Inductive position measuring device and method for operating an inductive position measuring device

Abstract

An inductive position measuring device (1) comprising a first assembly (10) with a first interaction surface (11) and a second assembly (20) with a second interaction surface (21). The two assemblies (10, 20) are arranged opposite each other in a third measuring direction (z) and are movable relative to each other. The first assembly (10) comprises several first field interaction means (10.X1-10.X2'', 10.Y1-10.Y2'') which are arranged parallel to the first interaction surface (11). The second assembly (20) comprises several second field interaction means (20.1 to 20.n) which are arranged distributed over the area of ​​the second interaction surface (21). The inductive position measuring device (1) is characterized in that at least one first field interaction means (10.X1-10.X2'') is arranged along a first measuring direction (x) and at least one further first field interaction means (10.Y1-10.Y2'') is arranged along a second measuring direction (y), and that the first field interaction means (10.X1-10.X2'', 10.Y1-10.Y2'') each comprise at least one excitation means (10.1, 10.2) and at least one receiving means (10.21, 10.22; 10.23-10.26).

Description

AREA OF TECHNOLOGY

[0001] The invention relates to an inductive position measuring device according to the preamble of claim 1 and a method for operating an inductive position measuring device according to the preamble of claim 11. STATE OF THE ART

[0002] Patent WO 2020 088 869 A1 discloses a motion device with a position determination system, which has a static and a moving assembly. Both assemblies have their own power supply and comprise several circularly arranged coils or capacitor plates that interact electromagnetically with each other.

[0003] A disadvantage of the aforementioned state of the art is that both the moving and stationary assemblies use electrical components that must be connected to active electronics. This means that each assembly requires its own power supply and data connection, resulting in a significantly more complex design, especially for the stationary assembly. SUMMARY OF THE INVENTION

[0004] The invention is based on the objective of providing an inductive position measuring device that enables the position determination of a moving assembly in several degrees of freedom and is simultaneously cost-effective to manufacture.

[0005] This problem is solved according to the invention by the features of claim 1 and claim 11, respectively. Advantageous embodiments and further developments are specified in the respective dependent claims.

[0006] The inductive position measuring device according to the invention comprises a first assembly with a first interaction surface and a second assembly with a second interaction surface. The two assemblies are arranged opposite each other in a third measuring direction and are movable relative to each other. The second interaction surface is larger than the first interaction surface. The first assembly comprises several first field interaction elements arranged parallel to the first interaction surface. The second assembly comprises several second field interaction elements distributed over the area of ​​the second interaction surface. The first and second field interaction elements can be brought into electromagnetic interaction.The inductive position measuring device is characterized in that at least one first field interaction means is arranged along a first measuring direction and at least one second first field interaction means is arranged along a second measuring direction, and that the first field interaction means each comprise at least one generating means for generating an electromagnetic field and at least one receiving means for receiving an electromagnetic field.

[0007] According to an advantageous further development of the invention, the first field interaction means are designed as elongated linear sensors and the first and second measuring directions run perpendicular to each other.

[0008] An elongated linear sensor is defined as a sensor designed to generate an electrical signal depending on its relative position with respect to one of the measuring directions and its distance to the second assembly. The linear sensor is designed such that its dimension along the measuring direction to which it is parallel is larger than its other dimensions.

[0009] In further development, the first field interaction devices include • each a first receiving means and a second receiving means, which have a periodic profile with a constant period length, wherein the receiving means are arranged offset from each other by a quarter of their period length in the first or second measuring direction, and • each an inducing agent which surrounds the two receiving agents, in particular in the form of a square.

[0010] Advantageously, the first assembly comprises four first field interaction means, which are arranged in the first interaction surface and are each perpendicular to each other.

[0011] If a design with the first four field interaction means is provided, the receiving means of the first four field interaction means are advantageously designed such that their oscillation width corresponds to at least one period length.

[0012] Alternatively, the first assembly comprises eight first field interaction means arranged in the first interaction surface and in pairs parallel to field interaction pairs, with the four field interaction mean pairs then arranged perpendicular to each other.

[0013] The vertical arrangement of the four field interaction means or the four field interaction pairs is such that each field interaction means or field interaction pair runs perpendicular to exactly two adjacent field interaction means or field interaction pairs, i.e., a square arrangement is formed by the field interaction means or field interaction pairs.

[0014] If an embodiment with eight field interaction elements or four field interaction pairs is provided, the first receiving elements of at least one of the field interaction pairs are advantageously identical and connected in series. Additionally, the second receiving elements of at least one of the field interaction pairs are identical and connected in series. The amplitude of at least one of the receiving elements is less than half the period, and the distance between the two first receiving elements or the two second receiving elements within at least one field interaction pair is half the period.

[0015] This refers to the distance within a field interaction pair that is formed between the receiving means of one first field interaction means and the receiving means of the other first field interaction means with respect to the virtual zero crossings.

[0016] Preferably, in each of the four field interaction pairs, the first receiving means are identical and the first receiving means within a field interaction pair are connected in series. Likewise, preferably in each of the four field interaction pairs, the second receiving means are identical and the first receiving means within a field interaction pair are connected in series.

[0017] In a further development, it is planned that the second assembly is not connected to an active power supply unit and data processing unit.

[0018] Thus, only the first module is connected to an active power supply and data processing system.

[0019] The second field interaction means are advantageous • rectangular in shape, especially as square surfaces, and • of equal size and uniformly distributed in a grid pattern on the second interaction surface.

[0020] Advantageously, the second field interaction media are produced using a planar technology, in particular by a thick-film technique and additionally or alternatively by a thin-film technique.

[0021] The inventive method for operating an inductive position measuring device is characterized in that a predetermined excitation signal is sent to the second assembly using at least one first field interaction means, and a received signal present at at least one first field interaction means is then measured separately. By corresponding signal evaluation of at least one received signal, linear position information and, additionally or alternatively, distance information of the at least one first field interaction means with respect to the second assembly are determined.

[0022] Preferably, the predetermined excitation signal is modulated by at least one second field interaction means before it is measured as a received signal by at least one receiving means.

[0023] Preferably, the excitation signal is generated and the reception signal is received by the excitation medium and the reception medium, respectively, which belong to the same field interaction pair and, in particular, to the same first field interaction medium.

[0024] Advantageously, the modulation is carried out depending on the position of at least one second field interaction medium on the second interaction surface.

[0025] Preferably, the inductive position measuring device determines the relative position of the first and second assemblies in at least four degrees of freedom, for example in six degrees of freedom.

[0026] The six degrees of freedom are preferably six spatial degrees of freedom, for example three Cartesian spatial coordinates and three Eulerian angles.

[0027] Advantageously, at least a first quality parameter is derived or determined from the position information and, additionally or alternatively, from the distance information of the first field interaction means, which determine position information or distance information with respect to an identical measurement direction.

[0028] Furthermore, it is planned that at least one rotation information about an axis oriented in one of the measurement directions will be determined from the position information and additionally or alternatively the distance information of at least two first field interaction means or two field interaction pairs.

[0029] It is advantageous to derive or determine at least a second quality parameter from the at least one piece of rotation information.

[0030] In a further development, depending on a first quality parameter and additionally or alternatively depending on a second quality parameter, an error signal is output and an optimization procedure is additionally or alternatively carried out.

[0031] An error signal can be output or an optimization procedure initiated, for example, when a predefined limit value is exceeded.

[0032] The invention is further explained below with regard to other features and advantages by means of a description of exemplary embodiments and with reference to the accompanying schematic drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] It shows: Fig. 1 a perspective view of an inductive position measuring device comprising a first assembly and a second assembly; Fig. 2 a top view of a second assembly; Fig. 3 a top view of a first embodiment of a first field interaction means; Fig. 4 a top view of a second embodiment of a first field interaction means; Fig. 5 a view of a first interaction surface of a first assembly; Fig. 6a, Fig. 6b a schematic representation of an inductive position measuring device in top view, showing a relative rotation of a first assembly about the coordinate axis of the third measuring direction; Fig. 7 a sectional view through an inductive position measuring device with schematically visualized excitation and reception signals. DESCRIPTION OF THE EXECUTION FORMS

[0034] The inductive position measuring device 1 of the embodiment presented below has, according to the Fig. Figure 1 shows a first assembly 10 and a second assembly 20, which are opposite each other in a third measuring direction z and can be moved relative to each other. The first assembly 10 and the second assembly 20 are spaced apart from each other, so that an air gap is formed between the two assemblies 10 and 20.

[0035] The first assembly 10 comprises a first interaction surface 11 with several first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2", 10.Y1', 10.Y1'', 10.Y2', 10.Y2'', wherein the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1", 10.Y2', 10.Y2'' are arranged parallel to the first interaction surface 11 and planar within it. The first assembly 10 is supplied with electrical energy to generate at least one excitation signal S1 and to receive at least one receive signal S2. This can be done, for example, via a cable or wirelessly. The energy source can be, for example, a battery inside the first assembly 10 or be located outside the first assembly 10.

[0036] The second assembly 20 comprises a second interaction surface 21 with several second field interaction elements 20.1 to 20.n. The second field interaction elements 20.1 to 20.n are arranged on or planar within the second interaction surface 21 and distributed over its surface. The second assembly 20 does not independently generate its own magnetic field and is not actively supplied with electrical energy via cables or the like, as the second assembly 20 interacts purely passively with the first assembly 10.

[0037] The second interaction surface 21 of the second assembly 20 is generally larger than the first interaction surface 11 of the first assembly 10, so that even when the first assembly 10 is positioned in the edge region of the second assembly 20 there is always sufficient overlap between the two assemblies 10, 20.

[0038] The two interaction surfaces 11, 21 are arranged opposite each other and spaced apart such that position determination by electromagnetic interaction between the first and second field interaction means 10.X1', 10.X1'', 10.X2', 10.X2", 10.Y1', 10.Y1'', 10.Y2', 10.Y2" or 20.1 to 20.n is possible. This is particularly the case when the first and second field interaction means 10.X1', 10.X1", 10.X2', 10.X2", 10.Y1', 10.Y1", 10.Y2', 10.Y2" or 20.1 to 20.n overlap at least partially in the top view considered in the third measurement direction z.

[0039] During operation of the inductive position measuring device 1, the position and orientation of the assemblies 10, 20 relative to each other can change in the three measuring directions x, y, z. Advantageously, the three measuring directions x, y, z are orthogonal to each other. Through the electromagnetic interaction of the first field interaction means 10.X1', 10.X1", 10.X2', 10.X2", 10.Y1', 10.Y1'', 10.Y2', 10.Y2'' with the second field interaction means 20.1 to 20.n, the current position and orientation in six degrees of freedom are determined and evaluated by the inductive position measuring device 1. An evaluation unit for evaluating the position and orientation of the first assembly 10 can be provided inside or outside the first assembly 10. Data transmission can be carried out, for example, via cable or, alternatively, wirelessly.

[0040] Preferably, one of the assemblies is stationary and immobile, while the other assembly is freely movable. In particular, if the second interaction surface 21 of the second assembly 20 is many times larger than the first interaction surface 11 of the first assembly 10, a stationary and immobile arrangement of the second assembly 20 is advantageous. Alternatively, the first assembly 10 can be stationary and the second assembly 20 can be moved relative to the first assembly 10. This is advantageous, for example, if it is not possible to supply the moving assembly with electrical energy.

[0041] Fig. Figure 2 shows a preferred embodiment of the second interaction surface 21 of the second assembly 20. The second interaction surface 21 can have virtually any topography or be arbitrarily curved, and is preferably planar.

[0042] The second interaction surface 21 is preferably the surface of a printed circuit board (PCB) produced by a thin-film process and, additionally or alternatively, by a thick-film process. The PCB comprises an electrically insulating base material 19, for example, a fiber-reinforced epoxy resin. An electrically conductive layer, in particular made of copper, is applied to the base material 19 of the PCB, which is structured such that several second interaction elements 20.1 to 20.n are formed.

[0043] Alternatively, the individual second field interaction elements 20.1 to 20.n and the second interaction surface 21 can also be formed from a substrate. In particular, this can be a metal substrate in which the individual second field interaction elements 20.1 to 20.n are formed as raised areas, with no metal substrate present between the individual second field interaction elements 20.1 to 20.n. The areas between the individual second field interaction elements 20.1 to 20.n can either be formed as a void or air gap, or, for example, filled with an epoxy resin, so that a flat surface is formed.

[0044] The second field interaction means 20.1 to 20.n are arranged in a square grid across the second interaction surface 21 and are spaced at defined intervals. The columns and rows of the second field interaction means 20.1 to 20.n in the grid are arranged along the orthogonal first and second measurement directions x, y. All second field interaction means 20.1 to 20.n are identically dimensioned, specifically in the form of squares. However, other shapes are also conceivable, for example, circles, rectangles, spirals, etc.

[0045] The grid can be, as in Fig. Figure 2 shows that the second interaction surface 21 can be completely filled with second field interaction media 20.1 to 20.n, such that the second field interaction media 20.1 to 20.n are uniformly distributed in a grid-like pattern. Alternatively, the second field interaction media 20.1 to 20.n can also be unevenly distributed over the second interaction surface 21, such that the grid includes individual locations or areas without second field interaction media 20.1 to 20.n.

[0046] Fig. Figure 3 shows a first embodiment of the first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2. The illustrated first field interaction means 10.X1 is an elongated linear sensor comprising a planar excitation means 10.1 for generating electromagnetic fields and two planar receiving means 10.21, 10.22 for receiving electromagnetic fields.

[0047] The first receiving element 10.21 is designed as a receiver conductor track and consists of several conductor track segments. The basic shape of the first receiving element 10.21 is structurally similar to a sinusoidal waveform, although the magnitude of the individual conductor track amplitudes is not necessarily constant. Two adjacent conductor track amplitudes of the basic shape—consisting of a positive and a negative conductor track amplitude—have a period T1 and a amplitude SB1.

[0048] The first receiving device 10.21 can be divided into an incoming and a return section. The incoming section resembles the graph of the function f(x) = a · sin(x) with a ∈ ℝ in its basic shape. + The return section is similar in its basic shape to the graph of the function g(x) = -a · sin(x) with a ∈ ℝ +. That is, the return section of the first receiving device 10.21 corresponds approximately to the forward section reflected across a line of symmetry.

[0049] The second receiver 10.22, like the first receiver 10.21, is configured as a receiver conductor, but is offset from the first receiver 10.21 by one-quarter of the period length T1 (offset V1). The offset V1 is specifically along the first measurement direction x or along the second measurement direction y. Due to the offset arrangement of the two receivers 10.21 and 10.22, correspondingly phase-shifted signals can be generated. The two receivers 10.21 and 10.22 are electrically connected such that they provide a 0° signal and a 90° signal.

[0050] The two receiving means 10.21 and 10.22 differ in their length. For example, the first receiving means 10.21 has a length of three periods, each with a period length of T1, and the second receiving means 10.22 has a length of two and a half periods, each with a period length of T1.

[0051] The amplitude SB1 of the receiving instruments 10.21 and 10.22 is defined as the magnitude of the displacement between the minimum and maximum values ​​within a period T1. It is perpendicular to the direction of the period T1, i.e., perpendicular to the first and second measurement directions x and y, respectively.

[0052] According to the first embodiment of the first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2, the vibration widths SB1 of the first receiving means 10.21 and the vibration widths SB1 of the second receiving means 10.22 are on average the same and correspond at least to the period length T1.

[0053] The in Fig. The 3 receivers shown, 10.21 and 10.22, have oscillation widths SB1 that correspond approximately to 1.5 times the period length T1.

[0054] The two receiving elements 10.21, 10.22 are formed from several conductor track sections in different layers of a carrier substrate. Details of such a multilayer structure of conductor track sections are described in European patent application EP23200280 dated 28.09.2023, to which express reference is made.

[0055] To compensate for pitch tilt, the receiving elements 10.21, 10.22 can have additional loops S, S' at certain points, which are also formed from conductor track segments. For this purpose, the loops S, S' are placed below the conductor track amplitudes at predetermined locations along the basic path. At locations with the additional loops S, S', the conductor track amplitudes of the receiving elements 10.21, 10.22 deviate from the basic path and are shifted outwards by a predetermined amount, i.e., in the direction of the excitation element 10.1. The loops S, S' are shifted slightly inwards with respect to the conductor track amplitudes of the basic path, i.e., in the direction of the virtual zero crossing of the basic path of the receiving elements 10.21, 10.22.In summary, a constructively different conductor track amplitude in combination with a loop results in an identically large amplitude signal as a normal conductor track amplitude without a loop.

[0056] The loops S, S' are part of the receiver conductor track and are preferably arranged on the first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 such that they are arranged in a mirror-symmetrical manner to an axis A - which divides the incoming and return sections into equal parts.

[0057] The loops S of the first receiving device 10.21 can be formed either within the incoming section and additionally or alternatively within the return section of the receiver conductor track.

[0058] The loops S' of the second receiving device 10.22 can also be formed either within the incoming section and additionally or alternatively within the return section of the receiver conductor track.

[0059] The two receiving elements 10.21, 10.22 are enclosed by the excitation element 10.1, i.e., surrounded on all sides. The excitation element 10.1 is designed as an excitation conductor and is structurally in the form of a quadrilateral. In particular, the quadrilateral is at least a rectangle.

[0060] According to a second embodiment of the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'', their arrangement is also possible in field interaction pairs 10.PX1, 10.PX2, 10.PY1, 10.PY2.

[0061] The in Fig. The field interaction pair 10.PX1 shown in Figure 4 comprises the first field interaction means 10.X1' and the second first field interaction means 10.X1''. The two first field interaction means 10.X1', 10.X1'' are designed as elongated linear sensors and together comprise a planar excitation means 10.2 (shown in Figure 4). Fig. 4) or alternatively, a planar excitation device for generating electromagnetic fields (not shown).

[0062] The first field interaction means 10.X1' comprises a planar first receiving means 10.23 and a planar second receiving means 10.24 for receiving electromagnetic fields. The further first field interaction means 10.X' also comprises a planar first receiving means 10.25 and a planar second receiving means 10.26 for receiving electromagnetic fields.

[0063] The first field interaction means 10.X1', 10.X1" are spaced apart from each other, such that an offset V3 is formed between the two first field interaction means 10.X1', 10.X1" with respect to the receiving means 10.23, 10.24 and the receiving means 10.25, 10.26. The offset V3 occurs in particular along the first measuring direction x or along the second measuring direction y. Advantageously, the offset V3 corresponds to half a period length T2.

[0064] An embodiment of the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'' according to the second embodiment and their arrangement into field interaction pairs 10.PX1, 10.PX2, 10.PY1, 10.PY2 ensures that the transverse sensitivity of the inductive measuring device 1 is reduced. In particular, the transverse sensitivity perpendicular to the measuring direction x or to the measuring direction y is reduced.

[0065] The first receiving elements 10.23, 10.25 are configured as receiver conductors and consist of several conductor segments. The basic waveform of the first receiving elements 10.23, 10.25 resembles a sinusoidal waveform, although the magnitude of the individual conductor amplitudes is not necessarily constant due to the design. Two adjacent conductor amplitudes of the basic waveform—consisting of a positive and a negative conductor amplitude—have a period T2 and a amplitude SB2.

[0066] The first receiving instruments 10.23 and 10.25 can each be subdivided into an incoming and a return section. The basic shape of an incoming section resembles the graph of the function f(x) = a · sin(x) with a ∈ ℝ. + A return section is similar in its basic shape to the graph of the function g(x) = -a · sin(x) with a ∈ ℝ +. That is, a return section of the first receiving means 10.23, 10.25 corresponds approximately to a forward section reflected across a line of symmetry.

[0067] The second receiving elements 10.24, 10.26 are configured as receiver conductors, like the first receiving elements 10.23, 10.25, but are offset by one quarter of the period length T2 relative to their respective first receiving elements 10.23, 10.25 (offset V2). The offset V2 is specifically along the first measuring direction x or along the second measuring direction y. Due to the offset arrangement of the two receiving elements 10.23, 10.25 or the two receiving elements 10.24, 10.26, correspondingly phase-shifted signals can be generated. The two receiving elements 10.24, 10.26 or the two receiving elements 10.24, 10.26 are electrically connected such that they provide a 0° signal and a 90° signal.

[0068] The two receiving means 10.23 and 10.25 differ in their length. For example, the first receiving means 10.23 has a length of three periods, each with a period length of T2, and the second receiving means 10.25 has a length of two and a half periods, each with a period length of T2.

[0069] In an embodiment of the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'' according to the second embodiment, the first receiving means 10.23 of the first field interaction means 10.X1' is connected in series with the first receiving means 10.25 of the second first field interaction means 10.X1''. Furthermore, the second receiving means 10.24 of the first field interaction means 10.X1' is connected in series with the second receiving means 10.26 of the second first field interaction means 10.X''. This series connection results in a 0° signal and a 90° signal, respectively, with increased signal amplitudes.

[0070] The amplitude SB2 for receivers 10.23, 10.25, 10.24, 10.26 is defined as the amplitude of the displacement between the minimum and maximum values ​​within a period T2. It is perpendicular to the direction of the period T2, i.e., perpendicular to the first and second measurement directions x and y, respectively.

[0071] According to the second embodiment of the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'', the oscillation widths SB2 of a first receiving means 10.23, 10.25 and the oscillation width SB2 of an associated second receiving means 10.24, 10.26 are on average the same and correspond to at most half the period length T2.

[0072] The in Fig. The 3 receiving devices shown, 10.23, 10.25, 10.24, 10.26, have oscillation widths SB2 that correspond approximately to one third of the period length T2.

[0073] The first and second receiving means 10.23, 10.25, 10.24, 10.26 are formed from several conductor track sections in different layers of a substrate, just as in the first embodiment.

[0074] To compensate for pitch misalignments, the receiving elements 10.23, 10.25, 10.24, and 10.26 can also have additional loops S and S' at certain points, formed from conductor track segments. For this purpose, the loops S and S' are placed below the conductor track amplitudes at predetermined locations along the basic path. At locations with the additional loops S and S', the conductor track amplitudes of the receiving elements 10.21 and 10.22 deviate from the basic path and are shifted outwards by a predetermined amount, i.e., towards the excitation element 10.1. The loops S and S' are shifted slightly inwards relative to the conductor track amplitudes of the basic path, i.e., towards the virtual zero crossing of the basic path of the receiving elements 10.23, 10.25, 10.24, and 10.26.In summary, a constructively different conductor track amplitude with a loop results in an identical amplitude signal as a normal conductor track amplitude without a loop.

[0075] The loops S, S' are part of a receiver conductor track and are preferably arranged on the two first field interaction means 10.X1', 10.X1'' such that they are arranged in a mirror-symmetrical manner to an axis A, which divides a forward or return section into equal parts.

[0076] The loops S of the first receiving means 10.23, 10.25 can be formed either within an incoming section and additionally or alternatively within a return section of the receiver conductor tracks.

[0077] The loops S' of the second receiving means 10.24, 10.26 can also be formed either within an incoming section and additionally or alternatively within a return section of the receiver conductor tracks.

[0078] As previously explained, the receiving means 10.23, 10.25, 10.24, 10.26 are either surrounded by a common excitation means 10.2 or by several separate excitation means, i.e., enclosed on all sides. The excitation means 10.2 is configured as an excitation conductor and is structurally designed in the form of at least a quadrilateral. In particular, the quadrilateral is at least a rectangle.

[0079] For example, the single inducing agent 10.2 can form two rectangles, one rectangle around the receiving agents 10.23, 10.24 and one rectangle around the receiving agents 10.25, 10.26, as shown in Fig. Figure 4 is shown. Alternatively, two inducers can be provided, with one inducer forming a rectangle around the receiving means 10.23, 10.24 and another inducer forming a rectangle around the receiving means 10.25, 10.26.

[0080] The first field interaction means 10.X1, 10.X1', 10.X1'', 10.X2, 10.X2', 10.X2'', 10.Y1, 10.Y1', 10.Y1'', 10.Y2, 10.Y2', 10.Y2'' are formed within the first interaction surface 11 of the first assembly 10. The first interaction surface 11 is the surface of a printed circuit board, which is manufactured using a thin-film process and, additionally or alternatively, a thick-film process. To form the structured first field interaction elements 10.X1, 10.X1', 10.X1'', 10.X2, 10.X2', 10.X2'', 10.Y1, 10.Y1', 10.Y1'', 10.Y2, 10.Y2', 10.Y2'', several separate, superimposed, and electrically conductive layers can be provided, separated from each other by insulating layers. At predefined locations, the so-called vias, an electrical connection exists between the conductor tracks of the different electrically conductive layers.

[0081] As in Fig. As shown in Figure 5, the first two field interaction elements 10.X1, 10.X2, or the two field interaction pairs 10.PX1, 10.PX2, extend parallel to the first measurement direction x and are spaced apart from each other by a distance Dx. The first two field interaction elements 10.Y1, 10.Y2, or the two field interaction pairs 10.PY1, 10.PY2, ​​extend parallel to the second measurement direction y and are also spaced apart from each other by a distance Dy. Advantageously, the arrangement of the first field interaction elements 10.X1, 10.X2, 10.Y1, 10.Y2, or the field interaction pairs 10.PX1, 10.PX2, 10.PY1, 10.PY2, ​​corresponds to a quadrilateral arrangement, in particular in the form of a square (Dx = Dy).

[0082] By means of the two receiving means 10.21, 10.22, 10.23, 10.24, 10.25, 10.26 of each first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 or of each field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2, ​​each field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 or of each field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2 provides two measured quantities in the form of a 0° signal and a 90° signal, so that a total of eight measured quantities can be used for position determination.

[0083] For each first field interaction medium 10.X1, 10.X2, 10.Y1, 10.Y2 or field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2, ​​a linear position value X1, X2, Y1, Y2 in the corresponding measurement direction x, y, as well as a signal amplitude, is first determined from the 0° and 90° signals. The signal amplitude can be used to calculate a distance value Z_X1, Z_X2, Z_Y1, Z_Y2. The distance value Z_X1, Z_X2, Z_Y1, Z_Y2 of a first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 or field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2 quantifies the distance of the corresponding field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 or field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2 to the second interaction surface 21 of the second assembly 20 in the third measurement direction.

[0084] As in Fig. As shown in Figure 5, the first field interaction medium 10.X1 or the field interaction pair 10.PX1 provides the position value X1 for the first measurement direction x and the distance value Z_X1 for the third measurement direction z. Similarly, the first field interaction medium 10.X2 or the field interaction pair 10.PX2 provides the position value X2 for the first measurement direction x and the distance value Z_X2 for the third measurement direction z, the first field interaction medium 10.Y1 or the field interaction pair 10.PY1 provides the position value Y1 for the second measurement direction y and the distance value Z_Y1 for the third measurement direction z, and the first field interaction medium 10.Y2 or the field interaction pair 10.PY2 provides the position value Y2 for the second measurement direction y and the distance value Z_Y2 for the third measurement direction z.

[0085] Consequently, during a measuring cycle, the inductive position measuring device 1 provides two position values ​​X1, X2 for the first measuring direction x, two position values ​​Y1, Y2 for the second measuring direction y and four distance values ​​Z_X1, Z_X2, Z_Y1, Z_Y2 for the third measuring direction z.

[0086] In this way, the relative position of the first assembly 10 to the second assembly 20 can be determined in up to six degrees of freedom. Additionally, a statement can be made about the reliability of the determined values ​​by defining quality parameters, and further measures can be initiated based on these parameters if necessary.

[0087] The position of the center point M of the first assembly 10 can be determined, for example, by averaging the position values ​​X1, X2; Y1, Y2 of two first field interaction means 10.X1, 10.X2; 10.Y1, 10.Y2 or field interaction pairs 10.PX1, 10.PX2; 10.PY1, 10.PY2 running in an identical measurement direction x, y: X¯=X1+X22, where X represents the position value with respect to the first measurement direction x of the center point M of the first assembly 10; and Y¯=Y1+Y22, where Y represents the position value with respect to the second measurement direction y of the center point M of the first assembly 10.

[0088] The determination of the distance between the first assembly 10 and the second assembly 20 can be carried out in several ways, since each first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 or field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2 provides at least one distance value Z_X1, Z_X2, Z_Y1, Z_Y2: Z_X¯=Z_X1+Z_X22, where Z_X¯ for the averaged distance value in the third measurement direction z, which originates from the first field interaction means 10.X1, 10.X2 or the field interaction pairs 10.PX1, 10.PX2 running in the first measurement direction x, or Z_Y¯=Z_Y1+Z_Y22, where Z_Y¯ for the averaged distance value in the third measurement direction z, which is derived from the first field interaction means 10.Y1, 10.Y2 or the field interaction pairs 10.PY1, 10.PY2 running in the second measurement direction y.

[0089] The output value for the mean distance - i.e., the distance at the center M - of the first assembly 10 with respect to the second assembly 20 can be the mean of the two averaged distance values. Z_X¯,Z_Y¯ to be determined: Z¯=Z_X¯+Z_Y¯2, where Z represents the mean distance at the center M of the first assembly 10 with respect to the second assembly 20.

[0090] A deviation between the two averaged distance values Z_X¯,Z_Y¯ can be used to make a statement about the quality of the measurement results in the third measurement direction z: D_Z=Z_X¯−Z_Y¯, where D_Z represents a first quality parameter, by means of which a statement can be made about the quality of the measurement results in the third measurement direction z.

[0091] The Fig. 6a and Fig. Figure 6b shows a schematic top view of the inductive position measuring device 1, where only the first interaction surface 11 of the first assembly 10 is shown, comprising several paired first field interaction elements 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2''. The first and second assemblies 10, 20 are arranged opposite each other in two parallel planes, so that an air gap is formed between the first and second assemblies 10, 20. The first assembly 10 is located in Fig. 6a in a first position. Fig. Figure 6b shows the first assembly 10 from Fig. 6a, where it is now deflected and has assumed a second position. During the transition from the first to the second position, the first assembly 10 has undergone a relative rotation about the coordinate axis of the third measuring direction z. The second assembly 20 has remained stationary. The inductive position measuring device 1 is capable of determining and evaluating one or more relative rotations of the first assembly 10 in the three measuring directions x, y, z.

[0092] When determining the relative position of the first assembly 10 to the second assembly 20, a relative rotation about the coordinate axis in the first measurement direction x can be determined as follows: rot(X)=arcsin(Z_X2−Z_X1Dx), where rot(X) quantifies a rotation value around the coordinate axis of the first measurement direction x and Dx is the distance between the two first field interaction means 10.X1, 10.X2 or field interaction pairs 10.PX1, 10.PX2, which measure the linear position in the first measurement direction x.

[0093] A relative rotation around the coordinate axis of the second measurement direction y can also be determined in a similar way: rot(Y)=arcsin(Z_Y1−Z_Y2Dy), where rot(Y) quantifies a rotation value around the coordinate axis of the second measurement direction y and Dy is the distance between the two first field interaction means 10.Y1, 10.Y2 or field interaction pairs 10.PY1, 10.PY2, ​​which measure the linear position in the second measurement direction y.

[0094] The calculation of a rotation about the coordinate axis of the third measurement direction z can be done either via the equation rot(Z_X)=arcsin(X1−X2Dx) This is done where rot(Z_X) denotes a rotation value around the coordinate axis of the third measurement direction z based on the position values ​​X1, X2, and Dx is the distance between the two first field interaction means 10.X1, 10.X2 or field interaction pairs 10.PX1, 10.PX2, which measure the linear position in the first measurement direction x, or alternatively via the equation rot(Z_Y)=arcsin(Y2−Y1Dy), where rot(Z_Y) denotes a rotation value around the coordinate axis of the third measurement direction z based on the position values ​​Y1, Y2 and Dy denotes the distance between the two first field interaction means 10.Y1, 10.Y2 or the field interaction pairs 10.PY1, 10.PY2, ​​which measure the linear position in the second measurement direction y.

[0095] Since the independent rotation values ​​rot(Z_X), rot(Z_Y) are redundant, they can be used to determine the mean value of the rotation about the coordinate axis of the third measurement direction z. rot(Z)¯=rot(Z_X)+rot(Z_Y)2, where rot(Z) is the mean value of the rotation about the coordinate axis of the third measurement direction z.

[0096] By calculating the difference between the two independent rotation values ​​rot(Z_X), rot(Z_Y), a quality parameter D_rot(Z) can be quantified, which can be used as information about the reliability of the measurement values ​​in the first and second measurement directions x, y. D_rot(Z)=rot(Z_X)−rot(Z_Y), where D_rot(Z) represents a second quality parameter, which allows a statement to be made about the reliability of the rotation values ​​in the third measurement direction z.

[0097] The inductive position measuring device 1 thus has, in addition to the position values ​​X1, X2, Y1, Y2, the mean values ​​X, Y, Z, Z_X¯,Z_Y¯, In addition to the distance values ​​Z_X1, Z_X2, Z_Y1, Z_Y2 and the rotation values ​​rot(X), rot(Y), rot(Z_X), rot(Z_Y) within a measurement cycle, the two quality parameters D_Z and D_rot(Z) are also available. The smaller the values ​​of these quality parameters, the more accurate the measurement results of the inductive position measuring device 1, or the more reliable the position and distance values ​​can be.

[0098] The quality parameters D_Z and D_rot(Z) can, for example, be used to output an error signal if either parameter exceeds a predefined threshold. Additionally or alternatively, exceeding a threshold can trigger an optimization procedure to correct the cross-sensitivity of the individual first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2, or field interaction pairs 10.PX1, 10.PX2, 10.PY1, 10.PY2.

[0099] As in the Fig. 6a and Fig. As shown schematically in Figure 6b, position determination is preferably carried out on the basis of those field interaction pairs 10.PX1, 10.PX2, 10.PY1, 10.PY2 in which a sufficiently strong coupling develops, i.e. for those field interaction pairs 10.PX1, 10.PX2, 10.PY1, 10.PY2 and second field interaction means 20.1 to 20.n which at least partially overlap when viewed from the top in the third measurement direction z. Advantageously, the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'' are each larger than the second field interaction means 20.1 to 20.n, so that several second field interaction means 20.1 to 20.n are always superimposed on at least one first field interaction mean 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2''. In particular, the receiving means 10.23, 10.24, 10.25, 10.26 of the first field interaction means 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'' several second field interaction means 20.1 to 20.n.

[0100] Fig. Figure 7 schematically shows a cross-section through the first and second assemblies 10, 20 of the inductive position measuring device 1.

[0101] The first assembly 10 comprises evaluation electronics 10.3, which individually applies a predetermined excitation signal S1 to each individual field interaction element 10.X1, 10.X2, 10.Y1, 10.Y2 or each individual field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2. Specifically, when applying the excitation signal S1 to a first field interaction element 10.X1, 10.X2, 10.Y1, 10.Y2 or field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2, ​​at least one excitation element 10.1 emits the excitation signal S1 in the form of an electromagnetic field or one or more electromagnetic waves. The excitation signal S1 is emitted from the first module 10 towards the second module 20 and encounters at least one and preferably several second field interaction means 20.1 to 20.n. The excitation signal S1 is received by the second field interaction means 20.1 to 20.n.n modulated and emitted in the form of at least one received signal S2 from the second assembly 20 back to the first assembly 10 in the form of an electromagnetic field or one or more electromagnetic waves.

[0102] The received signal S2 is then detected by at least one first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2 or field interaction pair 10.PX1, 10.PX2, 10.PY1, 10.PY2 and a signal evaluation is carried out by the evaluation electronics 10.3.

[0103] The evaluation electronics 10.3 can, for example, include a microcontroller, a resonant circuit, an ASIC and several multiplexers.

[0104] The position values ​​X1, X2, Y1, Y2 and distance values ​​Z_X1, Z_X2, Z_Y1, Z_Y2 determined by the signal evaluation are used to determine the previously described mean values, rotation values ​​and quality parameters.

[0105] Advantageously, the modulation of the excitation signal S1 within the second field interaction medium 20.1 to 20.n is achieved by forming eddy currents.

[0106] Preferably, every second field interaction means 20.1 to 20.n is constructed identically and all second field interaction means 20.1 to 20.n are arranged equidistantly apart from each other in a grid.

[0107] Position determination is performed within a predefined measuring range according to an absolute measurement method. The measuring range depends on the length of the first field interaction means 10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'' in the corresponding measuring direction x, y, or on the resulting 0° and 90° signals.

[0108] At the start of the measurement, the first and second assemblies 10, 20 are aligned relative to each other within the measuring range, for example by centering the first assembly 10 relative to the second assembly 20 (see Fig. 6a) If the first assembly 10 is deflected relative to the second assembly 20, the absolute position of the first assembly within the measuring range can be determined.

[0109] Preferably, the area of ​​the second interaction surface 21 is smaller than or equal to the area of ​​the measuring range. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 088 869 A1

[0002] EP 23200280

[0054]

Claims

[1] Inductive position measuring device (1) comprising a first assembly (10) with a first interaction surface (11) and a second assembly (20) with a second interaction surface (21), wherein the assemblies (10, 20) are arranged opposite each other in a third measuring direction (z) and are movable relative to each other, where the second interaction surface (21) is larger than the first interaction surface (11), wherein the first assembly (10) comprises several first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') which are arranged parallel to the first interaction surface (21), wherein the second assembly (20) comprises several second field interaction means (20.1 to 20.n) which are arranged in a planar distribution over the second interaction surface (21), wherein the first and second field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2''; 20.1 to 20.n) can be brought into electromagnetic interaction, characterized by , that at least one first field interaction means (10.X1, 10.X2; 10.X1', 10.X1'', 10.X2', 10.X2'') is arranged along a first measuring direction (x) and at least one further first field interaction means (10.Y1, 10.Y2; 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') is arranged along a second measuring direction (y), and that the first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') each have at least one excitation means (10.1; 10.2) for generating an electromagnetic field and comprising at least one receiving means (10.21, 10.22; 10.23, 10.24, 10.25, 10.26) for receiving an electromagnetic field. [2] Inductive position measuring device according to claim 1, characterized by , that the first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') are designed as elongated linear sensors and the first and second measuring directions (x, y) are perpendicular to each other. [3] Inductive position measuring device according to at least one of the preceding claims, characterized by , that the first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') • each comprising a first receiving means (10.21; 10.23, 10.25) and a second receiving means (10.22; 10.24, 10.26) which have a periodic profile with a constant period length (T1; T2), wherein the receiving means (10.21, 10.22; 10.23, 10.24, 10.25, 10.26) are arranged offset from each other by one quarter of their period length (T1; T2) in the first or second measuring direction (x, y), and • each comprising an inducing agent (10.1; 10.2) which surrounds the two receiving agents (10.21, 10.22; 10.23, 10.24, 10.25, 10.26). [4] Inductive position measuring device according to at least one of the preceding claims, characterized by , that the first assembly (10) comprises four first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2) which are arranged in the first interaction surface (21) and each perpendicular to each other. [5] Inductive position measuring device according to claims 3 and 4, characterized by, that the receiving means (10.21, 10.22) of the four first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2) are designed such that they have a oscillation width (SB1) that corresponds to at least one period length (T1). [6] Inductive position measuring device according to one of claims 1 to 3, characterized by , that the first assembly (10) comprises eight first field interaction means (10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') which are arranged in the first interaction surface (21) and in four pairwise parallel field interaction pairs (10.PX1, 10.PX2, 10.PY1, 10.PY2), wherein the four field interaction mean pairs (10.PX1, 10.PX2, 10.PY1, 10.PY2) are each arranged perpendicular to each other. [7] Inductive position measuring device according to claims 3 and 6, characterized by , • that the first receiving means (10.23, 10.25) of at least one field interaction pair (10.PX1, 10.PX2, 10.PY1, 10.PY2) are identical and connected in series, • that the second receiving means (10.24, 10.26) of at least one field interaction pair (10.PX1, 10.PX2, 10.PY1, 10.PY2) are identical and connected in series, • that the receiving means (10.23, 10.24, 10.25, 10.26) of the field interaction pairs (10.PX1, 10.PX2, 10.PY1, 10.PY2) are designed such that they have a oscillation width (SB2) that is less than half the period length (T2), • that the distance (V3) between two receiving means (10.23, 10.24; 10.25, 10.26) within at least one field interaction pair (10.PX1, 10.PX2, 10.PY1, 10.PY2) is half the period length (T2). [8] Inductive position measuring device according to at least one of the preceding claims, characterized by, that the second assembly (20) is not connected to an active power supply and data processing unit. [9] Inductive position measuring device according to at least one of the preceding claims, characterized by , that the second field interaction means (20.1 to 20.n) • are rectangular, especially square, in shape and • are of equal size and uniformly distributed in a grid pattern on the second interaction surface 21. [10] Inductive position measuring device according to at least one of the preceding claims, characterized by , that the second field interaction means (20.1 to 20.n) are produced using a planar technology, in particular by thick-film technology and / or thin-film technology. [11] Method for operating an inductive position measuring device according to at least one of the preceding claims, characterized by, that using at least one first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') a predetermined excitation signal (S1) is sent to the second assembly (20), wherein a received signal (S2) present at at least one first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2'') is measured separately, wherein by appropriate signal evaluation of at least one received signal (S2) a linear position information (X1, X2, Y1, Y2) and / or a distance information (Z_X1, Z_X2, Z_Y1, Z_Y2) of the at least one first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2''). [12] Method according to claim 11, characterized by, that the relative position of the first and second assembly (10, 20) is determined in at least four degrees of freedom by the inductive position measuring device (1). [13] Method according to one of claims 11 or 12, characterized by , that from the position information (X1, X2, Y1, Y2) and / or distance information (Z_X1, Z_X2, Z_Y1, Z_Y2) of the first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2''), which determine position information (X1, X2; Y1, Y2) and / or distance information (Z_X1, Z_X2, Z_Y1, Z_Y2) with respect to an identical measurement direction (x, y, z), at least a first quality parameter is derived. [14] Method according to any one of claims 11 to 13, characterized by, that from the position information (X1, X2, Y1, Y2) and / or distance information (Z_X1, Z_X2, Z_Y1, Z_Y2) of the first field interaction means (10.X1, 10.X2, 10.Y1, 10.Y2; 10.X1', 10.X1'', 10.X2', 10.X2'', 10.Y1', 10.Y1'', 10.Y2', 10.Y2''), at least one rotation information (rot(X), rot(Y), rot(Z)) about an axis oriented in one of the measurement directions (x, y, z) is determined. [15] Method according to claim 14, characterized by , that at least one second quality parameter is derived from the at least one rotation information (rot(X), rot(Y), rot(Z)). [16] Method according to claims 13 and 15, characterized by , that depending on the first quality parameter and / or the second quality parameter, an error signal is output and / or an optimization procedure is carried out.

Images