sensor is assigned a measuring axis such that the absolute value of the output signal of the magnetic field sensor is greatest when the magnetic field runs parallel to the assigned measuring axis.

[0008] DE 103 20 057 A1 describes a redundant angle sensor with Hall effect elements, which has eight horizontal Hall sensor structures on a semiconductor substrate, which can consist of one or more individual elements.

[0009] US 2002 / 0 021 124 A1 discloses a sensor for detecting the direction of a magnetic field, comprising a single magnetic field concentrator with a flat shape and at least a first horizontal Hall-effect element and a second horizontal Hall-effect element. The Hall-effect elements are arranged in the region of an edge of the magnetic field concentrator.

[0010] DE 10 2005 039 280 A1 describes an integrated circuit with magnetic field sensors, in which structures for at least two magnetic field-sensitive sensor elements and electronic components are applied on the same substrate.

[0011] Magnetic interference / external fields can be generated by nearby permanent magnets, electromagnets, or even by a nearby power line. With the electrification of vehicles, especially with regard to the 48-volt electrical system, for example, where currents of over 1,000 amperes can occur, or due to magnets installed nearby, the magnetic field source is increasingly subject to magnetic interference / external fields, which can influence the sensor signal and thus negatively distort the measurements of the magnetic encoder.

[0012] The object of the present invention is to provide a sensor unit and an arrangement with which the position of a component can be detected reliably, as accurately as possible and, in the case of a component rotating about a rotational axis, over an angular measuring range of 360° and which are robust against magnetic interference / external fields and against geometric tolerances.

[0013] This object is achieved with the sensor unit according to independent claim 1. Advantageous embodiments are specified in the subclaims.

[0014] The present invention is essentially based on the idea of ​​providing a sensor unit and an arrangement for detecting the position of a moving (translationally and / or rotationally) component, in which a plurality of magnetically sensitive elements are arranged such that, after positioning relative to a magnet or a ferromagnetic component, at least one sensor element pair consisting of two magnetically sensitive elements can be selected that are arranged most favorably with regard to measurement accuracy. In particular, the selected magnetically sensitive elements are arranged most favorably with regard to displacements caused by geometric tolerances.

[0015] When detecting the angular position of a component that can rotate about a rotational axis, for example, two pairs of sensor elements are selected whose magnetically sensitive elements are arranged most favorably in terms of measurement accuracy when they are arranged equidistantly on a circle around a center point that is closest to the rotational axis. Thus, the distances of the magnetically sensitive elements of the two pairs of sensor elements from the rotational axis are essentially similar, preferably essentially the same. When detecting the position of a component that can move along a movement path, those magnetically sensitive elements of a pair of sensor elements are arranged most favorably in terms of measurement accuracy when they output the greatest value for the detected magnetic field.

[0016] According to the invention, a sensor unit for detecting the position of a component is thus provided, which has at least six magnetically sensitive elements arranged in a measuring plane, each of which is designed to detect a magnetic field exclusively along a measuring direction extending orthogonally to the measuring plane, and an evaluation unit which is connected to the magnetically sensitive elements of the sensor unit and is designed to determine a position signal corresponding to the position of the component based on the signals from a first sensor element pair of magnetically sensitive elements and / or based on the signals from a second sensor element pair of magnetically sensitive elements.

[0017] The evaluation unit comprises a first selection unit configured to establish a connection to the selectable magnetically sensitive elements of the first sensor element pair, and a second selection unit configured to establish a connection to the selectable magnetically sensitive elements of the second sensor element pair. The two selection units are therefore preferably configured to select the magnetically sensitive elements with which the position of the component is to be determined. This selection is preferably made only once, after assembly with a magnet.

[0018] By arranging several, at least six, magnetically sensitive elements in the measuring plane, the two or four magnetically sensitive elements can be selected to detect the position of the component, which enable the most accurate detection of the component's position despite the existing offset between the sensor unit and the component due to geometric tolerances and acting magnetic interference / external fields. Once the relative positioning between the sensor unit and the component is complete and remains unchanged, a one-time selection, for example, by a non-volatile memory device, of the magnetically sensitive elements intended for the measurement is revealed.

[0019] For this purpose, the signals of the two or four magnetically sensitive elements with which the error in the determined position of the component is the smallest are used. In particular, two pairs of magnetically sensitive elements form a sensor grouping that can detect the angular position of a component rotatable about a rotational axis.

[0020] If, for example, one of the several magnetically sensitive elements outputs a value of approximately zero for the magnetic field component running parallel to the axis of rotation, four magnetically sensitive elements are detected around this one magnetically sensitive element, which lie on the circumference of a circle whose center lies on the one magnetically sensitive element that outputs the value of approximately zero for the magnetic field component running parallel to the axis of rotation. However, if the magnetically sensitive elements of a sensor pair each output similar values ​​for the magnetic field components running parallel to the axis of rotation, then precisely these four magnetically sensitive elements are detected. These four magnetically sensitive elements are then arranged equidistantly on the circumference of a circle whose center lies inside an imaginary square, at whose vertices precisely these four magnetically sensitive elements are arranged.

[0021] In a preferred embodiment of the sensor unit according to the invention, the signals of all magnetically sensitive elements are detected, and those magnetically sensitive elements that each output the largest value in terms of magnitude are defined as belonging to the first sensor element pair of magnetically sensitive elements, and / or those magnetically sensitive elements that each output the largest value in terms of magnitude are defined as belonging to the second sensor element pair of magnetically sensitive elements. Additionally or alternatively, in a sensor unit designed to detect the angular position of the component, a predetermined diameter can be defined for the circle, and those magnetically sensitive elements whose signals are each essentially symmetrical in terms of magnitude during a full circle rotation can be selected.

[0022] In this preferred embodiment, it is advantageous if the sensor element pairs are selected without the influence of external magnetic / interference fields.

[0023] In an advantageous embodiment, the sensor unit is designed to determine an angle signal corresponding to the angular position of the component rotating about a rotational axis based on the signals from those four magnetically sensitive elements of the first and second sensor element pair, which are each arranged equidistant from one another on a circumference of a circle around a center point which is closest to the rotational axis in the measuring plane.

[0024] The two magnetically sensitive elements of each sensor element pair are then arranged opposite each other on the circumference of the circle. The radius of the circle is preferably as large as possible, which at least partially reduces the influence of geometric tolerances.

[0025] Because the influence of geometric tolerances decreases with larger circle diameters, but the sensor unit becomes more sensitive to inhomogeneous magnetic interference / external fields if these have curved field lines (e.g., a power cable near the sensor unit), it may be preferable to increase the density of the magnetically sensitive elements with decreasing radius. This means that more magnetically sensitive elements are arranged on the sensor unit in the closer vicinity to the axis of rotation than in a more distant area. The smaller the diameter of the circle on which the magnetically sensitive elements intended for measurement are arranged, the less influence inhomogeneous magnetic interference / external fields have, which in turn can result in a greater sensitivity to geometric tolerances.

[0026] Furthermore, it may be preferable for the center of the circle to be determined by determining the center closest to the magnetically sensitive element that outputs the smallest value in terms of magnitude. Consequently, after determining the magnetically sensitive element that outputs the smallest value in terms of magnitude, the magnetically sensitive elements of the two sensor element pairs can be determined such that they are equally spaced from this then centrally arranged magnetically sensitive element.

[0027] In a further advantageous embodiment, the magnetically sensitive elements are arranged at least partially along a first axis running in the measuring plane and / or at least partially along at least one second axis running in the measuring plane parallel to the first axis, each equidistant from one another.

[0028] Preferably, the magnetically sensitive elements arranged on the first axis and / or the magnetically sensitive elements arranged on the at least one second axis are each further arranged on at least one third axis extending in the measuring plane at a predetermined angle to the first axis. Even more preferred is when the at least six magnetically sensitive elements are arranged in a matrix-like manner with at least two rows and at least three columns.

[0029] It may be preferred that one magnetically sensitive element of the first sensor element pair is arranged on the first axis, and the other magnetically sensitive element of the first sensor element pair is arranged on the at least one second axis. Alternatively or additionally, one magnetically sensitive element of the second sensor element pair is arranged on the first axis, and the other magnetically sensitive element of the second sensor element pair is arranged on the second axis.

[0030] Furthermore, it may be preferred that the magnetically sensitive elements of the first sensor element pair are arranged on the first axis and the magnetically sensitive elements of the second sensor element pair are arranged on the at least one third axis, wherein the first axis runs as a perpendicular bisector to the magnetically sensitive elements of the second sensor element pair and the third axis runs as a perpendicular bisector to the magnetically sensitive elements of the first sensor element pair.

[0031] In a preferred embodiment, the evaluation unit further comprises a non-volatile memory device designed to store the selection of the selected magnetically sensitive elements of the first and / or second sensor element pair made by the first selection unit and / or second selection unit in a non-volatile manner. This means that after the selection of the magnetically sensitive elements selected for detecting the position of the component has been made by the selection units, the switching positions of the selection units are stored once and permanently, even when the entire sensor unit is switched off. Thus, when the sensor unit is switched on again, this selection is available again so that the position of the component can be detected again as accurately as possible.

[0032] According to a further aspect, an arrangement for detecting the position of a component is disclosed, comprising a magnet configured to generate a magnetic field and a sensor unit according to the invention. The sensor unit is arranged at a distance from the magnet and configured to detect the magnetic field along a measuring direction extending orthogonally to the measuring plane and to determine therefrom a position signal corresponding to the position of the component.

[0033] Advantageously, the magnet or the sensor unit is arranged to be rotatable about a rotation axis and the sensor unit is designed to detect the magnetic field along the measuring direction and to output therefrom an angle signal corresponding to an angular position of the component.

[0034] In an alternative advantageous embodiment, the magnet or the sensor unit is arranged to be movable along a movement path and the sensor unit is designed to detect the magnetic field along the measuring direction and to determine therefrom a position signal corresponding to the path position of the component.

[0035] The component can be a separate component coupled to the magnet or the sensor unit. The component can, for example, be formed integrally with the magnet or can be a ferromagnetic element. A ferromagnetic element can, for example, be designed to modify the magnetic field of a stationary magnet.

[0036] Further objects and features of the arrangement according to the invention will become apparent to those skilled in the art upon practicing the present teachings and viewing the accompanying drawings in which: Fig. 1 shows a schematic view of an exemplary arrangement for detecting the angular position of a component rotatable about a rotation axis, which has a sensor unit according to the invention, Fig. 2 shows a schematic view of a sensor unit according to the invention connected to an exemplary evaluation unit, Fig. 3 a plan view of the sensor unit according to the invention of Fig. 2, in which exemplary selected magnetically sensitive elements are marked, Fig. 4 a plan view of the sensor unit according to the invention of Fig. 2, in which other exemplary selected magnetically sensitive elements are marked, Fig. 5 shows a plan view of another sensor unit according to the invention, Fig. 6 shows a plan view of another sensor unit according to the invention, in which exemplary selected magnetically sensitive elements are marked, Fig. 7 shows a plan view of another sensor unit according to the invention, with which a travel position of a component can be detected and selected magnetically sensitive elements are marked by way of example, Fig. 8 a top view of the sensor unit of the Fig. 7 shows, with which a path position of a component can be detected and other selected magnetically sensitive elements are marked as examples, and Fig. 9 shows a plan view of yet another exemplary sensor unit with which a path position and / or an angular position of a component can be detected and exemplary selected magnetically sensitive elements are identified.

[0037] Elements of the same design or function are identified by the same reference symbols throughout the figures. For reasons of clarity, not all elements are identified by reference symbols in all figures shown.

[0038] The description of the Fig. 1 to 6 illustrates the detection of an angular position of a component that can be rotated about a rotation axis. The description of the Fig. 7 to 9, however, explain by way of example the detection of a path position of a component moving along a linear path. However, it is expressly stated that the Fig. 1 to 6 are each also suitable for detecting the position of a component moving along a linear path. Likewise, the sensor unit of the Fig. 9 suitable for detecting the angular position of a component rotating about a rotation axis.

[0039] In the exemplary embodiments illustrated in the drawings, it is assumed, for example, that a magnet moves together with the component whose position is to be detected by the sensor unit according to the invention, and that the sensor unit according to the invention is arranged immovably and stationary relative to the component (and magnet). Alternatively, however, the sensor unit can also rotate together with the component, in which case the magnet is arranged immovably and stationary relative to the component.

[0040] The Fig. 1 shows an exemplary arrangement 1 for detecting the angular position φ of a component 2 rotatable about a rotational axis 100. The rotatable component 2 can be, for example, a shaft of a rotor of a DC motor. In further embodiments of the arrangement 1, the rotatable component 2 can be a throttle valve shaft of a throttle valve support of an internal combustion engine or an actuator for mechanical adjustment. In yet further embodiments, the rotatable component 2 can be formed integrally with the magnet 10 or can be a ferromagnetic element. A ferromagnetic element can, for example, be designed to change the magnetic field of a stationary magnet.

[0041] Order 1 of the Fig. 1 comprises a magnet 10 which is designed to generate a substantially symmetrical magnetic field 20. In the Fig. 1, the magnetic field lines of the magnetic field 20 are shown schematically. As in the Fig. 1, the magnet 10 has two poles, namely a north pole 12 and a south pole 14. In particular, the magnetic field 20 is symmetrical to the separation plane between the north pole 12 and the south pole 14. The component 2 is coupled to the magnet 10 and rotatable about the rotation axis 100 (see arrow 4 in the Fig. 1).

[0042] The Fig. The arrangement 1 shown in Figure 1 further comprises a sensor unit 300 according to the invention, which is spaced apart from the magnet 10. The sensor unit 300 is, for example, a sensor chip and is magnetically sensitive in a measuring direction 206 that runs orthogonal to a measuring plane 200 spanned by a first axis (or first direction) 202, for example, an x-axis, and a second axis (or second direction) 204, for example, a y-axis, that runs orthogonal to the first axis 202. Consequently, the predetermined angle α between the first axis 202 and the second axis 204 is 90° in the embodiment shown. The two axes 202, 204 are each arranged orthogonally to the axis of rotation 100, so that the measuring plane 200 of the sensor unit 300 consequently runs substantially orthogonally to the axis of rotation 100. In other embodiments, the angle α may take any angle other than 90°, for example 120°.

[0043] The sensor unit 300 is designed to be magnetically sensitive to magnetic field components that run orthogonal to the measuring plane 200 and thus parallel to the measuring direction 206. The sensor unit 300 is further designed to be non-magnetically sensitive to magnetic field components that run parallel to or in the measuring plane 200.

[0044] The sensor unit 300 is in the Fig. 1 and is designed to detect the magnetic field 20 of the magnet 10 rotating together with the component 2 and to output therefrom an angle signal 44 corresponding to the angular position φ of the component 2.

[0045] The sensor unit 300 of the Fig. For reasons of simplicity, Figure 1 is shown with only four magnetically sensitive elements 302, 304, 306, 308, although it is expressly stated here that an arrangement 1 according to the invention has at least six magnetically sensitive elements. For the purpose of explaining the evaluation of the signals from four magnetically sensitive elements for determining the angular position of the rotatable component 2, Fig. 1 only four magnetically sensitive elements 302, 304, 306, 308 are shown.

[0046] In the following, with reference to the Fig. 1 describes the measuring principle for detecting the angular position φ of the rotatable component 2 with a total of four magnetically sensitive elements 302, 304, 306, 308, whereby this measuring principle also applies to the sensor units 300 of the Fig. 2 to 6 and 9 apply.

[0047] The sensor unit 300 of the Fig. 1 has a first sensor element pair 301 arranged in the measuring plane 200, which is formed from the two magnetically sensitive elements 302, 304 arranged along a first axis 201, which runs parallel to the first direction or first axis 202. The sensor unit 300 also has a second sensor element pair 303 arranged in the measuring plane 200, which is formed from the two magnetically sensitive elements 306, 308 arranged along a second axis 203, which runs at the predetermined angle α to the first axis 301 and runs parallel to the second direction or second axis 204. The four magnetically sensitive elements 302, 304, 306, 308 are arranged on a circumference of a circle K, which extends around a center point M with a radius R. The center point M is ideally located on the rotation axis 100. In further embodiments, the center point M is closest to the rotation axis 100 (see e.g. Fig. 3 and Fig. 4).

[0048] The four magnetically sensitive elements 302, 304, 306, 308 are arranged equidistantly from one another on the circumference of the circle K, wherein the magnetically sensitive elements 302, 304 of the first sensor element pair 301 are arranged opposite one another and the magnetically sensitive elements 306, 308 of the second sensor element pair 303 are also arranged opposite one another.

[0049] The Fig. 1 that the four magnetically sensitive elements 302, 304, 306, 308 are each designed to detect the magnetic field 20 along the measuring direction 206, which runs parallel to the rotation axis 100 and orthogonal to the measuring plane 200.

[0050] In the Fig. 1, the arrows 22, 24, 26, 28 indicate the detected magnetic field components of the associated magnetically sensitive elements 302, 304, 306, 308, which are detected along the measuring direction 206. From the Fig. 1 shows that, due to the uniform spacing of the respective magnetically sensitive elements of each sensor element pair 301, 303 from the rotation axis 100, they indicate the same absolute value, with the respective directions of the magnetic field components being opposite. For example, the magnetically sensitive element 302 of the first sensor element pair 301 detects the magnetic field component 22 in the positive measuring direction 306, while the other magnetically sensitive element 304 of the first sensor element pair 301 detects the magnetic field component 24 in the negative measuring direction 206, with the magnetic field components 22, 26 being essentially equal in magnitude.

[0051] Similarly, the magnetically sensitive element 306 of the second sensor element pair 301 detects the magnetic field component 26 and the magnetically sensitive element 308 of the second sensor element pair 303 detects the magnetic field component 28. Here too, the two magnetic field components 26, 28 are opposite relative to the measuring direction 206, but are essentially equal in magnitude.

[0052] In the Fig. 1 also shows, by way of example, a magnetic interference / external field 400 that acts on all magnetically sensitive elements 302, 304, 306, 308 in the same direction and with the same magnitude. This magnetic interference / external field 400 can distort the measurement of the angular position φ of the rotatable component 2.

[0053] The negative influence of the magnetic interference / external field 400 can be compensated for by the following evaluation of the signals from the four magnetically sensitive elements 302, 304, 306, 308. For this purpose, the magnetically sensitive elements 302, 304 of the first sensor element pair 301 are connected to a first evaluation element 41 of an evaluation unit 40. The evaluation element 41 is preferably a difference former that forms the difference between the signals of the two magnetically sensitive elements 302, 304 of the first sensor element pair 301. Due to the fact that the signs of the two signals from the magnetically sensitive elements 302, 304 of the first sensor element pair are different and a difference is formed, the magnetic field components 22, 24 are added in terms of their magnitude, whereby the influence of the magnetic interference / external field 400 is compensated for.Since the magnetic interference / external field 400 acts in the same direction on the two magnetically sensitive elements 302, 304, these two influences are eliminated by subtraction. Subsequently, i.e., after compensating for the magnetic interference / external field, half of the difference is taken, thus forming the first component signal, which is subsequently processed.

[0054] In the same way, the magnetically sensitive elements 306, 308 of the second sensor element pair 303 are connected to a second evaluation element 42 of the evaluation unit 40. The second evaluation element 42 is again preferably a differential transformer and can thus compensate for the influence of the magnetic interference / external field 400 on the signals of the magnetically sensitive elements 306, 308 of the second sensor element pair 303, as already described with regard to the first evaluation element 41. The output signal of the second evaluation element 42 then represents the second component signal.

[0055] In particular, the first component signal describes the directional component of the angular position φ of the component 2 along the first direction 202, wherein the second component signal describes the directional component of the angular position φ of the component 2 along the second direction 204.

[0056] The evaluation unit 40 further comprises a third evaluation element 43 which is connected to the first evaluation element 41 and the second evaluation element 42 and is designed to generate an angle signal 44 indicating the angular position φ of the rotatable component 2 from the first component signal and the second component signal.

[0057] The connection of the evaluation unit 40 with the magnetically sensitive elements of the first and second sensor element pairs 301, 303 can be made by means of suitable connecting lines, such as bonding wires (in the Fig. 2 with solid lines). In further embodiments of the arrangement 1, the connections of the evaluation unit 40 to the magnetically sensitive elements of the first and second sensor element pairs 301, 303 can also be realized wirelessly, for example, via a suitable radio connection.

[0058] In further embodiments, additional evaluation circuits can be inserted between the magnetically sensitive elements and the evaluation unit 40 to suppress cross-influences, such as temperature dependence and mechanical stress sensitivities. For example, modulation and demodulation circuits can be arranged between the magnetically sensitive elements and the evaluation unit.

[0059] Furthermore, the magnetically sensitive elements can be constructed from multiple individual elements, such as Hall cells and / or 2- or 4-fold bridge circuits of individual magnetoresistive resistors. Furthermore, the evaluation elements can contain additional evaluation circuits. The magnetically sensitive elements can be vertical Hall cells, for example. Furthermore, at least one of the magnetically sensitive elements can be based on the magnetoresistive effect (MR). For example, a magnetically sensitive element based on the magnetoresistive effect consists of an anisotropic magnetoresistive (AMR), a giant magnetoresistive (GMR), or a tunneling magnetoresistive (TMR) element.

[0060] The Fig. 2 shows an exemplary embodiment of the sensor unit 300 according to the invention, which comprises several, but at least six, magnetic sensitive elements, which are arranged according to the Fig. 2 are arranged in several rows and columns. This results in a matrix-like arrangement of the magnetically sensitive elements. The arrangement of the magnetically sensitive elements of the sensor unit 300 along the rows and columns is preferably equidistant.

[0061] Although in the Fig. 2, the magnetically sensitive elements are arranged in a total of seven rows and seven columns, the present invention is not limited thereto. Rather, the arrangement can be along at least one row with at least six columns. It is also possible to provide fewer or more than seven rows and / or columns.

[0062] The evaluation unit 40 has, as shown in the Fig. 2, a first selection unit 52 and a second selection unit 54. The first selection unit 52 is arranged between the sensor unit 300 and the first evaluation element 41 and comprises two switches 521, 522, each of which is designed to connect a magnetically sensitive element of the first sensor pair 301 to the first evaluation element 41. Similarly, the second selection unit 54 is arranged between the sensor unit 300 and the second evaluation element 42 and comprises two switches 541, 542, each of which is designed to connect a magnetically sensitive element of the second sensor pair 303 to the second evaluation element 42.

[0063] In particular, the magnetically sensitive elements are each connected to a line 5201, 5202, 5203, 5204, 5205, 5206, 5207, to which the switches 521, 522 can connect in order to establish a connection to the first evaluation element 41. Furthermore, the magnetically sensitive elements are each connected to a line 5401, 5402, 5403, 5404, 5405, 5406, 5407, to which the switches 541, 542 can connect in order to establish a connection to the second evaluation element 42. For this purpose, for example, in the Fig. Two switches (not shown) are provided, which can establish a connection between the respective magnetically sensitive element and the associated line 5201, 5202, 5203, 5204, 5205, 5206, 5207, 5401, 5402, 5403, 5404, 5405, 5406, 5407. Each magnetically sensitive element can be controlled separately, with each sensor element being controllable only by one selection unit 52, 54 or one switch 521, 522, 541, 542. Consequently, a magnetically sensitive element cannot be controlled simultaneously by two switches 521, 522, 541, 542.

[0064] Alternatively, a separate electrical line can be provided for each magnetically sensitive element, which is connected to the first and second selection units 52, 54, respectively. In such an embodiment, the selection unit 52, 54 also has a separate switch for each magnetically sensitive element.

[0065] For example, as in the Fig. 2, the seven magnetically sensitive elements arranged in the first row are connected to line 5401 and connected via this to the first selection unit 52. Similarly, the seven magnetically sensitive elements arranged in the first column are connected to line 5201 and connected via this to the second selection unit 54.

[0066] To select the four magnetically sensitive elements of each sensor pair 301, 303 to be used for measurement, after assembly of the arrangement 1, all magnetically sensitive elements of the sensor unit 300 can be controlled separately via the switches 521, 522, 541, 542 and the additional switch (not shown) and preferably measured via the component signals. As already mentioned above, those magnetically sensitive elements of each sensor pair 301, 303 are then selected that lie on a circumference of a circle K with radius R around a center point M that is closest to the rotation axis 100. This selection is exemplified with reference to the Fig. 3 and Fig. 4 described in more detail.

[0067] This selection made by the two selection units 52, 54 is then stored in a non-volatile memory element 56 so that the magnetically sensitive elements of each sensor element pair 301, 303 already selected for the most accurate measurement are permanently available after switching off and after each restart of the arrangement 1 or sensor unit 300.

[0068] The Fig. 3 shows the sensor unit 300 of the Fig. 2 in greater detail. In the Fig. 3 shows, as an example, the intersection point of the rotation axis 100 with the measuring plane 200, whereby two possibilities for selecting the magnetically sensitive elements intended to determine the angular position of the component 2 are already indicated, namely by means of different hatchings.

[0069] From the Fig. 3 shows that the magnetically sensitive elements are arranged in a matrix-like manner in several rows and columns. In particular, the magnetically sensitive elements are arranged equidistantly from one another along a first axis 3001, which extends parallel to the first direction 202. Furthermore, the magnetically sensitive elements are arranged equidistantly from one another along at least one second axis 3002, 3003, 3004, 3005, 3006, 3007, which each extend parallel to the first axis 3001 and are spaced apart from it. Preferably, the distance between the axes 3001, 3002, 3003, 3004, 3005, 3006, 3007 is the same.

[0070] The magnetically sensitive elements are further arranged equidistantly from one another along at least one third axis 3101, 3102, 3103, 3104, 3105, 3106, 3107, each of which extends orthogonally to the first axis 3001 and thus parallel to the second direction 204. Preferably, the distance between the third axes 3101, 3102, 3103, 3104, 3105, 3106, 3107 is the same and corresponds to the distance between the axes 3001, 3002, 3003, 3004, 3005, 3006, 3007. The equidistant spacing of the magnetically sensitive elements along the plurality of axes is also the same.

[0071] The rotation axis 100 of the Fig. 3 is radially offset with respect to the center of the matrix, ie the intersection point of the two directional axes 202, 204. Consequently, it is in the Fig. 3, it is preferred to use the magnetically sensitive elements 312, 314, 316, 318, marked with diagonal hatching, for detecting the angular position φ of the component 2. In particular, these four magnetically sensitive elements 312, 314, 316, 318 are spaced equidistant from one another on a circle K with radius R around a center point M that is closest to the axis of rotation 100.

[0072] Opposite magnetically sensitive elements form a sensor element pair 301, 303. In the Fig. 3, for example, the magnetically sensitive elements 312, 314 form the first sensor element pair 301 and the magnetically sensitive elements 316, 318 form the second sensor element pair 303. Thus, one magnetically sensitive element 314, 316 of each sensor element pair 301, 302 is arranged on the first axis 3001, wherein the other magnetically sensitive element of each sensor element pair 301, 303 is arranged on one of the second axes 3002.

[0073] The selection of these four magnetically sensitive elements 312, 314, 316, 318 is again carried out by the Fig. 2. Furthermore, this selection is only made after the sensor unit 300 has been assembled with the magnet 10 and the component 2, since the assembly is subject to geometric tolerances and only after the assembly are those four magnetically sensitive elements selected with which the most accurate measurement result and consequently the smallest measurement error can be expected.

[0074] As an alternative to the diagonally hatched magnetically sensitive elements 312, 314, 316, 318, the four vertically hatched magnetically sensitive elements 322, 324, 326, 328 of the Fig. 3 can be used. This may be preferred because they are arranged equidistant from one another on a circle K' with radius R' around the center M, wherein the radius R' is larger than the radius R. By selecting a larger radius, the measurement accuracy can be at least partially increased.

[0075] In the Fig. 4 is the sensor unit 300 of the Fig. 3, wherein the rotation axis 100 is again radially offset relative to the center of the measuring plane 200. According to the Fig. 4, it is advantageous to use the magnetically sensitive elements marked obliquely hatched or alternatively vertically hatched to determine the angular position φ of the component 2.

[0076] In particular, the center point M of the circle K with radius R, on which the magnetically sensitive elements 312, 314, 316, 318 are arranged equidistant from one another, is again closest to the axis of rotation 100, which is why precisely the magnetically sensitive elements marked with diagonal hatching or vertical hatching were selected, with which the angular position φ of the component 2 can be detected as accurately as possible.

[0077] The magnetically sensitive elements of each sensor element pair 301, 303 are arranged opposite one another on the circle, with the magnetically sensitive elements 312, 314 of the first sensor pair 301 being arranged on the second axis 3002 and the magnetically sensitive elements 316, 318 of the second sensor pair 303 being arranged on the third axis 3101. The third axis 3101 is a perpendicular bisector to the magnetically sensitive elements 312, 314 of the first sensor element pair 301, and the third axis 3101 is a perpendicular bisector to the magnetically sensitive elements 316, 318 of the second sensor element pair 303.

[0078] Alternatively, the magnetically sensitive elements 322, 324, 326, 328 can be used to determine the angular position, which lie on a circle K' with radius R' around the center M, where the radius R' is larger than the radius R. This in turn can at least partially increase the measurement accuracy.

[0079] In the Fig. 4, the rotation axis 100 is closest to a magnetically sensitive element 311 that is centrally arranged relative to the selected magnetically sensitive elements 312, 314, 316, 318. Due to the equidistant arrangement of all magnetically sensitive elements, the center point M of the circles K, K' lies on this central magnetically sensitive element 311. The centrally arranged magnetically sensitive element 311 can be determined, for example, by recording the signals from all magnetically sensitive elements and defining the one that indicates the smallest value as the central magnetically sensitive element 311. This magnetically sensitive element 311 is then closest to the rotation axis 100.

[0080] Depending on the position of the rotation axis 100, the four magnetically sensitive elements 312, 314, 316, 318 can be arranged according to the Fig. 3 or Fig. 4. In both alternatives, the center point M of the circles K with radius R, on which the four magnetically sensitive elements 312, 314, 316, 318 are arranged equidistant from one another, is closest to the rotation axis 100, which is why precisely these four magnetically sensitive elements 312, 314, 316, 318 are each used to determine the angular position φ of component 2. Alternatively, the magnetically sensitive elements 322, 324, 326, 328 could each be used.

[0081] The Fig. Figure 5 shows another possible matrix-like arrangement of the magnetically sensitive elements of the sensor unit 300, in which the rows and columns are offset from one another. Here, too, depending on the position of the rotation axis 100, two pairs of sensor elements 301, 303 can be determined, whose magnetically sensitive elements are arranged equidistant from one another on a circle K with radius R around a center point M that is closest to the rotation axis 100.

[0082] Due to the matrix-like arrangements of the magnetically sensitive elements of the sensor units 300 of the Fig. 3 to 5, the maximum possible offset of the rotation axis 100 with respect to the respective center points M of the circles K, K', on which the four magnetically sensitive elements 312, 314, 316, 318 selected for determining the angle signal 44 are arranged equidistantly from one another, can be limited to at least half the equidistant distance between adjacent magnetically sensitive elements. Depending on the resolution of the matrix, the measurement error introduced by the offset of the rotation axis 100 can thus be at least partially reduced.

[0083] It goes without saying that the two-dimensional coordinate system spanned by the first and second axes 202, 204 can be rotated in the measuring plane. Thus, magnetically sensitive elements of sensor element pairs could also be used, which are arranged on diagonal axes in the Fig. 3 to 5 are arranged.

[0084] The Fig. Fig. 6 shows a further sensor unit 300 according to the invention, in which several sensor groups 330 to 338 are provided (each marked by dashed frames), each having four magnetically sensitive elements of the first and second sensor element pairs 301, 303. In particular, the magnetically sensitive elements of the sensor unit 300 of the Fig. 6 are only partially equidistant from each other. In the Fig. 6, the sensor grouping 330 is arranged centrally and the sensor groupings 331 to 338 are arranged around the central sensor grouping 330.

[0085] The magnetically sensitive elements of the sensor groups 330 to 338 are preferably arranged such that each magnetically sensitive element of a respective sensor group 330 to 338 is arranged on at least one axis of an adjacent sensor group 330 to 338. For example, the magnetically sensitive elements 3302, 3332 of the sensor groups 330, 333 are each arranged on a common axis 3002. Furthermore, the magnetically sensitive elements 3346, 3352 of the sensor groups 334, 335 are arranged on a common axis 3008. In addition, the magnetically sensitive elements 3302, 3352 of the sensor groups 330, 335 are arranged on a common axis 3102 and the magnetically sensitive elements 3332, 3346 of the sensor groups 333, 334 are arranged on a common axis 3108.In particular, the magnetically sensitive elements 3304, 3332, 3346, 3354 of the different sensor groups 330, 333, 334, 335 are arranged on a common circle (not shown) around a center point M which is closest to the axis of rotation 100.

[0086] According to the Fig. 6, the magnetically sensitive elements 3302, 3346 thus form a first sensor element pair and the magnetically sensitive elements 3332, 3352 form a second sensor element pair.

[0087] In this way, the design of the Fig. 6, several axes can be found, on each of which magnetically sensitive elements of different sensor groups 330 to 338 are arranged. In particular, these common axes can be arranged similarly to the embodiments of Fig. 3 to 5, are defined as first, second and third axes on which the magnetically sensitive elements of the first and second sensor element pairs 301, 303 are arranged.

[0088] In the Fig. 6 also shows two exemplary axes of rotation, namely a first axis of rotation 100A and a second axis of rotation 100B, which are each radially offset differently from the center of the central sensor grouping 330.

[0089] In the case of the first rotary axis 100A, the four in the Fig. 6 magnetically sensitive elements of the sensor grouping 336, marked diagonally with hatching, are selected to determine the angle signal 44. This is because these four magnetically sensitive elements of this sensor grouping 336 lie on a circle K (not shown) around a center point M, which is obviously closest to the first axis of rotation 100A.

[0090] In the case of the second rotation axis 100B, it is preferable to select the four magnetically sensitive elements 3302, 3332, 3346, 3352 of the sensor groupings 330, 333, 334, 335 marked with vertical hatching, since the center point M' of a circle on which these four magnetically sensitive elements 3302, 3332, 3346, 3352 are arranged equidistantly is closest to the second rotation axis 100B.

[0091] The two described cases for the rotation axes 100A, 100B illustrate that, despite a non-equidistant arrangement of the magnetically sensitive elements, there are several possibilities for the sensor unit 300 to determine the angular position of the component with the greatest measurement accuracy. Furthermore, in the design of the sensor unit 300 according to the Fig. 6, it is possible to select pairs of sensor elements whose magnetically sensitive elements are arranged on diagonal axes which run at an angle of approximately 45° to the directional axes 202, 204.

[0092] With reference to the Fig. 7 to 9, it will now be explained how a sensor arrangement 300 according to the invention for detecting the path position of a moving object with a rod-shaped magnet 10 (in the Fig. 7 to 9 marked with dashed lines) along a linear movement path (marked with arrow 6) of a movable component 2 (not explicitly shown). The sensor units 300 of the Fig. 7 to 9 therefore represent electronic rulers with which, for example, displacements of component 2 along a linear or non-linear movement path can be quantitatively recorded.

[0093] The sensor unit 300 of the Fig. 7 and Fig. 8 has at least six magnetically sensitive elements 311, 312, 313, 314, 315, 316, which are arranged equidistant from one another along a first axis 3002. First, the signals from all magnetically sensitive elements 311, 312, 313, 314, 315, 316 are recorded, and those two magnetically sensitive elements that output the largest values ​​are selected as the sensor element pair. Fig. 7, these are, for example, the magnetically sensitive elements 311, 312 (see diagonally hatched magnetically sensitive elements in the Fig. 7 and Fig. 8) .

[0094] The detection of the path position or the output of the path signal 44 is then essentially analogous to the process already described with regard to the Fig. 1 and Fig. 2. More precisely, the differences between the signals of the two magnetically sensitive elements 311, 312 are again formed. For this purpose, the evaluation unit 40 can again have corresponding evaluation elements as difference images (analog or digital). In this one-dimensional evaluation, the first component signal can already correspond to the displacement signal 44.

[0095] The Fig. 8 shows the sensor unit 300 of the Fig. 7, wherein in this embodiment the magnetically sensitive elements 314, 316 are selected as the first sensor element pair 301, with which the path position 44 of the component 2 is determined. Fig. 8 is the magnet 10 compared to the Fig. 7 is shifted to the right, which is why the magnetically sensitive elements 314, 316 can be selected in this constellation.

[0096] In the Fig. 8, the magnetically sensitive elements 311, 313 marked with vertical hatching can additionally be selected as the second sensor element pair 303 and evaluated to form a redundant displacement signal 44, which can also be used to compensate for the influence of any magnetic interference / external fields 400. For this purpose, the distances between the magnetically sensitive elements of the two sensor pairs 301, 303 must be selected such that they are equal. This means that the distance between the magnetically sensitive elements 314, 316 of the first sensor element pair 301 is equal to the distance between the magnetically sensitive elements 311, 313 of the second sensor element pair 303.

[0097] The Fig. Figure 9 shows a further sensor unit 300 according to the invention for detecting the travel position 44 of the component 2. The sensor unit 300 comprises at least six magnetically sensitive elements arranged in two rows. In particular, in the design of the Fig. 9 four magnetically sensitive elements 311, 312, 313, 314 are arranged equidistantly from one another along a first axis 3002, and four magnetically sensitive elements 321, 322, 323, 324 are arranged equidistantly from one another along a second axis 3004 running parallel to the first axis 3002. In addition, the magnetically sensitive elements 311, 312, 313, 314, 321, 322, 323, 324 are arranged along third axes 3102, 3104, 3106, 3108, which run parallel to one another and orthogonal to the first and second axes 3002, 3004. Consequently, Fig. 9 again shows a matrix-like arrangement of the magnetically sensitive elements of the sensor unit 300 with two rows and four columns.

[0098] Depending on the relative position of the magnet 10 (and thus also of the component 2), the relevant two magnetically sensitive elements can be selected, based on whose signals the path position of the component 2 can be determined. In the example of the Fig. 9, for example, the two magnetically sensitive elements 311, 312 are selected because the substantially rod-shaped magnet 10 is closest to this second row and to this pair of sensor elements 301.

[0099] The sensor unit 300 of the Fig. 9 can, however, alternatively or additionally be used in such a way that the angular position φ of a rotating element about the rotation axis 100 (see black marked point in the Fig. 9) rotatable component 2. For this purpose, for example, the Fig. 9 magnetically sensitive elements 313, 314, 323, 324 marked diagonally hatched. The selection and evaluation of these relevant magnetically sensitive elements 313, 314, 323, 324 is carried out in a similar manner as already described with regard to the Fig. 3 to 6.

[0100] The sensor unit 300 according to the invention can also be designed to detect an absolute position of the magnet 10 and / or component 2. If the component 2 and / or the magnet 10 moves in a plane of movement arranged parallel to the measuring plane, for example, with the sensor unit 300 according to Fig. 3 the absolute position of the component 2 and / or magnet 10 can be estimated by being closest to the magnetically sensitive element(s) which output(s) the largest value(s).

[0101] With the sensor unit according to the invention disclosed herein, it is possible to provide several magnetically sensitive elements and, only after arranging the sensor unit relative to a magnet that moves with a component whose angular and / or displacement position is to be detected by the sensor unit, to select those magnetically sensitive elements with which maximum measurement accuracy can be achieved, free from the influence of any external magnetic / interference fields. Thus, the selection of the magnetically sensitive elements relevant for the measurement is flexible, so that while the sensor unit according to the invention can be identical for a variety of applications, different magnetically sensitive elements can be used to detect the respective angular and / or displacement position of the component.

[0102] It is expressly stated again that all the Fig.The features shown and described in Figures 1 to 9 are disclosed independently of one another and can therefore be combined with one another as desired.

Claims

[1] Sensor unit (300) for detecting the position (φ) of a component (2), the sensor unit (300) comprising: - at least six magnetically sensitive elements arranged in a measuring plane (200), each of which is designed to detect a magnetic field (20) exclusively along a measuring direction (206) extending orthogonally to the measuring plane (200), and - an evaluation unit (40) which is connected to the magnetically sensitive elements of the sensor unit (300) and is designed to determine a position signal (44) corresponding to the position (φ) of the component (2) based on the signals from a first sensor element pair (301) of magnetically sensitive elements and / or based on the signals from a second sensor element pair (303) of magnetically sensitive elements, wherein the evaluation unit (40) comprises: - a first selection unit (52) which is designed to establish a connection to the selectable magnetically sensitive elements of the first sensor element pair (301), and - a second selection unit (54) which is designed to establish a connection to the selectable magnetically sensitive elements of the second sensor element pair (303). [2] Sensor unit (300) according to claim 1, wherein the signals of all magnetically sensitive elements are detected and those magnetically sensitive elements are defined as belonging to the first sensor element pair (301) of magnetically sensitive elements which each output the largest value in terms of magnitude, and / or those magnetically sensitive elements are defined as belonging to the second sensor element pair (303) of magnetically sensitive elements which each output the largest value in terms of magnitude. [3] Sensor unit (300) according to one of the preceding claims, wherein the sensor unit (300) is designed to determine an angle signal (44) corresponding to the angular position (φ) of the component (2) rotating about an axis of rotation (100) based on the signals from those four magnetically sensitive elements of the first and second sensor element pair (301, 303) which are each arranged equidistant from one another on a circumference of a circle (K) around a center point (M, M') which is closest to the axis of rotation (100) in the measuring plane (200). [4] Sensor unit (300) according to claim 3, wherein the center point (M, M') of the circle (K) is determined by being closest to the magnetically sensitive element which outputs the smallest value in terms of magnitude. [5] Sensor unit (300) according to one of the preceding claims, wherein the magnetically sensitive elements are arranged equidistantly at least partially along a first axis (3001) running in the measuring plane (200) and / or at least partially along at least one second axis (3002, 3003, 3004, 3005, 3006, 3007) running in the measuring plane (200) parallel to the first axis (3001). [6] Sensor unit (300) according to claim 5, wherein the magnetically sensitive elements arranged on the first axis (3001) and the magnetically sensitive elements arranged on the at least one second axis (3002, 3003, 3004, 3005, 3006, 3007) are each further arranged on at least one third axis (3101, 3102, 3103, 3104, 3105, 3106, 3107) extending in the measuring plane (200) at a predetermined angle (α) to the first axis (3001). [7] Sensor unit (300) according to claim 6, wherein one magnetically sensitive element of the first sensor element pair (301) is arranged on the first axis (3001) and the other magnetically sensitive element of the first sensor element pair (301) is arranged on the at least one second axis (3002, 3003, 3004, 3005, 3006, 3007) and / or one magnetically sensitive element of the second sensor element pair (303) is arranged on the first axis (3001) and the other magnetically sensitive element of the second sensor element pair (303) is arranged on the second axis (3002, 3003, 3004, 3005, 3006, 3007). [8] Sensor unit (300) according to one of claims 6 and 7, wherein the magnetically sensitive elements of the first sensor element pair (301) are arranged on the first axis (3001) and the magnetically sensitive elements of the second sensor element pair (303) are arranged on the at least one third axis (3101, 3102, 3103, 3104, 3105, 3106, 3107), wherein the first axis (3001) runs as a perpendicular bisector to the magnetically sensitive elements of the second sensor element pair (303) and the third axis (3101, 3102, 3103, 3104, 3105, 3106, 3107) runs as a perpendicular bisector to the magnetically sensitive elements of the first sensor element pair (301). [9] Sensor unit (300) according to one of the preceding claims, wherein the evaluation unit (40) further comprises a non-volatile memory device (56) which is designed to non-volatilely store the selection of the selected magnetically sensitive elements of the first and / or second sensor element pair (301, 303) made by the first selection unit (52) and / or second selection unit (54). [10] Arrangement (1) for detecting the position (φ) of a component (2), the arrangement (1) comprising: - a magnet (10) designed to generate a magnetic field (20), and - a sensor unit (300) according to one of the preceding claims, wherein the sensor unit (300) is spaced from the magnet (10) and is designed to detect the magnetic field (20) along a measuring direction (206) extending orthogonally to the measuring plane (200) and to output therefrom a position signal (44) corresponding to the position (φ) of the component (2). [11] Arrangement (1) according to claim 10, wherein the magnet (10) or the sensor unit (300) are arranged together with the component (2) to be rotatable about an axis of rotation (100) and the sensor unit (300) is designed to detect the magnetic field (20) along the measuring direction (206) and to output therefrom an angle signal (44) corresponding to an angular position (φ) of the component (2). [12] Arrangement (1) according to claim 10, wherein the magnet (10) or the sensor unit (300) are arranged to be movable together with the component (2) along a movement path and the sensor unit (300) is designed to detect the magnetic field (20) along the measuring direction (206) and to output therefrom an angle signal (44) corresponding to an angular position (φ) of the component (2).

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