Inductive angle measuring mechanism
The inductive angle measuring mechanism addresses harmonic interference by employing sinusoidally arranged conductor tracks and an electronic circuit to enhance angular position measurement accuracy.
Patent Information
- Application Number
- JP2021017976
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2020-04-23
- Filing Date
- 2021-02-08
- Publication Date
- 2025-01-23
- Estimated Expiration
- 2041-02-08
AI Technical Summary
Inductive angle measuring mechanisms face challenges in accurately measuring relative angular positions due to interference from harmonics in the received signal.
The mechanism employs a scanning element and a scale element with sinusoidally arranged conductor tracks, featuring specific center-to-center distances and phase shifts to generate a signal free of disturbing harmonics, using a scanning element with excitation and receiving tracks and an electronic circuit to process the signal.
This design minimizes harmonics, reducing interpolation errors and enhancing the accuracy of angular position determination.
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Abstract
Description
[Technical field]
[0001] The invention relates to an inductive angle measuring arrangement for determining a relative angular position according to claim 1. [Background technology]
[0002] Inductive angle measuring devices are used as angle measuring devices, for example for determining the angular position of two machine parts that can rotate relative to one another. In inductive angle measuring devices, an excitation track and a receiving track, for example in the form of a conductor track, are often implemented on a common, usually multi-layer, printed circuit board, which is fixedly connected, for example, to the stator of the angle measuring device. A scale element is located opposite the printed circuit board, on which a graduation structure is implemented and which is non-rotatably connected to the rotor of the angle measuring device. If a time-alternating excitation current is applied to the excitation track, a signal that depends on the angular position is generated in the receiving track during the relative rotation of the rotor and stator. This signal is then further processed in the evaluation electronics.
[0003] Such inductive angle measuring devices are often used as measuring devices for electric drives to determine the relative movement or relative position of corresponding machine parts, with the generated angular position values of the subsequent electronics being supplied via a corresponding interface arrangement for controlling the drive.
[0004] In the applicant's EP 2 329 225 B1 an inductive angle measuring arrangement is described in which by averaging a relatively precise measurement result is achieved having lowered harmonics or frequencies, in particular the third order.
[0005] From EP 0 909 955 A2 an inductive angle sensor is known which has a short-circuit wire in a rotor element, which short-circuit wire can be scanned by a receiving coil, which receiving coil has a relatively long straight section. [Prior art documents] [Patent documents]
[0006] [Patent Document 1] EP2329225B1 [Patent Document 2] EP0909955A2 Summary of the Invention [Problem to be solved by the invention]
[0007] The problem underlying the invention is to provide an inductive angle measuring arrangement which allows accurate measurement of the relative angular position by filtering out harmonics from the signal received by the receiving conductor. [Means for solving the problem]
[0008] This problem is solved according to the invention by the features of claim 1. The inductive angle measuring device comprises a scanning element and a scale element. The scale element includes a graduation track that wraps around an axis and has a number of conductor groups that are electrically connected and arranged next to each other in the measurement direction such that adjacent conductor groups have a center-to-center distance in the measurement direction. Each conductor group has a first conductor section, a second conductor section, a third conductor section and a fourth conductor section. The four conductor sections run transversely to the measurement direction, i.e. with a directional component perpendicular to the measurement direction. The measurement direction often corresponds to a circumferential direction relative to the axis, i.e. around the axis. The first conductor section and the second conductor section are electrically connected to each other. Similarly, the third conductor section and the fourth conductor section are electrically connected to each other. Within one conductor group, the first conductor section is offset from the third conductor section in the measurement direction with a distance in the measurement direction. Additionally, within one conductor group, a fourth conductor section is arranged offset with respect to the second conductor section at a (same) distance, the distance being dimensioned to correspond to the center-to-center distance divided by a natural number M greater than or equal to 4. The scanning element has an excitation track and a receiving track with at least two receiving conductors, which have a sinusoidally circumferential, spatially periodic track with a period length corresponding to the center-to-center distance.
[0009] With this arrangement, a signal can be generated by a receiving conductor which is substantially free of disturbing or interfering harmonic (or overtone) components, the sinusoidal receiving conductor having no straight sections.
[0010] Typically, the scanning elements and the scale elements are arranged opposite each other and spaced apart by an axially or radially extending gap, and the receiving conductors are often arranged to have a phase shift relative to each other (e.g., a 90° phase shift).
[0011] Advantageously, the inductive angle measurement mechanism is configured such that the scanning element has two excitation tracks, each of which includes at least one conductor path, which excitation tracks extend in the measurement direction, i.e. along the measurement direction. In addition, the receiving track is arranged between the excitation tracks. The angle measurement mechanism further includes an electronic circuit, by means of which an excitation current can be generated in the excitation tracks. Advantageously, the excitation current in the at least two excitation tracks flows in the same direction at a certain point in time.
[0012] In a further aspect of the invention, the natural number M is 6 or greater. In the following, the center distances and the spacing of the conductor sections are given in angles, ie in degrees or fractions of an angle or in radians.
[0013] A conductor group is understood in the following to mean, in particular, a region on the scale element in which, over a section in the measuring direction having an extent corresponding to the center distance TP, there exists a path of the conductor section, in particular the path of the entire conductor, which corresponds to the section when rotated through the center distance TP or an integer multiple thereof. The scale element therefore has sections, in particular conductor groups, which are arranged periodically and repeatedly with a period corresponding to the center distance TP. The conductor groups are electrically connected to one another in series, so that an electrically closed graduation track exists, and in particular the conductor groups can be partial regions of a conductor that are formed in particular without joints.
[0014] The conductor group can be configured in such a way that the trajectories of the conductor sections therein are axially symmetrical with respect to a radially extending axis of symmetry. The scale element is advantageously designed in such a way that the four conductor sections each extend in a direction which has a radial component relative to the axis.
[0015] It is advantageous if the graduation track has a number N of conductor groups, with the center distance TP corresponding to the circumferential angle divided by the number N of conductor groups, i.e. TP=360° / N. In the same sense, this consideration can also be carried out in degrees, where TP=2π / N.
[0016] According to an advantageous embodiment of the invention, the distance in the measurement direction between two directly non-adjacent conductor sections in one conductor group corresponds to half the center distance. In particular, in one conductor group, a first conductor section is offset in the measurement direction from a fourth conductor section by a distance that corresponds to half the center distance. In addition, in one conductor group, a third conductor section is offset in the measurement direction from a second conductor section by a distance that corresponds to half the center distance.
[0017] Advantageously, the first and second conductor sections and the first and second coupled conductor sections are sections of a first conductor. Furthermore, the first and second conductor sections are electrically coupled to each other in series by the first and second coupled conductor sections. The third and fourth conductor sections and the third and fourth coupled conductor sections are sections of a second conductor, and the third and fourth conductor sections are electrically coupled to each other in series by the third and fourth coupled conductor sections.
[0018] The coupling conductor sections preferably extend in a direction which has a directional component parallel to the measuring direction. Advantageously, the four conductor sections are arranged in a flat plane.
[0019] In a further embodiment of the invention, the coupling conductor sections are arranged alternately radially inward and radially outward relative to the conductor sections in the measuring direction. Alternatively, the conductor sections can also be arranged on a surrounding surface, for example on the side of a cylinder. In this case, the four conductor sections extend in a direction with an axial component (relative to the (rotation) axis). In this case, the scale element has a curved surface on which the graduation track is arranged. In this case, the conductor group can be designed in such a way that the paths of the conductor sections therein are axially symmetrical with respect to an axis of symmetry that runs parallel to the (rotation) axis.
[0020] According to a further embodiment of the invention, the four conductor track sections have a width in the measuring direction of less than 300 μm, in particular less than 200 μm or less than 150 μm. In a further embodiment of the invention, the conductor group has, in addition to the four conductor sections, a fifth, a sixth, a seventh and an eighth conductor section. The fifth and sixth conductor sections are electrically connected to each other. Similarly, the seventh and eighth conductor sections are electrically connected to each other. In one conductor group, the first conductor section is offset from the fifth conductor section with a distance in the measurement direction, and the third conductor section is offset from the seventh conductor section with a distance in the measurement direction. The respective distances correspond to the center distance divided by a natural number M greater than or equal to six.
[0021] Advantageously, the distance between the first and fifth conductor sections is as large as the distance between the third and seventh conductor sections. In particular, when the four conductor sections are arranged on a flat surface, it is advantageous for at least two receiving conductors to be arranged on the flat surface, in particular with the faces of the at least two receiving conductors being arranged axially offset with respect to the faces of the four conductor sections.
[0022] Advantageous configurations of the invention can be seen from the dependent claims. Further details and advantages of the inductive angle measurement mechanism according to the invention become apparent from the following description of several exemplary embodiments based on the attached drawings. [Brief description of the drawings]
[0023] [Figure 1] FIG. 2 is a plan view of a scanning element according to a first exemplary embodiment. [Diagram 2] FIG. 2 is a plan view of a scale element according to a first exemplary embodiment. [Diagram 3] FIG. 2 is a detailed view of a scale element according to a first exemplary embodiment. [Figure 4] FIG. 13 is a detailed view of a scale element according to a second exemplary embodiment. [Diagram 5] FIG. 13 is a detailed view of a scale element according to a third exemplary embodiment. [Figure 6] FIG. 13 is a detailed view of a scale element according to the fourth exemplary embodiment. [Figure 7] FIG. 13 is a plan view of a scanning element according to a fifth exemplary embodiment. [Figure 8] FIG. 13 is a plan view of a scale element according to a fifth exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The invention is described on the basis of an angular measurement mechanism determined to capture the angular position φ between a scanning element 1 (FIG. 1) and a scale element 2 (FIG. 2) or scale which is rotatable relatively about an axis A, which in the figures is oriented perpendicular to the respective drawing plane. A circumferential direction can therefore be defined as the measurement direction U.
[0025] The scanning element 1 is implemented as a printed circuit board with several layers and is used for scanning the scale element 2. The scanning element 1 shown in FIG. 1 has four receiving conductors 1.11, 1.12, 1.13, 1.14 arranged in the receiving track 1.1 and the excitation tracks 1.3, 1.4. In particular, the receiving conductors 1.11, 1.12, 1.13, 1.14 are arranged radially between the excitation tracks 1.3, 1.4. In addition to this, the receiving conductors 1.11, 1.12, 1.13, 1.14 run in different planes with through vias, which avoids undesirable short circuits at the intersections. In the illustrated exemplary embodiment, at least two layers are provided in the printed circuit board structure. The receiving conductors 1.11, 1.12, 1.13, 1.14 have a spatially periodic trajectory that is substantially sinusoidally or sinusoidally shaped. In this respect, the abscissa x (indicated by the arrows on the receiving conductors 1.11, 1.12, 1.13, 1.14 in FIG. 1) of the associated sinusoidal lines runs along a circular line around the axis A. In the exemplary embodiment presented here, the receiving conductors 1.11, 1.12, 1.13, 1.14 each run through or wrap around 16 complete sinusoidal periods (16·2π or 16·360°) and have a length of 16·2π or 16·360° or 16·PL. The receiving conductors 1.11, 1.12, 1.13, 1.14 are offset relative to one another along the measuring direction U. In the exemplary embodiment presented here, adjacent receiving conductors 1.11, 1.12, 1.13, 1.14 are offset relative to one another by 1 / 8 of a complete sinusoidal period (π / 4 or 45° for the abscissa x). The receiving conductors 1.11, 1.12, 1.13, 1.14 are electrically connected so as to ultimately result in signals that are phase shifted by 90°. In the exemplary embodiment presented here, the receiving conductors 1.11, 1.12, 1.13, 1.14 each have 16 periods along a circular line, so that each of the receiving conductors 1.11, 1.12, 1.13, 1.14 has a period length PL of 22.5°. In the following, the lengths in the circumferential or measuring direction U are presented by angular dimensions.
[0026] In Fig. 2, the scale element 2 is shown in plan view. In the illustrated exemplary embodiment, the scale element 2 consists of a substrate, which is made of epoxy resin, on which a first conductor track 2.1 and a second conductor track 2.2 are arranged in the graduation track TS1. In the illustrated example, copper is applied to the substrate as material for the first conductor track 2.1 and the second conductor track 2.2. The conductor tracks 2.1 and the second conductor track 2.2 each have a width of 150 μm.
[0027] The graduation track TS1 is centered on the axis A and is arranged around the axis A in the measuring direction U. The first conductor track 2.1 and the second conductor track 2.2 have a meandering path and are seamless.
[0028] The graduation track TS1 (i.e. the associated first and second conductors 2.1 and 2.2) can be divided into so-called conductor groups TG. In the exemplary embodiment presented here, the graduation track TS1 comprises a total of 16 conductor groups TG, the center distance TP of the conductor groups TG being 22.5° (360° / 16) or 0.39 in radians (2π / 16). In the exemplary embodiment presented here, the center distance TP on the scale element 2 therefore corresponds to the period length PL on the scanning element 1.
[0029] PL=TP The conductor group TG is a section on the graduation track TS1 which extends over an angular interval corresponding to the center distance TP such that the trajectories of the first conductor 2.1 and the second conductor 2.2 of adjacent conductor groups TG coincide if one of them is rotated around the axis A by an amount corresponding to the center distance TP.
[0030] In FIG. 3, one conductor group TG is shown in detail. One conductor group TG extends in the circumferential direction between radial lines R, which are also spaced apart by 22.5° (2·TP / 2). In the exemplary embodiment shown, such a conductor group TG has a first conductor section 2.11, a second conductor section 2.12, a third conductor section 2.21 and a fourth conductor section 2.22, which run transversely to the measuring direction U, i.e. radially relative to the axis A, and each have a width of 150 μm. In FIG. 3, the widths of the conductor sections 2.11, 2.12; 2.21, 2.22 are shown with a slightly pyramidal shape and decreasing towards the axis A. In this embodiment, the width of 150 μm refers to the maximum width of the conductor sections 2.11, 2.12; 2.21, 2.22. The four conductor sections 2.11, 2.12; 2.21, 2.22 can be assigned to the two conductor section pairs P1112, P2122. The first conductor 2.1 thus has two radial conductor sections 2.11, 2.12, i.e. the first conductor section 2.11 and the second conductor section 2.12, which are assigned to the conductor section pair P1112. The second conductor 2.2 has two radial conductor sections 2.21, 2.22 (here the third conductor section 2.21 and the fourth conductor section 2.22) which are assigned to the conductor section pair P2122. The first conductor 2.1 and the second conductor 2.2 further have coupling conductor sections 2.13, 2.14, 2.23, 2.24 which in the exemplary embodiment presented here extend in the circumferential or measuring direction U and electrically interconnect the radial conductor sections 2.11, 2.12; 2.21, 2.22 in one conductor section pair P1112, P2122. In particular, the first conductor 2.1 comprises a first coupling conductor section 2.13 and a second coupling conductor section 2.14, so that the first conductor section 2.11 and the second conductor section 2.12 are electrically interconnected in series by the first and second coupling conductor sections 2.13, 2.14. Likewise, the second conductor 2.2 comprises a third coupling conductor section 2.23 and a fourth coupling conductor section 2.24.The third and fourth coupling conductor sections 2.23, 2.24 electrically couple the third and fourth conductor sections 2.21, 2.22 to each other in series.
[0031] The graduation track TS1 thus consists of a periodic sequence of conductive conductor sections 2.11, 2.12; 2.21, 2.22 between which non-conductive graduation areas are arranged. The conductor sections 2.11, 2.12; 2.21, 2.22 belonging to one and the same conductor 2.1, 2.2 are electrically connected to one another in a series connection.
[0032] The radial conductor sections 2.11, 2.12; 2.21, 2.22 belonging to different conductor section pairs P1112, P2122 are each offset in the circumferential direction by a distance d12. This means that the two directly adjacent radial conductor sections 2.11, 2.12 of the first conductor 2.1 are each offset in the circumferential direction by a distance d12 with respect to the two radial conductor sections 2.21, 2.22 of the second conductor 2.2. In other words, within one conductor group TG, the first conductor section 2.11 is offset in the measuring direction U by a distance d12 with respect to the third conductor section 2.21 and the fourth conductor section 2.22 is offset in the measuring direction U by a distance d12 with respect to the second conductor section 2.12. In the exemplary embodiment presented here, the distance d12 is 1 / 6 TP. The distance d12 thus corresponds to the center-to-center distance TP divided by a natural number M, here M=6.
[0033] d12=TP / 6 The first conductor section 2.11 of the first conductor 2.1 is offset in the measuring direction U with a distance d1122 from the fourth conductor section 2.22, i.e. with a distance d2112 from the fourth conductor section 2.22, which is not directly adjacent to the first conductor section 2.11 and belongs to the second conductor 2.2. Similarly, the third conductor section 2.21 of the second conductor 2.2 is offset in the measuring direction U with a distance d2112 from the second conductor section 2.12, i.e. with a distance d2112 from the second conductor section 2.12, which is not directly adjacent to the third conductor section 2.21 and belongs to the first conductor 2.1. In this respect, both the distance d1122 and the distance d2112 correspond to half the center distance TP.
[0034] d1122=d2112=TP / 2 Between the radial lines R, the conductor sections 2.11, 2.12; 2.21, 2.22 are arranged axially symmetrically with respect to a central radial axis of symmetry. The coupling conductor sections 2.13, 2.14, 2.23, 2.24 are also arranged axially symmetrically with respect to the radial line R.
[0035] In the assembled state, the scanning element 1 and the scale element 2 are axially opposed to each other, so that the axis A runs through the center points of both elements, and when the scale element 2 and the scanning element 1 rotate relative to each other, signals that depend on the respective angular position can be generated by inductive effects in the receiving conductors 1.11, 1.12, 1.13, 1.14. A prerequisite for the generation of corresponding signals is that the excitation tracks 1.3, 1.4 generate a time-varying electromagnetic excitation field in the area of the graduation track TS1 to be scanned. In the illustrated exemplary embodiment, the excitation tracks 1.3, 1.4 are formed as a number of individual conductors that carry a current in parallel planes. The scanning element 1 has an electronic circuit, which includes, for example, an ASIC chip. This electronic circuit of the scanning element 1 serves not only as an evaluation element but also as an excitation control element, under the control of which an excitation current is generated and which then flows through the excitation tracks 1.3, 1.4 or the individual conductors. Both excitation tracks 1.3, 1.4 are therefore energised by one and the same excitation control element.
[0036] If excitation currents flow in the excitation tracks 1.3, 1.4 in the same direction, a tubular or cylindrically oriented electromagnetic field is generated around the respective excitation track 1.3, 1.4. The field lines of this resulting electromagnetic field run around the excitation tracks 1.3, 1.4 in the form of concentric circles, the direction of the field lines depending, as is known, on the current direction in the excitation tracks 1.3, 1.4. In this regard, the current directions I13, I14 (FIG. 1) of the excitation tracks 1.3, 1.4 or the corresponding connections of the excitation tracks 1.3, 1.4 should be selected in the same direction, so that the field lines in the area of the receiving track 1.1 are directed in the opposite direction. The current flow in the excitation tracks 1.3, 1.4 induces currents in the first conductor track 2.1 and the second conductor track 2.2 of the scale element 2, respectively, which have the current directions I21, I22 (FIG. 2). The current direction I21 in the first conductor track 2.1 and the current direction I22 in the second conductor track 2.2 of the scale element 2 are parallel to each other (but not oppositely or antiparallel). Since the excitation current is alternating, the considerations related to the current directions I13, I14; I21, I22 only apply at one and the same time.
[0037] The first conductor 2.1 and the second conductor 2.2 run in a meandering manner, intertwined with one another. In particular, due to the dimensioning of the spacings d12, d1122, d2112 of the conductor sections 2.11, 2.12; 2.21, 2.22, in conjunction with the sinusoidal trajectories of the receiving conductors 1.11, 1.12, 1.13, 1.14, in the exemplary embodiment presented here, the signals generated by the receiving conductors 1.11, 1.12, 1.13, 1.14 have almost no third harmonics (or overtones) and practically no even harmonics. This minimizes the interpolation errors in determining the angular position value.
[0038] A further embodiment of the invention (second exemplary embodiment) is described on the basis of figure 4. This embodiment differs substantially from the first exemplary embodiment in that instead of the coupling conductor sections 2.13, 2.14, 2.23, 2.24 (figure 3) with their respective parallel tracks, integral coupling conductor sections 2.23', 2.24' are now provided through which all induced currents can flow.
[0039] According to the third exemplary embodiment of Fig. 5, the graduation track TS1 can include not only the first conductor 2.1 and the second conductor 2.2, but also the third conductor 2.3 and the fourth conductor 2.4. Accordingly, in this exemplary embodiment, there are eight conductor sections 2.11, 2.12; 2.21, 2.22; 2.31, 2.32; 2.41, 2.42, which run transversely to the measuring direction U, i.e. radially to the axis A. The conductor group TG thus additionally comprises here the fifth conductor section 2.31, the sixth conductor section 2.32, the seventh conductor section 2.41 and the eighth conductor section 2.42, respectively.
[0040] In this case, within one conductor group TG, the first conductor section 2.11 is offset relative to the fifth conductor section 2.31 by a distance d13 in the measurement direction U. In addition, the third conductor section 2.21 is offset relative to the seventh conductor section 2.41 by a distance d24 in the measurement direction U.
[0041] 3 can also be assigned to the two conductor section pairs P3132, P4142. The third conductor 2.3 thus has two radial conductor sections 2.31, 2.32 assigned to the conductor section pair P3132, and the fourth conductor 2.4 has two radial conductor sections 2.41, 2.42 assigned to the conductor section pair P4142. The third conductor 2.3 and the fourth conductor 2.4 also have coupling conductor sections 2.33, 2.34, 2.43, 2.44 which in the exemplary embodiment presented run in the circumferential direction and electrically interconnect the radial conductor sections 2.31, 2.32; 2.41, 2.42 in one conductor section pair P3132, P4142. The graduation track TS1 thus also in this exemplary embodiment consists of a periodic sequence of conductive conductor sections 2.11, 2.12; 2.21, 2.22; 2.31, 2.32; 2.41, 2.42 between which non-conductive graduation areas are arranged. The distance d12 between the conductor sections 2.11, 2.21 or between the conductor sections 2.12, 2.22 of the first conductor 2.1 and the second conductor 2.2 is also 1 / 6TP (natural number M=6) in this exemplary embodiment. d12=TP / 6 It is.
[0042] Furthermore, the distance d13 between the conductor sections 2.11, 2.31 of the first conductor 2.1 or the distance d13 between the conductor sections 2.12, 2.32 of the third conductor 2.3 is 1 / 10TP (natural number M=10), and therefore d13=TP / 10 It is.
[0043] Furthermore, d24 = d13, that is, d24=TP / 10 It is.
[0044] In addition, also in the third exemplary embodiment, two directly non-adjacent conductor sections 2.11, 2.12; 2.21, 2.22; 2.31, 2.32; 2.41, 2.42 of one conductor group TG each have a spacing that corresponds to half the center distance TP.
[0045] The fifth conductor section 2.31 of the third conductor 2.3 is offset with respect to the fourth conductor section 2.22, i.e. with respect to the fourth conductor section 2.22, which is not arranged directly adjacent to the fifth conductor section 2.31 and belongs to the second conductor 2.2, by a distance TP / 2 in the measuring direction U. The same applies, for example, to the second conductor section 2.12 and the seventh conductor section 2.41 (distance TP / 2).
[0046] All conductors 2.1 to 2.4 run in a meandering manner and are intertwined with one another. In the exemplary embodiment presented here, not only the third harmonic but also the fifth harmonic and all even harmonics are filtered out of the signals generated by the receiving conductors 1.11, 1.12, 1.13, 1.14.
[0047] In FIG. 6, an alternative form (fourth exemplary embodiment) of the scale element 2 is shown. There, two conductor tracks 2.1, 2.2 are provided according to the first exemplary embodiment, where the first conductor track 2.1 and the second conductor track 2.2 are not formed as electrically separate conductors, i.e. are not arranged electrically purely in parallel, but are connected in series. For this purpose, on two planes of the printed circuit board of the scale element 2 or by means of a second copper layer, the coupling conductor tracks 2.5, 2.6 are arranged. The coupling conductor tracks 2.5, 2.6 connect the two conductor tracks 2.1, 2.2 by means of microvias (very small diameter connection holes) in such a way that they are connected to each other in series. This arrangement has the advantage, among other things, that different currents can not flow in the conductor tracks 2.1, 2.2. Such an effect (currents of different magnitudes) can limit harmonic filtering or filtering of harmonics.
[0048] A fifth exemplary embodiment is shown in Figures 7 and 8. According to Figure 7, the scanning element 1 here additionally comprises another further inner receiving track 1.2, which comprises four receiving conductors 1.21, 1.22, 1.23, 1.24. The receiving conductors 1.21, 1.22, 1.23, 1.24 have a substantially sinusoidally or sinusoidally shaped, spatially periodic trajectory, in which the abscissas of the sine wave lines run along a circular line around the axis A. The receiving conductors 1.21, 1.22, 1.23, 1.24 are arranged according to the first exemplary embodiment, i.e. offset by 45° relative to one another, and therefore, in the case of a corresponding electrical connection, can result in signals that are phase-shifted by 90°. The receiving conductors 1.21, 1.22, 1.23, 1.24 of the inner receiving track 1.2 each have three periods along a circular line.
[0049] Moreover, the scanning element 1 according to the fifth exemplary embodiment includes a further excitation track 1.5 which includes a plurality of excitation conductors or excitation conductor tracks. The current direction of the excitation track 1.5 should be selected in the opposite direction with respect to the current direction of the excitation tracks 1.3, 1.4.
[0050] 8, the scale element 2 according to the fifth exemplary embodiment comprises a further inner graduation track TS2, which in the illustrated embodiment consists of graduation areas 2.7 which are provided with an electrically conductive material, here copper. No electrically conductive material is arranged between the graduation areas 2.7.
[0051] By means of the receiving track 1.1 a relatively high resolution angular position value for the relative angular position can be generated, while by means of the further receiving track 1.2 a relatively coarse angular position value can be generated. In an electronic circuit a correlation is made between the fine and the relatively coarse angular position values, as a result of which the circuit generates a high resolution absolute angular position value. [Explanation of symbols]
[0052] 1 Scanning Element 1.1 Received Tracks 1.11, 1.12, 1.13, 1.14 Receiving conductor 1.3, 1.4 Excitation track 2 Scale elements 2.1 First conductor path 2.11 First conductor section 2.12 Second conductor section 2.13, 2.23' First coupling conductor section 2.14, 2.24' Second coupling conductor section 2.2 Second conductor path 2.21 Third conductor section 2.22 Fourth conductor section 2.23, 2.23' Third coupling conductor section 2.24, 2.24' Fourth coupling conductor section 2.31 Fifth conductor section 2.32 Sixth conductor section 2.41 Seventh conductor section 2.42 Eighth conductor section A-axis d12, d1122, d2112, d13, d24 spacing PL period length TG conductor group TP center distance TS1 Scale track U measurement direction
Claims
1. An inductive angle measurement mechanism comprising a scanning element (1) and a scale element (2), the scale element (2) comprises a graduation track (TS1) wrapping around an axis (A), the graduation track (TS1) having a plurality of conductor groups (TG), the conductor groups (TG) being electrically coupled and arranged next to each other in the measuring direction (U) such that adjacent conductor groups (TG) have a center distance (TP) in the measuring direction (U), The conductor path groups (TG) each include a first conductor section (2.11), a second conductor section (2.12), a third conductor section (2.21) and a fourth conductor section (2.22), said conductor sections (2.11, 2.12; 2.21, 2.22) extending transversely to the measuring direction (U), the first conductor section (2.11) and the second conductor section (2.12) are electrically connected to each other, and the third conductor section (2.21) and the fourth conductor section (2.22) are electrically connected to each other, Within one conductor group (TG), the first conductor section (2.11) faces the third conductor section (2.21), and the fourth conductor section (2.22) is offset from the second conductor section (2.12) by a distance (d12) in the measuring direction (U), The distance (d12) corresponds to the center-to-center distance (TP) divided by a natural number (M) equal to or greater than 4; an inductive angle measuring arrangement, in which the scanning element (1) has an excitation track (1.3, 1.4) and a receiving track (1.1) with at least two receiving conductors (1.11, 1.12, 1.13, 1.14), the receiving conductors (1.11, 1.12, 1.13, 1.14) having a trajectory which is sinusoidal and has a period length (PL) which corresponds to the centre distance (TP).
2. 2. An inductive angle measurement arrangement according to claim 1, characterized in that the scanning element (1) has at least two excitation tracks (1.3, 1.4), each of which comprises at least one conductor path, the excitation tracks (1.3, 1.4) extending in a measuring direction (U) and the receiving track (1.1) being arranged between the excitation tracks (1.3, 1.4), 13. An inductive angle measurement mechanism, the angle measurement mechanism further comprising an electronic circuit, by means of which an excitation current can be generated in the excitation track (1.3, 1.4).
3. 3. An inductive angle measurement mechanism according to claim 2, wherein the excitation currents in at least two excitation tracks (1.3, 1.4) flow in the same direction at a given time.
4. 4. The inductive angle measurement according to claim 1, wherein the natural number (M) is 6 or more.
5. 5. The inductive angle measuring mechanism according to claim 1, wherein the graduation track (TS1) has a certain number (N) of conductor groups (TG) and the center distance (TP) corresponds to a circumferential angle divided by the number (N) of conductor groups (TG).
6. 6. An inductive angle measuring mechanism according to claim 1, further comprising: An inductive angle measuring mechanism, in which the distance (d1122, d2112) in the measuring direction (U) between two directly non-adjacent conductor sections (2.11, 2.12; 2.21, 2.22) of (TG) corresponds to half the center distance (TP).
7. 7. An inductive angle measurement mechanism according to any one of claims 1 to 6, the first conductor section (2.11) and the second conductor section (2.12) as well as the first coupling conductor section (2.13, 2.23') and the second coupling conductor section (2.14, 2.24') are sections of a first conductor (2.1), the first conductor section (2.11) and the second conductor section (2.12) are electrically coupled to each other in series by the first coupling conductor section (2.13, 2.23') and the second coupling conductor section (2.14, 2.24'), and 2. An inductive angle measuring arrangement, wherein the third conductor section (2.21) and the fourth conductor section (2.22) as well as the third coupling conductor section (2.23, 2.23') and the fourth coupling conductor section (2.24, 2.24') are sections of a second conductor (2.2), and the third conductor section (2.21) and the fourth conductor section (2.22) are electrically coupled to each other in series by the third coupling conductor section (2.23, 2.23') and the fourth coupling conductor section (2.24, 2.24').
8. An inductive angle measurement mechanism according to any one of claims 1 to 7, the first conductor section (2.11) and the second conductor section (2.12) as well as the first coupling conductor section (2.13, 2.23') and the second coupling conductor section (2.14, 2.24') are sections of a first conductor (2.1), the first conductor section (2.11) and the second conductor section (2.12) are electrically coupled to each other in series by the first coupling conductor section (2.13, 2.23') and the second coupling conductor section (2.14, 2.24'), and 2. An inductive angle measuring arrangement, wherein the coupling conductor sections (2.13, 2.14, 2.23, 2.24; 2.23', 2.24') extend in a direction having a directional component parallel to the measuring direction (U).
9. 9. An inductive angle measurement mechanism according to any one of claims 1 to 8, the first conductor section (2.11) and the second conductor section (2.12) as well as the first coupling conductor section (2.13, 2.23') and the second coupling conductor section (2.14, 2.24') are sections of a first conductor (2.1), the first conductor section (2.11) and the second conductor section (2.12) are electrically coupled to each other in series by the first coupling conductor section (2.13, 2.23') and the second coupling conductor section (2.14, 2.24'), and The inductive angle measuring mechanism, in which the coupling conductor sections (2.13, 2.14, 2.23, 2.24; 2.23', 2.24') are arranged alternately radially inward and radially outward with respect to the conductor sections (2.11, 2.12; 2.21, 2.22) in the measuring direction (U).
10. 10. The inductive angle measuring arrangement according to claim 1 , wherein the four conductor track sections (2.11, 2.12; 2.21, 2.22) have a width in the measuring direction (U) of less than 300 μm.
11. 11. The inductive angle measuring arrangement according to claim 1, wherein the conductor group (TG) has a fifth conductor section (2.31), a sixth conductor section (2.32), a seventh conductor section (2.41) and an eighth conductor section (2.42), the conductor sections (2.31, 2.32; 2.41, 2.42) extending transversely to the measuring direction (U), the fifth conductor section (2.31) and the sixth conductor section (2.32) are electrically connected to each other, and the seventh conductor section (2.41) and the eighth conductor section (2.42) are electrically connected to each other, Within one conductor group (TG), the first conductor section (2.11) is offset from the fifth conductor section (2.31) in the measuring direction (U) by a distance (d13), and the third conductor section (2.21) is offset from the seventh conductor section (2.41) in the measuring direction (U) by a distance (d24), An inductive angle measurement mechanism, wherein each of the intervals (d13, d24) corresponds to the center distance (TP) divided by a natural number (M) greater than or equal to 6.
12. 12. The inductive angle measurement mechanism according to claim 11, wherein the distance (d13) between the first conductor section (2.11) and the fifth conductor section (2.31) is the same as the distance (d24) between the third conductor section (2.21) and the seventh conductor section (2.41).
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