Induction type angle measuring device

Abstract

The invention relates to an inductive angle measuring device comprising a scanning element and a scale element which is rotatable relative to the scanning element. In the first receiver track, the scanning element comprises a first receiver conductor track by means of which a first signal can be generated and a second receiver conductor track by means of which a second signal can be generated, the first and second signals having a first phase offset from one another. The scanning element further comprises a fifth receiver conductor path, a sixth receiver conductor path, a seventh receiver conductor path and an eighth receiver conductor path, the fifth and sixth receiver conductor paths being connected in series with one another such that a first total signal can be generated by means of the fifth and sixth receiver conductor paths. The seventh and eighth receiver tracks are likewise connected to one another in series such that a second total signal can be generated by means of the seventh and eighth receiver tracks. The first total signal and the second total signal have a second phase offset from each other.

Description

Technical Field

[0001] The invention relates to an inductive angle measuring device according to the invention.

[0002] Inductive angle measuring devices are used to determine the angular position of machine parts that can rotate relative to one another. In inductive position measuring devices, an exciter track and a receiver track, for example in the form of conductor tracks, are usually applied to a common, usually multilayered, printed circuit board, which is fixedly connected, for example, to the stator of the position measuring device. Opposite the printed circuit board is a scale element, to which a graduation structure is applied and which is fixedly connected to the movable part of the position measuring device. If a temporally alternating excitation current is applied to the exciter track, position-dependent signals are generated in the receiver track during the relative movement between the scale element and the scanning element. These signals are then processed further in evaluation electronics. Background Art

[0003] EP 1 715 298 B1 discloses an inductive angle measuring device having an inner and an outer graduated track which have a different number of signal periods, so that in cooperation with an associated scanning element an absolute determination of the angular position is possible. Summary of the invention

[0004] The object of the present invention is to provide a scanning element which is compact and can be produced cost-effectively for relatively precise operation of an inductive angle measuring device.

[0005] This object is achieved according to the invention by the features of the invention.

[0006] Correspondingly, the inductive angle measuring device comprises a scanning element and a scale element rotatable around an axis relative to the scanning element. The scale element has a first scale track and a second scale track, the first scale track has a first scale structure, the first scale structure is periodically arranged along the circumferential direction around the axis, and the second scale track has a second scale structure, and the second scale structure is also periodically arranged along the circumferential direction. The scanning element has an exciter track and a first receiver track and a second receiver track. The first receiver track comprises a first receiver printed conductor and a second receiver printed conductor. The first receiver printed conductor and the second receiver printed conductor extend periodically, especially with a constant first period length, along a first circumferential line with a first radius. The first receiver printed conductor and the second receiver printed conductor are arranged in a staggered manner relative to each other in the circumferential direction, so that a first signal can be generated by the first receiver printed conductor and a second signal can be generated by the second receiver printed conductor. The first signal and the second signal have a first phase offset relative to each other. The second receiver track comprises a fifth receiver printed conductor, a sixth receiver printed conductor, a seventh receiver printed conductor and an eighth receiver printed conductor. The fifth receiver conductor track, the sixth receiver conductor track, the seventh receiver conductor track and the eighth receiver conductor track are respectively extended periodically along a second circumferential line having a second radius, in particular with a constant second period length. The fifth receiver conductor track, the sixth receiver conductor track, the seventh receiver conductor track and the eighth receiver conductor track are extended along the circumferential direction and are respectively arranged in the circumferential direction offset relative to each other. The fifth receiver conductor track and the sixth receiver conductor track are connected in series with each other so that a first total signal can be generated by the fifth receiver conductor track and the sixth receiver conductor track. The seventh receiver conductor track and the eighth receiver conductor track are also connected in series with each other so that a second total signal can be generated by the seventh receiver conductor track and the eighth receiver conductor track. The first total signal and the second total signal have a second phase offset with each other.

[0007] The scanning element is used in the angle measuring device to determine an angular position relative to a scale element, wherein the scale element is arranged rotatably about the axis relative to the scanning element, so that the measuring direction represents a circumferential direction relative to the axis.

[0008] Advantageously, the second period length is greater than the first period length. Therefore, the second receiver track provides relatively less high-resolution angular position information and is therefore often referred to as a coarse track. Correspondingly, the first receiver track can also be referred to as a fine track, since it generates higher-resolution angular position information.

[0009] In another embodiment of the present invention, the first phase offset PH1 is one quarter of the first constant period length λ1 (PH1=1 / 4·λ1). Similarly, the second phase offset PH2 can be one quarter of the second constant period length λ2 (PH2=1 / 4·λ2). Here, the period lengths λ1, λ2 are expressed in degrees or radians and are related to the center angle around the axis A. Therefore, the first phase offset PH1 and the second phase offset PH2 are related to the corresponding period lengths λ1, λ2 and can therefore be expressed as a fraction of the related period lengths λ1, λ2.

[0010] In a further embodiment of the invention, the first receiver track has a first number n1 of receiver conductor tracks and the second receiver track has a second number n2 of receiver conductor tracks. It applies here that the first number n1 is smaller than the second number n2 (n1<n2).

[0011] Advantageously, the second number n2 is at least twice as large as the first number n1 (n2 ≥ 2·n1), in particular exactly twice as large as the first number n1 (n2 = 2·n1).

[0012] In particular, the first radius R1 of the first circumferential line and the second radius R2 of the second circumferential line are different in size. Advantageously, the second radius R2 is smaller than the first radius R1 (R2<R1).

[0013] In a further embodiment of the invention, the scanning element comprises a first exciter track and a second exciter track, wherein the first receiver track is surrounded radially on the outside by the first exciter track and radially on the inside by the second exciter track. In contrast, the second receiver track is surrounded only on one side by the second exciter track.

[0014] Advantageously, the scanning element is designed so that the fifth receiver conductor track and the sixth receiver conductor track extend periodically with a constant second period length λ2 and are also arranged offset relative to each other in a circumferential direction with an angle offset φ2, wherein the angle offset φ2 is at most 1 / 16 of the second period length (φ2≤1 / 16·λ2).

[0015] Advantageously, the seventh receiver conductor track and the eighth receiver conductor track extend periodically with a constant second period length λ2 and are arranged offset relative to one another in the circumferential direction by an angular offset φ2. The angular offset φ2 between the seventh receiver conductor track and the eighth receiver conductor track is advantageously at most 1 / 16 of the second period length λ2, so that: φ2≤1 / 16·λ2 applies.

[0016] In a further embodiment of the invention, the scanning element is designed as a circuit board, wherein the exciter track, the first receiver track and the second receiver track extend in less than four conductive layers, i.e., in less than four planes. The conductive layers are structured such that the receiver conductor tracks are formed by these conductive layers. Furthermore, the excitation lines of the exciter track are generated by the structuring of the conductive layers. The scanning element can be designed in particular as a circuit board, wherein the exciter track, the first receiver track and the second receiver track extend in exactly two conductive layers.

[0017] Advantageously, the scanning element is designed such that the first receiver track and / or the second receiver track extends over the entire circumference around the axis. That is, at least one of the receiver conductor tracks of the receiver track in question is always present over 360°, so that every arbitrary radial line starting from a center point on the axis intersects at least one receiver conductor track. The first receiver track and / or the second receiver track thus has no gaps over the entire circumference.

[0018] Advantageous developments of the invention are revealed in the dependent claims.

[0019] Further details and advantages of the scanning element according to the invention emerge from the following description of exemplary embodiments with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A perspective view showing an angle measuring device comprising a scanning element and a scale element,

[0021] Figure 2 A top view of the scale element is shown,

[0022] Figure 3 A top view showing one side of the scanning element,

[0023] Figure 4 A top view showing a portion of a scanning element,

[0024] Figure 5 shows a plan view of a portion of a scanning element, wherein, among other things, a plurality of receiver conductor tracks are concealed,

[0025] Figure 6 a schematic diagram showing a receiver conductor track of a first receiver track in an expanded view,

[0026] Figure 7 a schematic diagram showing a receiver conductor track of a second receiver track in an expanded view,

[0027] Figure 8 shows the signal of the receiver conductor track of the first receiver track,

[0028] Fig. 9 The signal of the receiver conductor track of the second receiver track is shown. DETAILED DESCRIPTION

[0029] according to Figure 1 The angle measuring device of the exemplary embodiment presented here has a scanning element 1 for detecting the angular position of a scale element 2. The scale element 2 is arranged rotatably relative to the scanning element 1 about an axis A. Such an angle measuring device can be used, for example, in a drive device, wherein the scale element 2 is then connected, for example, to a drive shaft of a motor in a rotationally fixed manner.

[0030] exist Figure 2 , the scale element 2 is shown in a top view. The scale element 2 has a ring or annular shape. The scale element 2 comprises a substrate 2.3, which is made of epoxy resin in the illustrated embodiment, and on which two graduation tracks 2.1, 2.2 are arranged. The graduation tracks 2.1, 2.2 are annularly constructed and are arranged on the substrate 2.3 concentrically with different radii about the axis A or about the scale center M2 located on the axis A, so that the first graduation track 2.1 extends along a first graduation circle line and the second graduation track 2.2 extends along a second graduation circle line. The graduation tracks 2.1, 2.2 comprise a graduation structure, which respectively comprises a periodic sequence of conductive graduation areas 2.11, 2.21 and non-conductive graduation areas 2.12, 2.22 alternately arranged along the circumferential direction x, wherein the conductive graduation areas 2.11, 2.21 are respectively composed of layers composed of conductive materials. In the example shown, copper is applied to substrate 2.3 as material for electrically conductive graduated areas 2.11, 2.21. In contrast, substrate 2.3 is not coated in non-conductive graduated areas 2.12, 2.22. Figure 1 On the contrary, Figure 2 Conductive graduation areas 2.11, 2.21 are shown filled in black.

[0031] By means of the arrangement with two graduation tracks 2.1, 2.2 respectively, the angular position of the scale element 2 can be determined absolutely. The outer first graduation track 2.1 of the scale element 2 has a greater number of corresponding graduation areas 2.11, 2.12 along the circumferential direction x, so that a greater resolution can be achieved with respect to the measurement of the angular position by means of these graduation areas. In the embodiment presented, the first (outer) graduation track 2.1 has a number of 32 corresponding graduation areas 2.11, 2.12 along the circumferential direction x. The first graduation track 2.1 therefore has a first period length λ1 of 360° / 32=11.25°.

[0032] In contrast, second (inner) graduated track 2.2 has only 15 corresponding graduated regions 2.21, 2.22, so that second graduated track 2.2 has a second period length λ2 of 360° / 15=24°.

[0033] In this case, the period lengths λ1 , λ2 are specified in degrees and relate to the center angle about the axis A or about the scale center M2 .

[0034] Scanning element 1 is designed as a printed circuit board having a plurality of layers and as an electronic component 1 . 5 mounted on scanning element 1 .

[0035] As in Figure 3 As shown in FIG. 1 , the scanning element 1 has the shape of a ring. In the embodiment presented, the electronic component 1.5 is mounted only on one side of the circuit board, namely on the side facing away from the scale element 2. However, alternatively or additionally, both sides of the circuit board can also be equipped with the electronic component 1.5.

[0036] In order to determine the angle information, according to Figure 3 Scanning element 1 has a first receiver track 1.1 and a second receiver track 1.2. Receiver tracks 1.1, 1.2 each have an annular shape, wherein for both receiver tracks 1.1, 1.2 it is true that their center point M1 lies on axis A. Receiver tracks 1.1, 1.2 are therefore arranged concentrically in a first approximation with respect to center point M1.

[0037] In the exemplary embodiment presented, first receiver track 1.1 comprises first receiver conductor track 1.11, second receiver conductor track 1.12, third receiver conductor track 1.13 and fourth receiver conductor track 1.14. First receiver track 1.1 thus has a first number n1=4 receiver conductor tracks 1.11, 1.12, 1.13, 1.14.

[0038] Receiver conductor tracks 1.11, 1.12, 1.13, 1.14 of first receiver track 1.1 are arranged offset relative to one another in circumferential direction x, receiver conductor tracks 1.11, 1.12, 1.13, 1.14 extending along a first circumferential line K1 having a first radius R1 ( Figure 5 ). Receiver conductor tracks 1.11, 1.12, 1.13, 1.14 of first receiver track 1.1 have a spatially periodic extension which is designed to be approximately sinusoidal or sinusoidal. Furthermore, receiver conductor tracks 1.11, 1.12, 1.13, 1.14 of first receiver track 1.1 have a constant first period length λ1=11.25° in their course, as can also be seen in first graduated track 2.1 ( Figure 5). The first period length λ1 therefore extends around the midpoint M1 at a central angle of 11.25°.

[0039] exist Figure 5 , only the first receiver conductor track 1.11 and the second receiver conductor track 1.12 are shown. The third receiver conductor track 1.13 and the fourth receiver conductor track 1.14 arranged therebetween are hidden for the sake of clarity. The following explanation will be made with the aid of this illustration of the first receiver conductor track 1.11 and the second receiver conductor track 1.12, wherein these also apply to the third and fourth receiver conductor tracks 1.13, 1.14 which are phase-shifted and respectively associated with each other. In the proposed exemplary embodiment, the first receiver conductor track 1.11 and the second receiver conductor track 1.12 are arranged offset relative to each other along the circumferential direction x by a first angular offset φ1, which corresponds to 1 / 4 of the complete first period length λ1. Therefore, within the first receiver track 1.1, directly adjacent receiver conductor tracks 1.11, 1.12, 1.13, 1.14 are arranged offset along the circumferential direction x by half of the first angular offset φ1.

[0040] φ1=1 / 4·λ1 applies, so that the first angular offset φ1 in the illustrated embodiment is 1 / 4·11.25°=2.81°.

[0041] The second receiver track 1.2 is based on Figure 4 The proposed embodiment of the receiver track 1.2 comprises a fifth receiver conductor track 1.21, a sixth receiver conductor track 1.22, a seventh receiver conductor track 1.23, an eighth receiver conductor track 1.24, a ninth receiver conductor track 1.25, a tenth receiver conductor track 1.26, an eleventh receiver conductor track 1.27 and a twelfth receiver conductor track 1.28. Thus, the second receiver track 1.2 has a second number n2=8 receiver conductor tracks 1.21 to 1.28. The receiver conductor tracks 1.21 to 1.28 of the second receiver track 1.2 are also arranged offset relative to one another in the circumferential direction x. They are arranged along the second circumferential line K2 ( Figure 5 ), which has a second radius R2. Receiver conductor tracks 1.21 to 1.28 of second receiver track 1.2 have a constant second period length λ2 in their course, wherein the course deviates from an ideal sinusoidal shape. Receiver conductor tracks 1.21 to 1.28 of second receiver track 1.2 also have a periodic course. In the exemplary embodiment presented, second period length λ2=360° / 15=24°.

[0042] In this case, the second period length λ2 is therefore greater than the first period length λ1 .

[0043] λ2>λ1

[0044] Receiver conductor tracks 1.21 to 1.28 of second receiver track 1.2 extend along a second circumferential line K2 which has a second radius R2, wherein second radius R2 is smaller than first radius R1, so that:

[0045] R2 <R1

[0046] The two circular lines K1 , K2 have the same midpoint M1 .

[0047] Furthermore, first number n1=4 of receiver conductor tracks 1.11, 1.12, 1.13, 1.14 of first receiver track 1.1 is smaller than second number n2=8 of receiver conductor tracks 1.21 to 1.28 of second receiver track 1.2:

[0048] n1 <n2

[0049] In the exemplary embodiment presented, it therefore also applies that the second number n2 is twice as large as the first number n1 .

[0050] n2=2·n1

[0051] exist Figure 5 , only the fifth receiver conductor track 1.21 and the sixth receiver conductor track 1.22 are shown for the second receiver track 1.2. The following explanation is made with reference to this illustration of the fifth receiver conductor track 1.21 and the sixth receiver conductor track 1.22, wherein this also applies to the correspondingly mutually associated phase-shifted receiver conductor tracks 1.23, 1.24, 1.25, 1.26, 1.27, 1.28. In the proposed exemplary embodiment, adjacent receiver conductor tracks 1.21 to 1.28 in the second receiver track 1.2 are arranged offset relative to one another along the circumferential direction x at a second angular offset φ2, which corresponds to 1 / 16 of the complete second period length λ2. (φ2=24° / 16=1.5°). In the second receiver track 1.2, two adjacent receiver conductor tracks 1.21 to 1.28 are respectively connected in series with one another. In particular, fifth and sixth receiver conductor tracks 1.21, 1.22 are connected in series with one another, as are seventh and eighth receiver conductor tracks 1.23, 1.24, ninth and tenth receiver conductor tracks 1.25, 1.26, and eleventh and twelfth receiver conductor tracks 1.27, 1.28.

[0052] Furthermore, scanning element 1 comprises a first exciter track 1.3 and a second exciter track 1.4. In the exemplary embodiment presented, exciter tracks 1.3, 1.4 comprise a plurality of exciter lines, but can also each be designed as only one exciter line. First receiver track 1.1 extends radially inside first exciter track 1.3 and radially outside second exciter track 1.4. Furthermore, second exciter track 1.4 extends radially outside second receiver track 1.2. Both exciter tracks 1.3, 1.4 and receiver tracks 1.1, 1.2 extend in a circumferential direction x.

[0053] Receiver conductor tracks 1.11, 1.12, 1.13, 1.14 of first receiver track 1.1 and receiver conductor tracks 1.21 to 1.28 of second receiver track 1.2 extend from through-hole V( Figure 6 and Figure 7 ) are connected to different layers of the circuit board, thereby avoiding undesired short circuits at the intersections. Although to be precise, each conductor path in the receiver conductor tracks 1.11 to 1.14; 1.21 to 1.28 is composed of a plurality of conductor parts, which are respectively distributed on two planes or layers and arranged in rows, such a structure is collectively referred to as receiver conductor tracks 1.11 to 1.14, 1.21 to 1.28.

[0054] exist Figure 6 Schematically shows the extension of first and second receiver conductor tracks 1.11, 1.12, wherein the actually surrounding first and second receiver conductor tracks 1.11, 1.12 are shown stretched for the sake of clarity. Figure 6 In the diagram, the first and second receiver conductor tracks 1.11, 1.12, which are stacked one on top of the other, are shortened and shown offset relative to one another in order to more clearly show the respective course of the receiver conductor tracks 1.11, 1.12. Accordingly, the circumferential direction x, i.e. the measuring direction, is shown linearly here. As described above, the first and second receiver conductor tracks 1.11, 1.12 each have a sinusoidal course. In the diagram, the first and second receiver conductor tracks 1.11, 1.12 are shown offset relative to one another in order to more clearly show the respective course of the receiver conductor tracks 1.11, 1.12. Figure 6 The ends shown in are electrically connected to each other at point U.

[0055] exist Figure 7 2 shows schematically and linearly separated fifth and sixth receiver conductor tracks 1.21, 1.22 as well as seventh and eighth receiver conductor tracks 1.23, 1.24. Figure 7The simplified illustration of is to be understood as follows: the left and right ends of the receiver conductor tracks 1.21, 1.22, 1.23, 1.24 meet again, so that there is also a closed circuit there, in which the fifth and sixth receiver conductor tracks 1.21, 1.22 are connected in series with each other, and the seventh and eighth receiver conductor tracks 1.23, 1.24 are also connected in series with each other. Figure 7 The ends U shown in FIG. are electrically connected to each other at point U. Figure 6 , between points U, receiver conductor tracks 1.21, 1.22, 1.23, 1.24 extend one above the other in two planes and, more precisely, from the upper left to the lower right or from the upper right to the lower left. Figure 7 In the illustrated form of the drawings, the receiver conductor tracks 1.21 to 1.28 have a largely straight extension, so that they each surround a rhombus-shaped surface. This geometrical construction makes it possible to achieve a relatively compact or narrow arrangement of the receiver conductor tracks 1.21 to 1.28 on the substrate 1.3. If the actually arranged receiver conductor tracks 1.21 to 1.28 are correspondingly curved, the receiver conductor tracks 1.21 to 1.28 of the second receiver track 1.2 have a curved extension with a relatively large radius between the reversal points. For space reasons, the through-holes V are arranged outwardly here, wherein the through-holes V located radially inside are each arranged offset in the radial direction (see also Figures 3 to 5 ).

[0056] In the assembled state, scanning element 1 and scale element 2 are arranged opposite each other with an axial spacing or air gap, so that in the event of a relative rotation between scale element 2 and scanning element 1, a signal which is dependent on the corresponding angular position can be generated in receiver conductor tracks 1.11 to 1.14, 1.21 to 1.28 by inductive effects. The formation of the corresponding signals presupposes that exciter tracks 1.3, 1.4 generate electromagnetic excitation fields which alternate in time in the region of the correspondingly scanned graduation structures. In the illustrated embodiment, exciter tracks 1.3, 1.4 are designed as a plurality of plane-parallel individual conductor tracks through which current flows.

[0057] If exciter tracks 1.3, 1.4 are energized, an electromagnetic field oriented in a tubular or cylindrical manner is formed around exciter tracks 1.3, 1.4. The field lines of the generated electromagnetic field extend around exciter tracks 1.3, 1.4, wherein the direction of the field lines depends on the direction of the current in exciter tracks 1.3, 1.4 in a known manner. Eddy currents are induced in the region of the electrically conductive graduation regions 2.11, 2.21, so that a modulation of the field is achieved in each case in a manner dependent on the angular position. Accordingly, the relative angular position can be measured by receiver tracks 1.1, 1.2 in each case.

[0058] In particular, at the contact point C (see for example Figure 6 ) can detect a first signal S1.11 generated or received by first receiver conductor track 1.11 and a second signal S1.12 generated or received by second receiver conductor track 1.12. The course or envelope of first signal S1.11 and second signal S1.12 is Figure 8 1 and 2 are shown in FIG. 1 according to the corresponding angular position between scanning element 1 and scale element 2. First signal S1.11 and second signal S1.12 have a first phase offset PH1 relative to one another, which in the illustrated embodiment is π / 2, wherein a complete period of first signal S1.11 and second signal S1.12 is 2π by definition. First receiver conductor track 1.11 and second receiver conductor track 1.12 therefore provide 0° and 90° signals.

[0059] The period of first signal S1.11 and second signal S1.12 results from the geometrical design of first receiver conductor track 1.11 and second receiver conductor track 1.12 in combination with the geometrical shape of first graduated track 2.1. Figure 5 have a geometric first period length λ1 and are arranged relative to each other in the circumferential direction x at an angle offset φ1 (=1 / 4·λ1). Accordingly, the first signal S1.11 and the second signal S1.12 have a period corresponding to the first period length λ1. In addition, the value of the first phase offset PH1 can also be expressed as 1 / 4·λ1:

[0060] PH1=1 / 4·λ1.

[0061] Third receiver conductor track 1.13 and fourth receiver conductor track 1.14 are arranged offset relative to first receiver conductor track 1.11 and second receiver conductor track 1.12, so that third receiver conductor track 1.13 provides a third signal which is phase-shifted by π / 4 relative to first signal S1.11 of first receiver conductor track 1.11. Similarly, the fourth signal of fourth receiver conductor track 1.14 is phase-shifted by π / 4 relative to second signal S1.12. The third and fourth signals are used to obtain redundant position values, in particular for safety-related applications.

[0062] The fifth receiver conductor track and the sixth receiver conductor track 1.21, 1.22 are connected according to Fig. 9 Accordingly, a fifth signal S1.21 and a sixth signal S1.22 are generated in turn. The fifth signal S1.21 and the sixth signal S1.22 have a phase shift ph of π / 8 (22.5°). Since the fifth and sixth receiver conductor tracks 1.21, 1.22 are connected in series with one another, the first total signal SU1 is generated by them.

[0063] Similarly, a seventh signal S1.23 and an eighth signal S1.24 are generated separately by the seventh receiver conductor track 1.23 and by the eighth receiver conductor track 1.24. The seventh and eighth signals S1.23, S1.24 have the same phase shift ph of π / 8 as the fifth signal S1.21 and the sixth signal S1.22. The seventh and eighth receiver conductor tracks 1.23, 1.24 are also connected in series with each other. As a result, a second total signal SU2 is generated by the seventh and eighth receiver conductor tracks 1.23, 1.24.

[0064] The values ​​of the phase offset ph of π / 8 and the second phase offset PH2 of π / 2 are understood in the context of the definitions, according to which the full period of the fifth, sixth, seventh and eighth signals S1.21, S1.22, S1.23, S1.24 and the second total signal SU2 is 2π.

[0065] The fifth, sixth, seventh and eighth signals S1.21, S1.22, S1.23, S1.24 and the first total signal SU1 and the second total signal SU2 each have a period of the same size with a second period length λ2. This period is generated by the geometric design of the fifth receiver conductor track 1.21 and the sixth receiver conductor track 1.22 in combination with the geometry of the second graduated track 2.2. These receiver conductor tracks 1.21, 1.22 are arranged according to Figure 5The fifth signal S1.21 and the sixth signal S1.22 have a geometric second period length λ2 and are arranged relative to each other at a second angle offset φ2 (=1 / 16·λ2) in the circumferential direction x. Therefore, the fifth signal S1.21 and the sixth signal S1.22 have a period corresponding to the second period length λ2. In this regard, the magnitude of the phase offset ph between the fifth signal S1.21 and the sixth signal S1.22 or between the seventh signal S1.23 and the eighth signal S1.24 can also be described as 1 / 16·λ2:

[0066] ph=1 / 16·λ2

[0067] Furthermore, the first total signal SU1 and the second total signal SU2 have a second phase offset PH2 with respect to each other, which in the exemplary embodiment described corresponds to π / 2, wherein the full period of the first total signal SU1 and the second total signal SU2 is 2π by definition. The second phase offset PH2 is therefore 1 / 4·λ2, i.e.:

[0068] PH2=1 / 4·λ2.

[0069] Therefore, the first total signal SU1 and the second total signal SU2 can be used as 0° and 90° signals. Another pair of total signals (45° and 135° signals) shifted by 90° to each other can be formed via the ninth receiver conductor track to the twelfth receiver conductor track 1.25 to 1.28, so that redundant position value detection is also performed here.

[0070] The scanning element 1 has an electronic circuit with electronic components 1.5, which are electrically connected to one another. The electronic circuit can also include an ASIC module, for example. The signals generated by the receiver tracks 1.1, 1.2 are further processed by means of some of the electronic components 1.5 forming an evaluation circuit. In particular, in the present configuration with two graduation tracks 2.1, 2.2 and two receiver tracks 1.1, 1.2, the absolute position can be calculated by means of an evaluation ASIC. This electronic circuit of the scanning element 1 works not only as an evaluation element, but also as an excitation control element, under the control of which an excitation current is generated or produced, which then flows through the exciter tracks 1.3, 1.4. Therefore, the exciter tracks 1.3, 1.4 are energized by the same excitation control element.

[0071] First receiver track 1.1 is surrounded radially on the outside by first exciter track 1.3 and at the same time radially on the inside by second exciter track 1.4. Second receiver track 1.2, in contrast, is surrounded only on one side by second exciter track 1.4. By applying the excitation field on one side of second receiver track 1.2, a very space-saving configuration of scanning element 1 can be achieved. In this case, sufficiently large first signal S1.11 and second signal S1.12 can be generated by a special design of receiver tracks 1.1, 1.2, in particular second receiver track 1.2. Furthermore, the one-sided application of the excitation field involves second receiver tracks 1.2, whose second period length λ2 is greater than the first period length λ1 of first receiver track 1.1, so that the one-sided application of the excitation field involves those (second) receiver tracks 1.2 with a coarser resolution.

Claims

1. An inductive angle measuring device, comprising a scanning element (1) and a scale element (2) rotatable relative to the scanning element (1), wherein: The scale element (2) has a first scale structure (2.11, 2.12) and a second graduation track (2.2) with a periodically arranged second graduation structure (2.21, 2.22), The scanning element (1) has an exciter track (1.3, 1.4) and a first receiver track (1.1) and a second receiver track (1.2), wherein: The first receiver track (1.1) comprises a first receiver conductor track (1.11) and a second receiver conductor track (1.12), wherein the first receiver conductor track and the second receiver conductor track (1.11, 1.12) extend periodically along a first circumferential line (K1) having a first radius (R1), wherein the first receiver conductor track and the second receiver conductor track (1.11, 1.12) are arranged offset to one another in a circumferential direction (x), so that the first receiver conductor track (1.11) can generate a first signal (S1.11) and the second receiver conductor track (1.12) can generate a second signal (S1.12), wherein the first signal (S1.11) and the second signal (S1.12) have a first phase offset (PH1) relative to one another, The second receiver track (1.2) comprises a fifth receiver conductor track (1.21), a sixth receiver conductor track (1.22), a seventh receiver conductor track (1.23) and an eighth receiver conductor track (1.24), wherein the fifth receiver conductor track, the sixth receiver conductor track, the seventh receiver conductor track and the eighth receiver conductor track (1.21, 1.22, 1.23, 1.24) respectively extend periodically along a second circumferential line (K2) having a second radius (R2) and are respectively arranged offset relative to one another in a circumferential direction (x), wherein: The fifth receiver conductor track and the sixth receiver conductor track (1.21, 1.22) are connected in series with one another so that the fifth receiver conductor track and the sixth receiver conductor track (1.21, 1.22) can generate a first total signal (SU1), and the seventh receiver conductor track and the eighth receiver conductor track (1.23, 1.24) are likewise connected in series with one another so that the seventh receiver conductor track and the eighth receiver conductor track (1.23, 1.24) can generate a second total signal (SU2), wherein: The first total signal (SU1) and the second total signal (SU2) have a second phase offset (PH2) relative to one another.

2. The inductive angle measuring device according to claim 1, wherein: The first receiver conductor track and the second receiver conductor track (1.11, 1.12) extend periodically with a constant first period length (λ1).

3. The inductive angle measuring device according to claim 1 or 2, wherein: The fifth receiver conductor track, the sixth receiver conductor track, the seventh receiver conductor track and the eighth receiver conductor track (1.21, 1.22, 1.23, 1.24) extend periodically with a constant second period length (λ2).

4. The inductive angle measuring device according to claims 2 and 3, wherein: The second period length (λ2) is greater than the first period length (λ1).

5. The inductive angle measuring device according to any one of the preceding claims, wherein: The first receiver conductor track and the second receiver conductor track (1.11, 1.12) extend periodically with a constant first period length (λ1), wherein the first phase offset (PH1) is one quarter of the first period length (λ1).

6. The inductive angle measuring device according to any one of the preceding claims, wherein: The fifth receiver conductor track, the sixth receiver conductor track, the seventh receiver conductor track and the eighth receiver conductor track (1.21, 1.22, 1.23, 1.24) extend periodically with a constant second period length (λ2), wherein the second phase offset (PH2) is one quarter of the second period length (λ2).

7. The inductive angle measuring device according to any one of the preceding claims, wherein: The first receiver track (1.1) has a first number n1 of receiver conductor tracks (1.11, 1.12, 1.13, 1.14), and the second receiver track (1.2) has a second number n2 of receiver conductor tracks (1.21 to 1.28), wherein n1 is smaller than n2.

8. The inductive angle measuring device according to claim 7, wherein: The second number n2 is at least twice as large as the first number n1, ie n2 ≥ 2·n1.

9. The inductive angle measuring device according to any one of the preceding claims, wherein: The second radius (R2) is smaller than the first radius (R1).

10. The inductive angle measuring device according to any one of the preceding claims, wherein: The scanning element (1) comprises a first exciter track (1.3) and a second exciter track (1.4), wherein the first receiver track (1.1) is surrounded radially on the outside by the first exciter track (1.3) and radially on the inside by the second exciter track (1.4), while the second receiver track (1.2) is surrounded only on one side by the second exciter track (1.4).

11. The inductive angle measuring device according to any one of the preceding claims, wherein: The fifth receiver conductor track and the sixth receiver conductor track (1.21, 1.22) extend periodically with a constant second period length (λ2) and are arranged offset relative to each other along the circumferential direction (x) with an angular offset (φ2), wherein the angular offset (φ2) is at most 1 / 16 of the second period length λ2, so that: φ2≤1 / 16·λ2 applies.

12. The inductive angle measuring device according to any one of the preceding claims, wherein: The seventh receiver conductor track and the eighth receiver conductor track (1.23, 1.24) extend periodically with a constant second period length (λ2) and are arranged offset relative to each other along the circumferential direction (x) with an angular offset (φ2), wherein the angular offset (φ2) is at most 1 / 16 of the second period length λ2, so that: φ2≤1 / 16·λ2 applies.

13. The inductive angle measuring device according to any one of the preceding claims, wherein: The scanning element (1) is designed as a circuit board, and the exciter tracks (1.3, 1.4), the first receiver tracks (1.1) and the second receiver tracks (1.2) extend in less than four conductive layers.

14. The inductive angle measuring device according to any one of the preceding claims, wherein: The first receiver track (1.1) and / or the second receiver track (1.2) extend over the entire circumference.

15. The inductive angle measuring device according to any one of the preceding claims, wherein: The scanning element (1) is designed as a circuit board, and the exciter tracks (1.3, 1.4), the first receiver tracks (1.1) and the second receiver tracks (1.2) extend in exactly two conductive layers.

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