DE102019213389A1 - Sensor arrangement for detecting an angle of rotation of a flux element - Google Patents

Abstract

A sensor arrangement (2) for detecting an angle of rotation (D) of a flux element (12) which can be rotated along a circular path (14) about an axis of rotation (10) contains at least one coil group (4a, b) each with at least two coils (6a) -d) in a surface (16) concentrically surrounding the axis of rotation (10) parallel to and along the circular path (14), a respective coil group (4a, b) being limited to a respective coil angle (S1,2), the Add the coil angles (S1,2) of all coil groups (4a, b) to a total angle (G) of less than 360 °, and at least one empty area (8a, b) which extends over a respective empty angle (E1,2), and the flux element (12) parallel to the surface (16), which has an angular extent (W) that is greater than the largest coil angle (S1,2), and an evaluation device (18) for determining the current inductance (L1-4) of the Coils (6a-d) and the current angle of rotation (D) based on the inductances (L1-4).

Description

The invention relates to a sensor arrangement for detecting an angle of rotation of a flux element that is rotatable about an axis of rotation along a circular path.

A rotor position sensor for drive motors, for example of electric vehicles, which is based on the modulation of eddy currents and the use of coil pairs, is off "Development of Eddy-Current Rotor Position Sensor, Markus Simon, Business Unit 8, SUMIDA Components & Modules GmbH, Presented at EVTeCand APE Japan on May 23, 2014, JSAE Paper No. 20144103 ‟ ("140523_EVTeC_speech.pdf", download from "https://www.sumida.com/news/index.php?categoryld=3&newsld=116" on June 19, 2019).

The object of the present invention is to propose improvements in relation to a rotation angle detection.

The object is achieved by a sensor arrangement according to patent claim 1. Preferred or advantageous embodiments of the invention and other categories of the invention emerge from the further claims, the following description and the attached figures.

The sensor arrangement is used to detect an angle of rotation of a flux element. The flux element can be rotated about an axis of rotation along a circular path. The sensor arrangement contains at least one, in particular exactly one, in a preferred embodiment at least two, coil group (s) interacting with the flux element. Each of the coil groups contains at least two coils. The interaction comprises a relative rotation between the coil and the flux element through different angles of rotation. Depending on the angle of rotation, a magnetic field generated by the coil generates eddy currents of varying strength in the flux element, so that the inductances of the coil change in each case. These inductances can be measured and thus conclusions can be drawn about the relative position between coil and flux element and thus about the angle of rotation. The coils are in particular flat coils, the flux element is in particular plate-shaped, for example a copper plate or a copper activator. In particular, the coils and the flux element are arranged flat parallel to one another or rotatable with respect to one another with the interposition of an in particular narrow air gap.

The coil groups extend in a surface concentrically surrounding the axis of rotation. The orientation of the surface to the axis of rotation can be selected differently, see below. The area runs parallel to the circular path and along the circular path. A respective coil group is limited along the circular path to a respective coil angle, i.e. a part of the circumference. The coil group is therefore limited to a certain angular section in the circumferential direction of the axis of rotation, e.g. a maximum or exactly 180 ° (for a coil group) or a maximum or exactly to a quadrant of 90 ° (for at least two coil groups).

The coil angles of all coil groups add up to a total angle of less than 360 °. So not the entire circumference around the axis of rotation is occupied by groups of coils. Along the circular path there is therefore at least one empty area (in the embodiment of at least two coil groups: between two coil groups each) in which there is no coil group or coil. The respective empty area extends over a respective empty angle. The sum of all empty angles and the total angle results in the entire circumference of 360 ° around the axis of rotation.

The sensor arrangement also contains the flux element, which extends parallel with the interposition of a spacing gap to the surface and thus to the coils in order to act differently depending on the angle of rotation on the inductances of the coils. The flux element has an angular extent along the circular path that is greater than the largest coil angle.

The sensor arrangement contains an evaluation device which is set up to determine for each of the coils their current inductance (i.e. depending on the relative position between flux element and coil or angle of rotation) and to determine a current angle of rotation of the flux element on the basis of at least two, especially all, to determine determined inductances.

All angles are to be considered as angles with respect to the axis of rotation, i.e. in the circumferential direction of the axis of rotation, i.e. along the circular path.

The invention is based on the knowledge that inductive rotor angular-position measurement sensors (IRPS) require a large circuit board area when trapezoidal planar coils with a rotational shape have to be printed on an entire ring-shaped circuit board. In addition, such large trapezoidal coils produce the change in inductance signals (which are complex functions of the angular position of the copper activator or target). Therefore, the generated functions of the inductances versus the angle of rotation are not easy to achieve with inexpensive signal shaping hardware and microcontroller / signal processor to process. In short, complex signal processing algorithms have to be developed and their implementation requires expensive microcontrollers / signal processors (DSP, digital signal processors).

According to the invention, this results in a reduction in the costs for circuit boards or coils and a simpler determination of the angle of rotation through a simpler evaluation of the sensor signal or the determined inductances.

The invention can be implemented for both radial and axial versions of sensor arrangements or sensors, see below. The invention can be used in particular for detecting the rotor position of an electric machine or an electric motor, and in particular in e-mobility projects.

In a preferred embodiment - as explained above - at least two coil groups are present, and along the circular path there is at least one empty area between every two coil groups. This results in distributed coil structures which, in particular, can be designed to be point-symmetrical / rotationally symmetrical.

In a preferred embodiment, the same number of coil groups and empty areas are arranged alternately along the circular path. This enables a simple and, from two coil groups, a particularly symmetrical and simple structure, in which coil groups with empty areas always alternate in the circumferential direction around the axis of rotation. This also results in advantages with regard to a flux element which protrudes beyond the coil groups, see below.

In a preferred variant of the embodiment with at least two coil groups, at least two of the coil angles are of the same size and / or at least two of the empty angles are of the same size. In particular, all coil angles are the same size and / or all empty angles are the same size. Alternatively or additionally, at least one, in particular all, coil angles and one, in particular all, empty angles are the same size. This leads to particularly simple arrangements.

In a preferred variant of the embodiment with at least two coil groups, there are exactly two coil groups and exactly two empty areas. In total, there are thus a minimum of four, in particular exactly four, coils. This results in a particularly simple embodiment. In particular, a two-quadrant arrangement can thus take place, see below.

In a preferred embodiment - in particular the variant with exactly one coil group - the total angle is 180 ° and / or the angular extent is 360 ° and / or at least one of the coil angles is 180 ° and / or at least one of the empty angles is 180 °. For a total angle of 180 °, only half of the circumference around the axis of rotation results as the area required for coils or circuit boards on which coils are arranged. An angular expansion of 360 ° for the flux element is particularly suitable in a 180 ° arrangement of precisely one coil group.

In a preferred variant of the embodiment with at least two coil groups, the total angle is 180 ° and / or the angular extent is 180 ° and / or at least one of the coil angles is 90 ° and / or at least one of the empty angles is 90 °. For a total angle of 180 °, only half of the circumference around the axis of rotation results as the area required for coils or circuit boards on which coils are arranged. An angular expansion of 180 ° for the flow element is particularly suitable in a two-quadrant arrangement, see below. Corresponding 90 ° angles are also suitable for this two-quadrant arrangement, see below.

In a preferred embodiment, the flow element is designed to be contiguous along the circular path. This results in a particularly simple flow element. Alternatively, the flow element is divided into at least two sections. Here again the alternatives arise that at least two of the sections adjoin one another and / or are spaced apart from one another. The flow element can thus have different sections or parts that do not all have to be connected; one or more gaps may exist between adjacent sections. Advantages for correspondingly designed flux elements arise depending on the specific arrangement and division of the coil groups.

In a preferred embodiment, the angular extent is at least as large as the largest sum of a coil angle and an adjacent empty angle with the given division for a specific sensor arrangement. This ensures for all angles of rotation that the flux element can always completely cover every pair of adjacent coil groups and empty angles. This leads to a particularly easy evaluation of the angle of rotation from the inductances.

In a preferred variant of the embodiment with at least two coil groups, there is at least one coil type for identical coils and at least two coil groups each contain one of the same coils. These coils are then arranged rotationally symmetrical to the axis of rotation. This is to be understood as meaning that these emerge from one another or are congruent by rotating them by the difference angle of the coil groups. Thus, within the coil type, the coils are mirrored or rotated, in particular by an angle of 360 ° divided by the number of coil groups. In particular, four coils are provided in two coil types in two coil groups of two coils each. A particularly simple and homogeneous evaluation of the inductances can take place by means of correspondingly identical coils.

In a preferred variant of this embodiment, a respective section of the flux element is assigned to at least one type of coil. In particular, exactly two different coil types are provided, and thus exactly two sections, that is to say one per coil type. This leads to a further homogenization of the evaluation of the inductances.

In a preferred variant of this embodiment, at least one of the sections is congruent with the assigned coil type. In particular, for a specific angle of rotation the section covers exactly a respective coil of the coil type, that is to say forms a parallel image of the corresponding coil transversely to its direction of extension. Thus, with maximum effect on the inductances of the coil, the dimensions or the transverse extent of the section parallel to the coil are kept as small as possible.

In a preferred embodiment, in at least one of the coil groups, at least two of the coils lie next to one another in the area perpendicular to the circular path. This applies in particular in the radial direction or axial direction of the axis of rotation. This applies in particular to all coil groups and all coils. In particular, different sections that are assigned to corresponding coils or coil types can be arranged particularly favorably in the flux element.

In a preferred embodiment, at least one of the coils has a shape that tapers along the circular path. The tapering relates to a certain direction of rotation with respect to the axis of rotation, in the opposite direction the coil is then designed to widen. In particular, tapering or widening for different coils of a coil group are designed in opposite directions, in particular in the case of two coils. In this way, particularly favorable inductance curves can be generated over the angle of rotation of the flux element.

In a preferred embodiment, at least one of the coil groups has the shape of a circular ring segment or a circumferential section of a circular cylinder jacket. This results in geometrically particularly simple embodiments for the coil groups. In this way, particularly simple geometric shapes are also possible for the flow element. In particular, this embodiment can be combined with the arrangement of the coils “next to one another”.

In a preferred embodiment, the surface has the shape of a disk transverse to the axis of rotation. An axial arrangement can thus be created. Alternatively, the surface has the shape of the jacket of a straight circular cylinder with respect to the axis of rotation. A radial arrangement can thus be created. Alternatively, the surface has the shape of a jacket of a right circular truncated cone with respect to the axis of rotation. This results in a conical "mixed form" of the arrangement between circular disk and cylinder form. In this way, a suitable geometry of the sensor arrangement can always be selected for many geometrical requirements.

The invention is based on the following findings, observations and considerations and also has the following embodiments. The embodiments are sometimes also referred to as “the invention” in a simplified manner. The embodiments can here also contain parts or combinations of the above-mentioned embodiments or correspond to them and / or optionally also include embodiments not mentioned so far.

According to the invention, planar trapezoidal coils (in the form of rotation) are in particular in a first semicircular circumference (for a single coil group) or in a first and third quadrant (for at least two or exactly two coil groups) of a circular disk (circuit board, based on the circumference around the axis of rotation) , PCB, printed circuit board). Therefore, half the board area is required compared to a sensor in which the circuit board completely surrounds the axis of rotation. This reduces both the size of the sensors and the circuit board costs. A very special form of the flux element is proposed, in particular a copper (Cu) activator element, namely similar, in particular corresponding or identical to the coil contours. The rotary movement of this flux element (Cu activator element) creates a simple "scissors / X-shaped" course of the inductance L (nH) of the coils over the angle of rotation or a theta (°) rotation position. Due to the simple nature of the inductance curve, an angular position detection algorithm (algorithm for determining the angle of rotation) and its implementation processor (microcontroller) can be used in the form of a low-cost solution.

• 1 zwei Spulengruppen und zwei Leerbereiche einer Sensoranordnung,
• 2 ein Flusselement der Sensoranordnung aus 1,
• 3 die zusammengebaute Sensoranordnung aus 1,2 bei Drehwinkeln des Flusselements von a) 0°, b) 90°, c) 180° und d) 270°.
• 4 den Verlauf der Induktivitäten der Spulen der Sensoranordnung aus den 1-3 über dem Drehwinkel,
• 5 a) Spulengruppen und Leerbereiche und b) ein Flusselement einer alternativen Sensoranordnung,
• 6 Simulationsergebnisse für ein im Uhrzeigersinn rotierendes Flusselement,
• 7 eine Zustandstabelle für eine Flusselement-Rotation im Uhrzeigersinn,
• 8 eine alternative Sensoranordnung mit einer einzigen Spulengruppe.

Further features, effects and advantages of the invention emerge from the following description of a preferred exemplary embodiment of the invention and the attached figures. They show, in each case in a schematic principle sketch:

• 1 two coil groups and two empty areas of a sensor arrangement,
• 2 a flow element of the sensor arrangement 1 ,
• 3rd the assembled sensor assembly 1 , 2 at angles of rotation of the flux element of a) 0 °, b) 90 °, c) 180 ° and d) 270 °.
• 4th the course of the inductances of the coils of the sensor arrangement from the 1-3 over the angle of rotation,
• 5 a) Coil groups and empty areas and b) a flux element of an alternative sensor arrangement,
• 6th Simulation results for a clockwise rotating flux element,
• 7th a state table for a clockwise flow element rotation,
• 8th an alternative sensor arrangement with a single coil group.

The 1 and 2 together show a disassembled sensor assembly 2 . 1 shows a first part of the sensor arrangement 2 , namely two groups of coils 4a , b with two coils each 6a-d as well as two empty areas 8a , b . Each of the coils 6a-d has a respective inductance L1-L4 on. The sensor arrangement has an axis of rotation 10 on that in the 1-3 each runs perpendicular to the plane of the drawing.

2 shows a second and thus remaining part of the sensor arrangement 2 , namely a flow element 12th , which is around the axis of rotation 10 along a circular path 14th is rotatable. The circular path 14th runs in 2 in the plane of the paper and is only partially shown. The sensor arrangement 2 is used to detect an angle of rotation D. of the flow element 12th around the axis of rotation 10 relative to the in 1 shown part of the sensor arrangement 2 .

The flow element 12th points along the circular path 14th an angular extent W. from 180 ° to.

In the assembled state of the sensor arrangement 2 (please refer 3rd ) is the flow element 12th only by a spacing gap symbolically indicated here a , here an air gap, separated above (ie facing the viewer in the figure) of the arrangement 1 . Therefore there is an interaction between the flux element 12th and coils 6a-d in that the inductors L1-4 of the coils 6a-d depending on the angle of rotation D. of the flow element 12th vary.

The coil groups 4a , b extend in one of the axis of rotation 10 concentrically surrounding area 16 , in the 1 corresponds to the plane of the paper and transversely to the axis of rotation 10 runs. The area 16 runs parallel to the circular path 14th and also along the circular path 14th . The flow element 12th therefore extends parallel with the interposition of the spacing gap a to the surface 16 .

Along the circular path 14th , that is, in the circumferential direction with respect to the axis of rotation 10 are both the coil group 4a as well as the coil group 4b each on a bobbin angle S1 and S2 limited by 90 °. Both spool angles S1 and S2 add up to a total angle G of 180 °.

The two empty areas 8a , b are located between the two coil groups 4a , b and extend over a respective empty angle E1 and E2 of 90 ° each. Overall, this results in a two-quadrant arrangement with coils 6a-d in just two quadrants Q1 , 3rd .

The angular extent W. of 180 ° is at least (or here exactly the same) as large as the largest possible sum of a coil angle (here both S1, 2 = 90 °) and an empty angle (here also both E1, 2 = 90 °) with the given sensor arrangement 2 . The largest sum is thus also 180 °.

Is only symbolic in 1 another evaluation device 18th the sensor arrangement 2 shown. This is set up - here by programming a digital signal processor (not shown) - for each of the coils 6a-d their current inductances at a certain point in time L1-4 or to determine the corresponding inductance value and a current angle of rotation D. of the flow element 12th based on the four determined inductances L1-L4 to determine. The determination takes place on the basis of essentially simple geometric or field-theoretical considerations that are customary in the art, in accordance with angle sensors that are known in principle and that work in the same way, and will not be explained in more detail here.

The 1 and 2 show a small and compact inductive rotor angular position measurement sensor (Small and Compact Inductive Rotor Angular Position Measurement Sensor: SCIRAMS). In particular, they show an axial type of IRAMS, ie an axial IRPS (Inductive Rotor Position Sensor).

1 shows two small circuit boards 20a , b (PCB) in the form of a quarter of a disc (quarter-circular ring segments), which are in a first Quadrant Q1 (Angle of rotation 0 ° to 90 °) and third quadrant Q3 (Angle of rotation 180 ° to 270 °) are mounted, each on a non-metallic circular disc 22nd (Circular ring). In the circuit board 20a , so in the Q1-PCB, the two trapezoidal coils are of the planar type, namely coil 6a or. L1 and coil 6b or. L2 printed in rotation form (i.e. the axis of rotation 10 along the circular path 14th surrounding). Similarly are in the circuit board 20b , i.e. in the Q3-PCB, two flat trapezoidal coils, namely coil 6c or. L3 and coil 6d or L4 arranged, which are also in rotation form.

It should be noted that the radially outer coils 6a , c (Q1-PCB and Q3-PCB) are odd numbered ( L1 and L3 ) and the radially inner coils 6b , d (Q1-PCB and Q3-PCB) are even numbered ( L2 and L4 ). In contrast, the Q2 and Q4 quadrants have the circular disk 22nd no PCBs and therefore do not contain any planar trapezoidal coils. In addition, the two are odd-numbered coils 6a ( L1 ) and 6c ( L3 ) of the same coil type 24a (Geometry / shape / contour, track width, winding spacing and number of windings, etc.), and the two even-numbered coils are also in the same way 6b ( L2 ) and 6d ( L4 ) of the same coil type 24b (geometry / shape / contour, track width, winding spacing and number of windings, etc.). 1 shows the circular disk 22nd who have favourited PCBs with Trapezoidal Planar Coils 6a-d wearing.

2 shows a thin / laminar CU activator in the form of the flow element 12th that is just above the trapezoidal coils 6a-d slides / rotates while leaving a fixed gap (spacing gap a ) maintains.

The circular disc points in the center 22nd a circular recess or hole 26th for the assembly (enforcement) of a rotor shaft, not shown.

2 shows a thin and laminar metallic (made of Cu) semicircular plate in the form of the flux element 12th that act as an activator / target for the inductive sensor or the sensor arrangement 2 acts. The flow element 12th has two sections A1 and A2 which are detailed here in a coherent manner. The rotating flux element 12th has the purpose of the inductors L1-4 of the respective stationary coils 6a-d (the one under the A1 or A2 part or section of the flow element 12th is) to change / decrease under the influence of eddy currents, which are in the metallic flux element 12th form. The contour of the A2 section of the flow element 12th is identical to the contour of the even-numbered ( L2 and L4 ) inner trapezoidal planar coils 6b , d (Coil type 24b). Similarly, the contour of the A1 section of the flow element is 12th identical to the contour of the odd ( L1 and L3 ) outer trapezoidal planar coils 6a , c (Coil type 24a ). The respective sections A1 and A2 and the associated coils 6a , c and 6b , d are therefore each congruent.

The arc lengths B1 , 2 from A1 - section and A2- section of the flow element 12th are dimensioned in such a way that the A1 section is e.g. one quadrant of the disc, e.g. on the left side of the circular disc 22nd , completely covers and the A2 section another quadrant, e.g. on the right side of the circular disc 22nd , completely covers. Therefore it covers the entire length of the arc (angular extent W. ) of the flow element 12th (A1 and A2 sections together) two neighboring quadrants or a semicircle of the circular disc 22nd . The connecting line (or center in the circumferential direction) of the A1 and A2 sections of the flow element 12th serves as a pointer for the angular position measurement (see 3rd ).

3rd shows the fully assembled sensor arrangement 2 with components 1 and 2 .

In 3a is the thin / laminar Cu activator in the form of the flow element 12th positioned so that it has the L1 coil 6a completely covers. This position is called the 0 ° position of the angle of rotation D. considered as the line connecting the sections A1 and A2 of the flow element 12th to the 0 ° position of the angle of rotation D. is aligned. The flow element 12th is now located or rotating above the coils 6a-d and keeps the fixed gap a upright.

The section A1 is completely in the quadrant Q1 and therefore covers the coil 6a ( L1 ). The section A2 is located in quadrant Q4 above the circular disk 22nd and does not cover any of the coils 6a-d . Hence, only the L1 coil becomes 6a influenced by the A1 section of the Cu activator and its inductance value L1 is reduced to the lowest value Llow (nH). The coils 6b-d ( L2 , L3 and L4 ) are not subject to any influence of any part of the flux element 12th and show their respective maximum inductance values L2 , 3rd .4 of (or near about) Lhigh (nH).

If the activator rotates clockwise by 45 °, for example (not shown intermediate position between the positions from the 3a , b ), cover the sections A1 and A2 of the flow element 12th partly both coils 6a and 6b ( L1 or. L2 ), which gives both coils an intermediate inductance value L1 , 2 between Llow and Lhigh.

According to 3b covers the flow element 12th the L2 coil 6b Completely. This is called the 90 ° position of the angle of rotation D. viewed as the line connecting A1 and A2 now to the 90 ° position is aligned. The section A1 is now in quadrant Q2 above the circular disk 22nd and does not cover any coils 6a-d , the section A2 is in the quadrant Q1 above the coil 6b ( L2 ). So it just becomes the L2 coil 6b from the A2 section of the flow element 12th influenced.

According to 3c lies the flux element 12th completely over the L3 coil 6c , this is called the 180 ° angular position of the angle of rotation D. considered. The section A1 is in the quadrant Q3 and covers the coil 6C ( L3 ), the section A2 is in quadrant Q2. The sink L3 is below the A1 section of the flow element 12th influenced.

According to 3d is the flow element 12th positioned so that it completely covers the L4 coil 6d. This corresponds to the 270 ° angular position of the angle of rotation D. . In this case, the section is A1 in quadrant Q4 and the section A2 in the quadrant Q3 (Coil 6d, L4 ). The L4 coil 6d is under the influence of the section A2 of the flow element 12th .

In 4th is the course of the inductances L1-4 shown if - depending on the angle of rotation D. - the flux element the coils 6a-d partially or completely covered. The coil inductances L1-4 change over the angle of rotation D. according to the curves shown. The respective inductance value L1-4 is converted into a suitable electrical signal (mV), and then a microcontroller / ASIC (in the evaluation device 18th , not shown) used to indicate the middle position of the flow element 12th (Angle of rotation D. ) to estimate or determine. Here is the flow element 12th firmly attached to a rotating (non-metallic, not shown) disc. For this purpose, the latter is also rigidly attached to a rotating shaft of the rotor of an electrical machine (not shown). The part of the sensor assembly 2 out 1 on the other hand, it is fixed in place with respect to the stator of the machine. The angle of rotation D. the sensor arrangement 2 therefore gives the angle of rotation D. of the rotor to the stator. The assignment of the quadrants Q1-4 to the angles of rotation is in 4th registered. arrow 32 indicates the rotation of the flux element 12th clockwise.

5 shows an alternative embodiment of a sensor arrangement 2 , namely a Radial Type Inductive Rotor Angular-Position Measurement Sensor (Radial IRPS): Opposite the 1-3 A slight modification was made to allow the sensor arrangement 2 functions as a radial angular position sensor.

Here is according to 5a (comparable 1 ) instead of a non-metallic disc 22nd a non-metallic cylinder or cylinder jacket 28 of a straight circular cylinder is used. Its length L. or height corresponds to the difference between the radii R2-R1 of the circular disk 22nd in 1 . The radius of the cylinder depends, for example, on the electric motor on which the sensor arrangement is attached 2 should be used. The two PCBs or printed circuit boards 20a , b who have favourited the coils 6a-d are on the inside of the non-metallic cylinder or cylinder jacket 28 in the inner quadrant Q1 and Q3 arranged. The area 16 is therefore a circular cylinder jacket (radial inside).

The coil groups 4a , b thus each have the shape of a quarter of the circumference of a circular cylinder jacket.

According to 5b Another non-metallic cylinder is used 30th to do this, the activator or the flow element 12th on the outer surface of the second cylinder 30th to attach. The outer radius of the cylinder 30th is such that, when it is firmly connected to the rotor shaft, it is inside the cylinder jacket 28 rotates, with a predetermined vertical air gap (spacing gap a , in mm or) between the PCB reel 6a-d (radially inner surface) and the radially outer surface of the flow element 12th on the cylinder 30th is maintained.

For both versions ( 1-3 and 5 ) therefore lie on the surface 16 the spools 6a , b and the coils 6c , d each perpendicular to the circular path 14th side by side.

6th shows simulation results for the clockwise rotating flux element 12th according to the 1 to 3rd . It should be emphasized that the coils 6a (also "T1 / L1 ) and 6c (also "T3 / L3") as "Top" coils and the coils 6b (also "B2 / L2") and 6d (also "B4 / L4") as "bottom" coils together form a trapezoidal coil group 4a , b form and here two such coil groups 4a , b be used. Coil group 4a is in the quadrant Q1 , Coil group 4b in the quadrant Q3 placed. 6th shows the course of the inductances L1 to L4 over the angle of rotation D. .

7th shows in a table for which coils 6a-d (T1, B2, T3, B4) falling (top line 34 , indicated by the down arrow) or increasing (lower line 36 , indicated by the arrow pointing upwards) Inductance values ( L. in µH), i.e. tendencies. The spools 6a-d are specified using the above designations “T” for “Top” and “B” for “Bottom” and again in the respective quadrant columns Q1 and Q3 in which they are located. The rotation of the flow element 12th takes place clockwise again (from left to right in the table). 7th thus provides a status table for the sensor arrangement 2 The angle of rotation D. is shown as a rising angle (0 ° to 720 °).

It is very important to emphasize the following: For a rotation of the flux element 12th clockwise (lower line in the table, 7th ) shows the table for the rotation (Q1 -> Q2 -> Q3 -> Q4) sequentially for the T1, B2, T3 and B4 coils 4a-d increasing inductances (values).

For the counterclockwise rotation, the lower line of the table shows that sequentially the B4, T3, B2 and T1 coils 4a-d have increasing inductances (values).

With regard to the figures, it should be noted that the order of the quadrants differs from conventional numbering (common convention): Q1 , Q3 are conventionally numbered, while Q2 and Q4 are swapped.

The 8th shows accordingly 1 - 3rd an alternative sensor arrangement 2 with only one coil group 4a with two coils 6a , b and only one blank area 8a .

This extends over an empty angle E1 of 180 °. The coil group 4a extends across the quadrants Q1 , 2 over a coil angle S1 of 180 °, which is equal to the total angle G is. The arched thin / laminar flow element 12th (CU activator) extends over an angular extent W. of 360 °, the sections A1 , A2 each over arc lengths B1 , 2 of 180 ° each. The circular path 14th around the axis of rotation 10 is only indicated here by dashed lines. Otherwise the sensor arrangement is 2 accordingly or analogously to 1-3 constructed and operated like this. Although the coil group is here 4a only 180 ° of the circular disc 22nd covers, the sensor arrangement 2 the full 360 ° angle of rotation D. measure a rotor movement.

The spools 4a , b are on a single circuit board 20a (Circular ring segment) on the non-metallic circular disc 22nd (Circular ring).

List of reference symbols

2

Sensor arrangement

4a, b

Coil group

6a-d

Kitchen sink

8a, b

Empty area

10

Axis of rotation

12th

Flow element

14th

Circular path

16

area

18th

Evaluation device

20a, b

Circuit board

22nd

Circular disc

24a, b

Coil type

26th

hole

28

Cylinder jacket

30th

cylinder

32

arrow

34

Line (top)

36

Line (bottom)

L1-4

Inductors

D.

Rotation angle

W.

Angular expansion

S1.2

Spool angle

G

Total angle

E1,2

Empty angle

a

Spacing gap

Q1-4

quadrant

A1.2

section

B1.2

Arc length

L.

length

R1.2

radius

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Non-patent literature cited

• "Development of Eddy-Current Rotor Position Sensor, Markus Simon, Business Unit 8, SUMIDA Components & Modules GmbH, Presented at EVTeCand APE Japan on May 23, 2014, JSAE Paper No. 20144103 ‟[0002]

Claims (16)

Sensor arrangement (2) for detecting an angle of rotation (D) of a flux element (12) which can be rotated along a circular path (14) about an axis of rotation (10), - With at least one coil group (4a, b) interacting with the flux element (12), each with at least two coils (6a-d), - wherein the coil groups (6a-d) extend in a surface (16) concentrically surrounding the axis of rotation (10), - wherein the surface (16) runs parallel to and along the circular path (14), and a respective coil group (4a, b) is limited along the circular path (14) to a respective coil angle (S1,2), - where the coil angles (S1,2) of all coil groups (4a, b) add up to a total angle (G) of less than 360 °, - wherein at least one empty area (8a, b) is present along the circular path (14) which extends over a respective empty angle (E1,2), - With the flux element (12), which extends parallel to the surface (16) with the interposition of a spacing gap (a), - wherein the flux element (12) along the circular path (14) has an angular extent (W) which is greater than the largest coil angle (S1,2), - With an evaluation device (18) which is set up to determine the current inductance (L1-4) of each of the coils (6a-d) and a current angle of rotation (D) of the flux element (12) on the basis of at least two determined To determine inductances (L1-4). Sensor arrangement according to Claim 1 , characterized in that at least two coil groups (4a, b) are present, and along the circular path (14) there is at least one empty area (8a, b) between each two coil groups (4a, b). Sensor arrangement (2) according to one of the preceding claims, characterized in that the same number of coil groups (4a, b) and empty areas (8a, b) are arranged alternately along the circular path (14). Sensor arrangement (2) according to one of the Claims 2 to 3rd , characterized in that at least two of the coil angles (S1,2) are of the same size and / or at least two of the empty angles (E1,2) are of the same size. Sensor arrangement (2) according to one of the Claims 2 to 4th , characterized in that exactly two coil groups (4a, b) and exactly two empty areas (8a, b) are present. Sensor arrangement (2) according to one of the Claims 1 to 5 , characterized in that the total angle (G) is 180 ° and / or the angular extent (W) is 360 ° and / or at least one of the coil angles (S1,2) is 180 ° and / or at least one of the empty angles (E1,2 ) Is 180 °. Sensor arrangement (2) according to one of the Claims 2 to 5 , characterized in that the total angle (G) is 180 ° and / or the angular extent (W) is 180 ° and / or at least one of the coil angles (S1,2) is 90 ° and / or at least one of the empty angles (E1,2 ) Is 90 °. Sensor arrangement (2) according to one of the preceding claims, characterized in that the flow element (12) is designed to be contiguous along the circular path (14) or is divided into at least two adjoining or spaced apart sections (A1,2). Sensor arrangement (2) according to one of the preceding claims, characterized in that the angular extent (W) is at least as large as the largest sum of a coil angle (S1,2) and an adjacent empty angle (E1,2). Sensor arrangement (2) according to one of the Claims 2 to 9 , characterized in that there is at least one coil type (24a, b) for the same coils (6a-d) and at least two coil groups (4a, b) each contain one of the same coils (6a-d) which are rotationally symmetrical to the axis of rotation (10 ) are arranged. Sensor arrangement (2) according to Claim 10 , characterized in that a respective section (A1,2) of the flux element (12) is assigned to at least one type of coil (24a, b). Sensor arrangement (2) according to Claim 11 , characterized in that at least one of the sections (A1,2) is congruent with the assigned coil type (24a, b). Sensor arrangement (2) according to one of the preceding claims, characterized in that in at least one of the coil groups (4a, b) at least two of the coils (6a-d) lie next to one another in the surface (16) perpendicular to the circular path (14). Sensor arrangement (2) according to one of the preceding claims, characterized in that at least one of the coils (6a-d) has a shape which tapers along the circular path (14). Sensor arrangement (2) according to one of the preceding claims, characterized in that at least one of the coil groups (4a, b) has the shape of a circular ring segment or a circumferential section of a circular cylinder jacket. Sensor arrangement (2) according to one of the preceding claims, characterized in that the surface (16) has the shape of a disk transversely to the axis of rotation (10) or a jacket of a straight truncated circular cone or a jacket of a straight circular cylinder with respect to the axis of rotation (10).

Images