INDUCTIVE ANGLE SENSOR WITH DISTANCE VALUE DETERMINATION

Abstract

Including inductive angle sensor (100): a stator (101) with an excitation resonant circuit (103, 104) and a pickup coil arrangement (105), a rotor (102) rotatably arranged relative to the stator (101) with an inductive target arrangement (106), wherein the excitation resonant circuit (103, 104) can be excited with an alternating current in order to induce an induced current in the target arrangement (106), and wherein the target arrangement (106) is configured to generate a magnetic field (116) in response to the induced current, which in turn generates induction signals (S i_PS1 , S i_PS2 ) generated in the pickup coil arrangement (105), wherein the angle sensor (100) further comprises a circuit (108) which is configured to derive from a combination of the induction signals (S i_PS1 , S i_PS2 ) an induction strength signal (S i ) to derive the signal strength of the induction signals (S i_PS1 , S i_PS2) of the pickup coil arrangement (105) represents, and the spatial distance (107) between the rotor (102) and the stator (101) based on the induction strength signal (S i ) to determine and generate a corresponding distance signal (204), and wherein the circuit (108) is designed to measure the induction strength signal (S i ) with the current (I1) in the excitation resonant circuit (103, 104) into a ratio (S i / I1) to each other and based on this relationship (S i / I1) to determine the spatial distance (107) between the rotor (102) and the stator (101) and to output it as a corresponding distance signal (204).

Description

[0001] The present disclosure relates to an inductive angle sensor for determining a rotation angle between a stator and a rotor. Some embodiments may provide that the inductive angle sensor uses a calibrated rotation angle signal, determined taking into account the spatial distance between the rotor and the stator, to determine the rotation angle. Further embodiments relate to a corresponding method for determining the rotation angle between the stator and the rotor based on the calibrated rotation angle signal. Further embodiments relate to a computer program with program code for carrying out this method.

[0002] Inductive angle sensors utilize inductances, induced eddy currents, and corresponding magnetic fields. They therefore differ in their construction from classic magnetic field sensors, such as Hall sensors or magnetoresistive (MR) sensors, such as AMR sensors (AMR: Anisotropic Magnetoresistive), TMR sensors (TMR: Tunnel Magnetoresistive), or GMR sensors (GMR: Giant Magnetoresistive).

[0003] Inductive angle sensors typically consist of an excitation resonant circuit, an inductive target, and a receiving coil, also known as a pickup coil. The excitation resonant circuit can be driven by an alternating voltage or current, generating a magnetic field that in turn induces a current in the target. This current, in turn, creates a corresponding magnetic field that generates an inductive signal, such as an induced current or voltage, in the pickup coil.

[0004] The target and the pickup coil are positioned opposite each other. The induction signal received by the pickup coil depends, among other things, on the angle-specific position or positioning of the target relative to the pickup coil; that is, the signal strength of the induction signal changes depending on the angle-specific position of the target relative to the pickup coil. The rotation angle of the target relative to the pickup coil can be determined from this.

[0005] For example, German patent application DE 10 2019 213 174 B9 describes such an inductive angle sensor, which serves to determine the rotational position of a rotor relative to a stator. The angle sensor comprises an excitation coil, at least one pickup coil arrangement with m-fold symmetry, and at least one conductive target with m-fold symmetry. The excitation coil can excite the conductive target, which in turn can induce a signal in the pickup coil arrangement. A signal analyzer can determine the rotational position of the rotor based on the induced signal. The inductive angle sensor comprises a second pickup coil arrangement with n-fold symmetry and a second conductive target with n-fold symmetry. The excitation coil can excite the second conductive target, which in turn induces a second signal in the second pickup coil arrangement.The signal analysis device can determine the rotational position of the rotor based on the two induced signals according to a vernier principle.

[0006] For some applications, however, state-of-the-art inductive angle sensors are not precise enough. This is partly because the accuracy of the inductive signal depends on many factors, such as the quality factor of the excitation circuit, the number and geometry of the coils used, and the spatial distances between the individual coils.

[0007] Increasing the quality factor of the resonant circuit, as well as increasing the number of component parts, is associated with higher costs, and the spatial distances between the individual sensor components are usually fixed by the assembly technology used or can only be varied within narrow limits.

[0008] It would therefore be desirable to improve existing inductive angle sensors so that they provide precise signals based on a calibrated rotation angle signal determined taking into account the spatial distance between the rotor and the stator, and which are also inexpensive to manufacture.

[0009] Therefore, according to a first aspect, an inductive angle sensor with the features of claim 1 is proposed.

[0010] The angle sensor comprises a stator with an excitation resonant circuit and a pickup coil arrangement, as well as a rotor rotatably mounted relative to the stator, featuring an inductive target arrangement. The excitation resonant circuit can be driven by an alternating current to induce an inductive current in the target arrangement. The target arrangement, in turn, is configured to generate a magnetic field in response to this inductive current, which in turn generates inductive signals in the pickup coil arrangement. The angle sensor, according to the innovative concept described herein, further comprises a circuit configured to derive an inductive strength signal representing the signal strength of the inductive signals from the inductive signals themselves, and to determine the spatial distance between the rotor and the stator based on this inductive strength signal, generating a corresponding distance signal.According to the invention, the circuit is designed to relate the induction strength signal to the current in the excitation resonant circuit and, based on this ratio, to determine the spatial distance between the rotor and the stator and output it as a corresponding distance signal.

[0011] According to a second aspect, an inductive angle sensor with the features of claim 3 is proposed.

[0012] This inductive angle sensor comprises a stator with an excitation resonant circuit and a pickup coil assembly, and a rotor rotatably mounted relative to the stator with an inductive target assembly. The excitation resonant circuit can be driven with an alternating current to induce an inductive current in the target assembly. The target assembly is configured to generate a magnetic field in response to the inductive current, which in turn generates inductive signals in the pickup coil assembly. The angle sensor further comprises a circuit configured to derive an inductive strength signal from a combination of the inductive signals. This signal represents the signal strength of the inductive signals in the pickup coil assembly. Based on this inductive strength signal, the spatial distance between the rotor and the stator is determined, and a corresponding distance signal is generated.The pickup coil arrangement comprises a first pickup coil pair with a first pickup coil and a second pickup coil, and a second pickup coil pair with a third pickup coil and a fourth pickup coil. The target arrangement comprises a first inductive target and a second inductive target, wherein the first pickup coil pair has a first spatial distance to the first inductive target, and wherein the second pickup coil pair has a second spatial distance to the second inductive target that differs from the first spatial distance. The first pickup coil pair generates a first pickup coil pair signal, from which a first coil pair inductance signal can be derived, and the second pickup coil pair generates a second pickup coil pair signal, from which a second coil pair inductance signal can be derived.According to the invention, the circuit is designed to relate the first coil pair induction strength signal and the second coil pair induction strength signal to each other and to determine the spatial distance between the rotor and the stator based on this ratio.

[0013] Embodiments and further advantageous aspects of this inductive angle sensor are mentioned in the respective dependent patent claims.

[0014] Some exemplary embodiments are shown in the drawing and are explained below. They show: Fig. 1 a schematic side view of an inductive angle sensor according to an exemplary embodiment, Fig. 2 a schematic block diagram of a circuit of an inductive angle sensor according to an exemplary embodiment, Fig. 3 a schematic top view of an excitation resonant circuit or an excitation coil and a pickup coil pair of an inductive angle sensor according to an embodiment, Fig. 4 a schematic block diagram of a circuit of an inductive angle sensor according to an exemplary embodiment, Fig. 5 a schematic view of a stator, a rotor and a circuit of an inductive angle sensor according to an embodiment with a pickup coil pair, Fig. 6A a schematic view of a stator, a rotor and a circuit of an inductive angle sensor according to an embodiment with two pickup coil pairs, Fig. 6B a schematic side view of a stator with two pickup coil pairs and a rotor with two inductive targets according to an embodiment, Fig. 7 a schematic view of a stator and circuit of an inductive angle sensor according to an exemplary embodiment, and Fig. 8 a block diagram of a method according to an exemplary embodiment.

[0015] The following are examples of embodiments described in more detail with reference to the figures, whereby elements with the same or similar function are provided with the same reference numerals.

[0016] Process steps depicted in a block diagram and explained with reference to it can also be executed in a different sequence than the one shown or described. Furthermore, process steps relating to a specific feature of a device are interchangeable with that very feature of the device, and vice versa.

[0017] Fig. Figure 1 shows a first embodiment of an inductive angle sensor 100 according to the innovative concept described herein.

[0018] The inductive angle sensor 100 has a stator 101 and a rotor 102 rotatably arranged relative to the stator 101. The inductive angle sensor 100 is designed to determine an actual or real rotation angle φ between the rotor 102 and the stator 101. The actual rotation angle φ is also referred to as phi in some instances herein.

[0019] The stator 101 has an excitation resonant circuit 103. The excitation resonant circuit 103 can include at least one inductor, for example, a corresponding excitation coil 104. The excitation coil 104 is electrically conductive and can have one or more turns. The excitation coil 104 can also be referred to as an excitation coil or exciter coil. The excitation resonant circuit 103 can optionally include an oscillator and further optionally a resistor and / or a capacitor (not shown). The stator 101 can also include a pickup coil arrangement 105, which can also be referred to as a receiver coil arrangement.

[0020] The rotor 102, which is rotatably arranged relative to the stator 101, can have at least one inductive target arrangement 106. The target arrangement 106 can also have a coil with one or more turns or be designed as such a coil. Alternatively, the target arrangement 106 can have a solid component, for example a stamped sheet metal part, or be designed as such.

[0021] In principle, the excitation resonant circuit 103 or the excitation coil 104, the pickup coil assembly 105, and the target assembly 106 can be arranged along a common axis of rotation 109 or vertically stacked one above the other along the common axis of rotation 109. The excitation coil 104, the pickup coil assembly 105, and the target assembly 106 can be arranged concentrically around the common axis of rotation 109. The respective diameters of the excitation coil 104, the pickup coil assembly 105, and the target assembly 106 can differ. For example, the diameter of the excitation coil 104 can be larger than the diameter of the pickup coil assembly 105 and / or the target assembly 106.

[0022] The excitation resonant circuit 103, and in particular the excitation coil 104, can be excited by an alternating current or an alternating voltage. In response to this alternating current or voltage, the excitation coil 104 can generate a magnetic field 114, which can be directed outwards, and in particular in the direction of the rotor 102. The target arrangement 106, located in or on the rotor 102, is magnetically coupled to the excitation coil 104, which is located in or on the stator 101. That is, the target arrangement 106 can receive the magnetic field 114 generated by the excitation coil 104, which in turn induces a corresponding induced current in the target arrangement 106. The excitation coil 104 can be rotationally symmetrical. Thus, an induced current flows in the target arrangement 106, which is independent of the actual rotation angle φ of the rotor 102 relative to the stator 101.The induced current in the target arrangement 106 in turn causes a magnetic field 116 in the target arrangement 106, which can be directed outwards, and in particular towards the stator 101. The magnetic field 116 can exhibit a magnetic field pattern that depends on the geometric shape of the target arrangement 106. That is, the generated magnetic field pattern can be fixedly coupled to the respective target arrangement 106.

[0023] The magnetic field 116 emanating from the target arrangement 106 can be received by the pickup coil arrangement 105 located in or on the stator 101. If the rotor 102 moves relative to the stator 101, the magnetic field 116 emanating from the target arrangement 116, or the corresponding magnetic field pattern, also moves relative to the stator 101. This means that if an observer rotates synchronously with the target arrangement 106, they will not see any change in the magnetic field. However, in the stator 101, which is moving relative to the rotor 102, a change in the magnetic field can be seen at a fixed location because the entire magnetic field pattern is also moving. This results in induction signals S being generated in the pickup coil arrangement 105 in response to the changing magnetic field 116. i_PS1 , S i_PS2 e.g., induced currents or induced voltages. The signal strength of the two induced signals S i_PS1 , S i_PS2 can be achieved by a corresponding induction strength signal S ican be expressed, which in turn is derived from the two induction signals S i_PS1 , S i_PS2 This can be derived. Details will be explained in more detail below. The signal strength or the amplitude of the induction signal S i This can depend on the strength of the received magnetic field 116.

[0024] The strength of the magnetic field 116 at a fixed location can depend on the current position, i.e., the actual rotation angle φ between the rotor 102 and the stator 101. However, if the location moves / rotates synchronously with the rotor 102, then there is no change. If, however, the spatial distance 107 between the rotor 102 and the stator 101 changes, then there is a change in the strength of the magnetic field 116 and thus in the signal strength, which is determined by the induction signal S. i can be expressed.

[0025] As in Fig. As shown schematically and not to scale in Figure 1, a variable spatial distance 107 exists between the stator 101 and the rotor 102 due to the design. This spatial distance 107 can be measured between the two opposing surfaces 101a, 102a of the rotor 102 and the stator 101. For example, air may be present between the rotor 102 and the stator 101, which is why the spatial distance 107 can also be referred to as an air gap (abbreviated as 'AG'). Alternatively, the spatial distance 107 can also be measured as the average distance between the rotor 102 and the stator 101, where the distance is measured between the respective horizontal (i.e., perpendicular to the axis of rotation 109) center lines 101b, 102b of the rotor 102 and the stator 101, respectively. In this case, in addition to the air gap, the corresponding material thickness of the rotor 102 or the stator 101 would also have to be taken into account in the spatial distance 107.

[0026] The spatial distance 107 between the stator 101 and the rotor 102 can vary due to design factors; that is, different inductive angle sensors of different designs can have different spatial distances 107 between their respective rotor 102 and stator 101. Even angle sensors of the same design can have different spatial distances 107 between their respective rotor 102 and stator 101, for example, due to assembly tolerances. The spatial distance 107 between rotor 102 and stator 101 can therefore be specific to each angle sensor.

[0027] In addition, the pickup coil arrangement 105 can have several coils and / or the target arrangement 106 can have several inductive targets, which in turn can have different spatial distances from each other.

[0028] However, different spatial distances 107 between rotor 102 and stator 101 and / or between individual coils cause different signal strengths of the induced currents or the induced magnetic fields 114, 116. This can lead to inaccuracies and deviations in determining the actual rotation angle φ of rotor 102 relative to stator 101. For example, an angle sensor with a large spatial distance 107 between rotor 102 and stator 101 will register a weaker induced signal S i supply as an angle sensor with a relatively smaller spatial distance 107 between rotor 102 and stator 101.

[0029] Furthermore, the spatial distance 107 specific to each angle sensor is generally unknown. Theoretically, this spatial distance 107 would have to be measured for each individual angle sensor 100 before delivery. However, this is not feasible in practice due to the high effort and associated costs.

[0030] The angle sensor 100 described herein provides a remedy in this regard by taking the spatial distance 107 into account when determining the actual rotation angle φ between the rotor 102 and the stator 101. For this purpose, the angle sensor 100 can have a circuit 108 which is designed to calculate the spatial distance 107, also referred to as air gap (abbreviated: 'AG'), between the rotor 102 and the stator 101 based on the induction signal S. i to determine and a corresponding distance signal 204 (S AG to generate.

[0031] Fig. Figure 2 shows a schematic block diagram of a corresponding circuit 108 according to the innovative concept described herein. The circuit 108 can, for example, include an angle calculation unit 201, a distance measurement unit 202, and a calibration unit 203.

[0032] The circuit 108 can, for example, use the previously mentioned distance signal 204 to determine a calibrated rotation angle signal 110, also referred to herein as phi" or φ". This calibrated rotation angle signal phi" represents the actual current rotation angle φ between the stator 101 and the rotor 102. In contrast to conventional angle sensors, the calibrated rotation angle signal phi" can be determined based on the induction strength signal S iand / or based on the distance signal 204, i.e., taking into account the spatial distance 107 between the rotor 102 and the stator 101. That is, the spatial distance 107 can be determined and used to determine the actual rotation angle φ based on the induction strength signal S. i The inductive angle sensor 100, according to the innovative concept described herein, therefore provides a rotation angle signal phi" corrected or compensated by the determined spatial distance 107. This process can be essentially compared to a calibration, so that the corresponding signal can also be referred to as a calibrated rotation angle signal phi".

[0033] Circuit 108 can also be configured to output the determined distance signal 204 to increase the reliability of the inductive angle sensor 100. For example, if the value of the distance signal 204 is too high, it could be unreliable, and the inductive angle sensor 100 could switch to emergency mode. This means that determining the distance signal 204 could be used to improve the positional accuracy and / or increase the reliability of the inductive angle sensor 100.

[0034] One way to determine the distance signal 204 will be described below, with reference to Fig. 2, will be explained in more detail. The induction strength signal S i , which is derived from the induction signals S generated by the pickup coil arrangement 105 i_PS1 , S i_PS2The angle calculation unit 201 can be derived and fed to it. The angle calculation unit 201 can be designed to calculate the angle based on the induction strength signal S. i to determine an uncalibrated rotation angle signal phi', which represents an uncalibrated angle value. The uncalibrated angle value phi' corresponds to the measured actual rotation angle φ between the rotor 102 and the stator 101 at an uncalibrated or coarse resolution, i.e., without taking into account the spatial distance 107 between the rotor 102 and the stator 101.

[0035] According to the invention, the induction strength signal S iThe distance measurement unit 202 is supplied with a signal. The distance measurement unit 202 is configured to determine the spatial distance 107 between the rotor 102 and the stator 101. Specifically, the distance measurement unit 202 is configured to determine the spatial distance 107 between the rotor 102 and the stator 101 based on the spatial distance between the pickup coil arrangement 105 and the target arrangement 106. Details are explained in more detail with reference to the following figures. According to the invention, the distance measurement unit 202 generates a distance signal 204 that represents the determined spatial distance 107 between the rotor 102 and the stator 101.

[0036] The distance signal 204 output by the distance measurement unit 202 can be fed to the calibration unit 203. The calibration unit 203 can be configured to determine an angle correction value dphi' based on the distance signal 204 and to output a corresponding angle correction value signal dphi'. The angle correction value dphi' indicates the deviation of the measured rotation angle phi' between the rotor 102 and the stator 101 from the actual rotation angle φ between the rotor 102 and the stator 101, whereby this deviation can result from the spatial distance 107 between the rotor 102 and the stator 101.

[0037] The circuit 108 can further comprise a combiner 205, which is configured to combine the angle correction value signal dphi' output by the calibration unit 203 with the uncalibrated rotation angle signal phi' output by the angle calculation unit 201. The uncalibrated rotation angle signal phi' output by the angle calculation unit 201, which represents the actual rotation angle φ between the rotor 102 and the stator 101 at a coarse resolution, can thus be corrected or compensated by the determined angle correction value dphi'. As a result, the combiner 205 can output a corrected or calibrated rotation angle signal phi". The calibrated rotation angle signal phi" represents the actual rotation angle φ between the rotor 102 and the stator 101 at a higher or more accurate resolution, i.e., taking into account the spatial distance 107 between the rotor 102 and the stator 101.In other words, the calibration unit 203 can be designed to determine the angle correction value signal dphi' based on the distance signal 204 and to take the corresponding angle correction value dphi' into account when determining the calibrated rotation angle signal phi".

[0038] For this purpose, circuit 108 can, for example, be configured to determine the angle correction value dphi' from the distance signal 204 using a mathematical calculation procedure, e.g., a formula or an algorithm. Alternatively or additionally, circuit 108 can be configured to determine the angle correction value dphi' from the distance signal 204 using a lookup table. The lookup table can be populated with values ​​that link a specific signal strength of the distance signal 204 with a concrete numerical value for the spatial distance 107 between the rotor 102 and the stator 101.

[0039] Fig. Figure 3 shows a schematic view of an excitation resonant circuit 103 or an excitation coil 104 and a pickup coil arrangement 105 according to an exemplary embodiment. In this exemplary embodiment, the pickup coil arrangement 105 has a pickup coil pair 115 with a first pickup coil 115a and a second pickup coil 115b.

[0040] The two pickup coils 115a, 115b of the pickup coil pair 115, or the pickup coil arrangement 105, can exhibit n-fold symmetry or n-fold rotational symmetry. In this non-limiting example, the pickup coil arrangement 105 can exhibit threefold symmetry, i.e., n = 3. A body is called rotationally symmetric if, after a rotation around its center by a defined angle, specifically 360° / n, it maps back onto itself. The angle of rotation can be an integer divisor n of the full angle. This integer n is a characteristic of the n-fold rotational symmetry and is also called its "foldiness." Accordingly, this symmetry is also called n-fold rotational symmetry (analogous to the English "n-fold rotational symmetry") or "n-fold rotational symmetry."In other words, a body can have n-fold symmetry if and only if it can be rotated 360°*k / n about an axis (where n and k are integer variables) and it looks the same after the rotation. In this regard, reference is made to the German patent specification with publication number DE 10 2019 213 174 B9.

[0041] As further illustrated by example and schematically in Fig. As shown in Figure 3, the two pickup coils 115a, 115b can have an identical geometric shape and be arranged offset from each other, or rotated relative to each other about the common axis of rotation 109. According to the invention, the two pickup coils 115a, 115b are offset from each other such that the first pickup coil 115a generates a first pickup coil signal S i_PS1 and the second pickup coil 115b to the first pickup coil signal S i_PS1 different and phase-shifted second pickup coil signal S i_PS2generated. For example, these can be orthogonal pickup coil signals, where the first pickup coil signal S i_PS1 at 90° relative to the second pickup coil signal S i_PS2 is out of phase.

[0042] Orthogonal signals are, by definition, sinusoidal signals with a 90° phase shift. This can be achieved, for example, by rotating one pickup coil 115a relative to the other pickup coil 115b by 360° / n / 4 along the direction of movement. However, it is also possible to rotate the pickup coils 115a and 115b relative to each other by a different angle, so that their signals are then phase-shifted by a different angle, e.g., 60° or 45°.

[0043] With the sinusoidal waveform of the pickup coil signals S described herein i_PS1 , S i_PS2The sinusoidal waveform as a function of the travel distance or rotor position (i.e., the actual rotation angle φ between rotor 102 and stator 101) is meant, and not the sinusoidal signal waveform as a function of time. The pickup coil arrangement 105 can be excited with alternating voltage and thus oscillate several million times per second. However, this (possibly sinusoidal) oscillation is not what is meant here; rather, those components of the pickup coil signals S are being referred to. i_PS1 , S i_PS2 Consider the components that remain after demodulation – that is, after the time-varying part of the oscillation has been eliminated. These depend on the rotor angle (i.e., the actual rotation angle φ between rotor 102 and stator 101).

[0044] According to the embodiment in Fig. 3, in which the two pickup coils 115a, 115b are rotated 30° relative to each other, the first pickup coil signal S can be i_PS1essentially following a cosine waveform and the second pickup coil signal S i_PS2 can essentially follow a sine waveform, i.e., S i_PS1 = S i cos and S i_PS2 = S i sin. A combination of the two pickup coil signals S i_PS1 , S i_PS2 It can provide an unambiguous angular signal, at least in a partial segment of a full 360° period, from which the actual rotation angle φ between the stator 101 and the rotor 102 can be derived. Reference is also made in this regard to the German patent specification with publication number DE 10 2019 213 174 B9.

[0045] Fig. Figure 4 shows a schematic block diagram of another non-limiting embodiment of an inductive angle sensor 100. The setup is essentially similar to the one described previously with reference to Fig. 2 discussed embodiment, wherein elements with the same reference numeral have the same function.

[0046] The in Fig. The embodiment shown in Figure 4 can have a pickup coil pair 115 with n-fold symmetry. To avoid short circuits, the two individual pickup coils 115a, 115b can be arranged contactlessly and at least partially in different planes along the common axis of rotation 109, for example, in different metallization layers within a substrate, such as within a PCB (Printed Circuit Board). The two pickup coils 115a, 115b arranged in or on the stator 101 can thus have different spatial distances from the rotor 102 or from the target arrangement 106 arranged in or on the rotor 102. This can lead to deviations in the angular measurement of the relative rotation angle φ between the rotor 102 and the stator 101.

[0047] The in Fig. However, the exemplary circuit 108 shown in Figure 4 can reduce or compensate for this angular deviation and thus calibrate the inductive angle sensor 100. The first pickup coil 115a shown here as an example generates a first pickup coil signal S, for example, a cosine-shaped signal. i_PS1 , and the second pickup coil 115b generates a second pickup coil signal S that is essentially 90° out of phase with the first and thus approximately sinusoidal. i_PS2 , i.e. S i_PS1 = S i cos and S i_PS2 = S i sin.

[0048] This phase shift between the two pickup coil signals S i_PS1 and S i_PS2 allows a unique determination of the actual rotation angle φ between the rotor 102 and the stator 101 based on a combination of the two pickup coil signals S i_PS1 and S i_PS2 of the two pickup coils 115a, 115b according to the present invention. The previously discussed induction strength signal Si The pickup coil arrangement 105 is, according to the invention, formed from such a combination of the two pickup coil signals S i_PS1 and S i_PS2 , for example via a suitable tangent operation of the two pickup coil signals S i_PS1 and S i_PS2 , derived. One possible calculation would be possible, for example, using the following rule: φ=ATAN2(SiPS2,SiPS1)

[0049] The determination of the actual rotation angle φ between the rotor 102 and the stator 101 can be unique, at least over a certain partial range of a full 360° rotation. This, in turn, depends on the degree of rotational symmetry of the two pickup coils 115a and 115b. For example, the determination of the actual rotation angle φ between the rotor 102 and the stator 101 is unique within an angular range of 360° / n. With triple symmetry, the actual rotation angle φ would therefore be uniquely determinable within a range of 120°.

[0050] As in Fig. As can be seen in section 4, the two pickup coil signals S i_PS1 and S i_PS2 supplied to the angle calculation unit 201, which can calculate an uncalibrated angle signal phi' from it, i.e. without taking into account the spatial distance 107 between the rotor 102 and the stator 101.

[0051] The two pickup coil signals S i_PS1 and S i_PS2 are also fed to the distance measurement unit 202, which determines the spatial distance 107 between the rotor 102 and the stator 101 and outputs a corresponding distance signal 204.

[0052] The distance signal 204 can be fed to the calibration unit 203. Taking into account the value of the distance signal 204, the calibration unit 203 can calculate a corresponding angle correction value dphi', which in turn can be fed to the combiner 205. The combiner 205 can combine the uncalibrated angle value phi' with the angle correction value dphi' and generate a calibrated rotation angle signal phi" from it, e.g., phi" = phi' ± dphi'. The calibrated rotation angle signal phi" represents the actual rotation angle φ between the rotor 102 and the stator 101, taking into account the spatial distance 107 between the rotor 102 and the stator 101.

[0053] This allows the angular error to be reduced or compensated, resulting in a significantly more accurate value for the actual rotation angle φ compared to conventional uncalibrated angle sensors.

[0054] In other words, the circuit 108 can be configured to first calculate a rough estimate of the actual rotation angle φ in the angle calculation unit 201 and output a corresponding uncalibrated rotation angle signal phi'. In the distance determination unit 202, the spatial distance 107 between the rotor 102 and the stator 101 is estimated, and a corresponding distance signal 204 is output. In the calibration unit 203, the estimated distance value 204 can be combined with a corresponding angular error, for example, using a mathematical calibration formula and / or a calibration table. The angular error can be output as an angle correction signal dphi'. The angle correction signal dphi' can be a function of the distance value 204, i.e., dphi' = f(distance value).

[0055] As mentioned at the outset, the spatial distance 107 between the rotor 102 and the stator 101 is determined based on the spatial distance between the pickup coil assembly 105 and the target assembly 106. According to the innovative concept described herein, this can be done in various ways. Some non-limiting examples of this will be explained in more detail below.

[0056] Fig. Figure 5 shows a schematic block diagram for the general explanation of influencing factors in determining the rotation angle φ between a rotor 102 and a stator 101, where only an example system with two pickup coils 115a, 115b is shown, and where the system provides an uncalibrated rotation angle signal phi'. The two pickup coils 115a, 115b of the pickup coil pair 115 can be, as previously described with reference to Fig. 3 discussed, arranged offset from each other and orthogonal pickup coil signals Si_PS1 , S i_PS2 , for example, sinusoidal and cosine-shaped induced pickup coil signals S i_PS1 = S i cos and S i_PS2 = S i generate the sin. The induction strength signal S that can be derived from it. i Then, as mentioned above, a combination of the two sine and cosine-shaped pickup coil signals S is used to generate S i_PS1 = S i cos, S i_PS2 = S i The sin of the pickup coil pair 115 is determined, whereby, for example, in the case of orthogonal signals, the following may apply: Si=Sicos2+Sisin2

[0057] The signal strength of the pickup coil signals S induced in pickup coils 115a, 115b i_PS1 = S i cos and S i_PS2 = S i The induction strength signal S can depend on several factors. iThe represented signal strength can depend, for example, on the actual rotation angle φ between the rotor 102 and the stator 101, i.e., on the actual relative position between the rotor 102 and the stator 101. Thus, for example, the amplitude and sign of the induction signal S can vary. i with changing position of the rotor 102 relative to the stator 101.

[0058] If both pickup coil signals S i_PS1 = S i cos and S i_PS2 = S i If the sines were perfectly orthogonal to each other and thus exhibited a perfect sine or cosine waveform, then the induction strength signal S would be i According to the formula above, it is independent of the rotation angle φ. However, if they deviate slightly from a perfect sine wave – as is usually the case in reality – then the induction signal S ionly be approximately constant with respect to the rotor position (actual rotation angle φ between rotor 102 and stator 101), i.e. S i It can exhibit small fluctuations. These fluctuations should be kept small so that the induction strength signal S is as low as possible. i reflects only the spatial distance 107 and preferably not the rotor position φ. To achieve this, both pickup coil signals S can be used. i_PS1 = S i cos and S i_PS2 = S i multiply sin by weighting factors, which in turn are suitable functions of the angle phi' (i.e., the rough estimate of the actual rotation angle φ).

[0059] That is, instead of the formula above [2], the signal strength, or the induction signal S representing the signal strength, can be used. i as follows from the two pickup coil signals S i_PS1 = S i cos and S i_PS2 = S i sin can be derived or determined: Si=(c(phi')∗Sicos)2+(s(phi')∗Sisin)2

[0060] Accordingly, for example, the pickup coil signals S can be used first. i_PS1 = S i cos and S i_PS2 = S i The values ​​of sine and sine can be multiplied by suitable weighting factors c(phi') and s(phi'). The intermediate results can then be squared and added together, and finally the square root can be taken.

[0061] Furthermore, the signal strength, or rather the induction strength signal S, can be i , depend on the electric current I1 flowing through the excitation resonant circuit 103 or through the excitation coil 104. The excitation resonant circuit 103 can, for example, power an oscillator 501 to generate a supply current I supplye.g., in the form of an alternating current signal. Furthermore, the excitation resonant circuit 103 can have a capacitance C1. The excitation coil 104 is represented as inductance L1. The magnitude of the supply current I supply The current I1 arriving at the excitation coil 104, however, depends, among other things, on the quality factor of the resonant circuit 103 and can therefore be determined by the supply current I. supply to an unknown extent. The signal strength of the induction signal S i The current I1 through the excitation coil 104 can decrease with decreasing current flow, or increase with increasing current flow I1 through the excitation coil 104.

[0062] The signal strength, or the induction signal S i , can also depend on the spatial distance 107 between the rotor 102 and the stator 101. For example, the signal strength or amplitude of the induction strength signal S can imonotonously with increasing spatial distance 107 fall.

[0063] Therefore, there can essentially be three factors that influence the signal strength, or the amplitude of the induction strength signal S. i , can influence, namely the current actual position of the rotor 102 relative to the stator 101, the current flow I1 through the excitation resonant circuit 103 or through the excitation coil 104 and the spatial distance 107 between the pickup coil arrangement 105 and the target arrangement 106. All three factors can initially be unknown.

[0064] In order to take into account the spatial distance 107 between the rotor 102 and the stator 101 when determining the calibrated rotation angle signal phi", the circuit 108 described herein is designed according to one embodiment to reduce or compensate for the position-related angular dependence, i.e., the dependence on the actual position between the rotor 102 and the stator 101. According to another embodiment, the circuit 108 is designed to reduce or compensate for the dependence on the current flow I1 through the excitation coil 104.

[0065] One embodiment can provide for reducing or compensating the position-related angular dependence as follows: • The pickup coil signals S generated in pickup coils 115a, 115b i_PS1 and S i_PS2can essentially change in a sinusoidal or cosine wave shape with varying actual rotation angle between rotor 102 and stator 101. • The pickup coil signals S i_PS1 and S i_PS2 can be essentially orthogonal to each other, i.e., phase-shifted by 90°. • Thus, circuit 108 can, for example, be designed to measure the induction strength signal S i to be determined as follows: ◯ S i = (c(phi')*Vcos 2 +s(phi')*Vsin 2 ) a , with for example: c = s = 1 and a = ½ or 1 (where Vcos is the voltage induced in the first pickup coil 115a, and Vsin is the voltage induced in the second pickup coil 115b) ◯ or: S i = cc(phi)*|Vcos|+ss(phi')*|Vsin| The calculation can be performed before or after demodulation from the carrier frequency to the baseband, although this may be simplified after demodulation has been performed. The functions c(phi'), s(phi'), cc(phi'), ss(phi') can be determined by measuring the voltages Vcos and Vsin for given pickup coils 115a, 115b with associated target arrangement 106. The circuit 108 can be configured to use the functions c(phi'), s(phi'), cc(phi'), ss(phi') to measure the inductive strength signal S i to then calculate and the angle dependence of the induction strength signal S i to minimize (e.g. by expanding the functions c(phi'), s(phi'), cc(phi'), ss(phi') into power series or Fourier series around phi' and subsequently determining the series coefficients by mathematical optimization methods) • The induction strength signal S generated in this way i In this case, this would correspond to an angle-corrected induction strength signal S i_St_korr , in which the position-related angle dependency is reduced or compensated, i.e. S i = S i_St_korrIn other words, based on the at least two phase-shifted pickup coil signals S i_PS1 = S i cos and S i_PS2 = S i sin (e.g. using a formula or a table) the induction strength signal S i can be derived, whereby the induction strength signal S i the angle-corrected induction strength signal S i_St_korr corresponds.

[0066] According to such an embodiment, the circuit 108 can therefore be designed to control the angular dependence of the induction strength signal S i to correct (e.g. to reduce or compensate) the current position of the rotor 102 relative to the stator 101 and generate a corresponding position-corrected induction strength signal S i_St_korr to determine, i.e. S i = S i_St_korr The circuit 108 can further be designed to measure the position-corrected induction strength signal S i = Si_St_korr to be used for signal processing and the calibrated rotation angle signal phi" based on the position-corrected induction strength signal S i = S i_St_korr and to determine it using the concept described herein. For example, the position-corrected induction strength signal S i = S i_St_korr as an input signal into the angle calculation unit 201 and / or into the distance determination unit 202 ( Fig. 2 and Fig. 4) be conducted.

[0067] The reduction or compensation mentioned above refers to the pickup coil signals S i_PS1 and S i_PS2 which are therefore not position-corrected. That is, pickup coils 115a and 115b deliver pickup coil signals S i_PS1 and S i_PS2 , which vary very strongly with the rotor rotational position φ – that is their main function. The induction strength signal S i Can S now be derived from these pickup coil signals?i_PS1 and S i_PS2 to be derived, with the aim that it varies significantly less depending on the rotor rotational position φ than the pickup coil signals S i_PS1 and S i_PS2 itself. That is, the pickup coil signals S i_PS1 and S i_PS2 are the reference, whereas the angular variation is reduced.

[0068] According to the invention, the circuit 108 is designed to reduce or compensate for the dependence on the current flow I1 through the excitation coil 104 as follows: a) According to a first embodiment, the circuit 108 is designed to measure the value of the current I1 flowing through the excitation coil 104, for example by means of an ammeter, and to subsequently feed the measured value of the electric current I1 into the signal processing. b) According to a second embodiment, the circuit 108 is designed to determine the current I1 flowing through the excitation coil 104 based on the supply current I supply to estimate, for example, if the Q-factor of the excitation resonant circuit is known, and a ratio S i / I1 to form. c) According to a third embodiment, the inductive angle sensor 100 has two pickup coil pairs 115, 125, each with an associated inductive target 106a, 106b, wherein each pickup coil pair 115, 125 has a different spatial distance to the corresponding target arrangement 106a, 106b. The first pickup coil pair 115, as mentioned above, has two individual pickup coils 115a, 115b. Each pickup coil 115a, 115b generates its own pickup coil signal S. i_PS1 , S i_PS2 Accordingly, the two pickup coil signals S i_PS1 , S i_PS2These signals are combined into a first pickup coil pair signal. From the first pickup coil pair signal S i_PS1 , S i_PS2 Then, in turn, a first coil pair induction strength signal S is generated. i_first derived according to the above formulas [2] or [3], which corresponds to the signal strength of the induction signals S generated in the first pickup coil pair 115a i_PS1 , S i_PS2 The second pickup coil pair 125 has two individual pickup coils 125a, 125b. Each pickup coil 125a, 125b generates its own pickup coil signal Si_ PS3 , S i_PS4 Accordingly, the two pickup coil signals S i_PS3 , S i_PS4 are combined as a second pickup coil pair signal. From the second pickup coil pair signal S i_PS1 , S i_PS2 Then a second coil pair induction strength signal S is generated. i_secondderived according to the above formulas [2] or [3], which corresponds to the signal strength of the induction signals S generated in the second pickup coil pair 125a i_PS3 , S i_PS4 The circuit 108 is designed according to the invention to measure the first coil pair inductance signal S. i_first with the second coil pair induction strength signal S i_second to put into perspective, e.g. according to S i_first / S i_second

[0069] An induction strength signal S generated in this way i In this case, this would correspond to a current-corrected induction signal S i_I1_korr , in which the dependence on the current I1 in the excitation coil 104 is relative to the original induction signal S i reduced or compensated.

[0070] According to such an embodiment, the circuit 108 can therefore be designed to reduce and / or compensate for the dependence on the current I1 in the excitation coil 104 and to generate a correspondingly current-corrected induction signal S i_I1-korr to determine. The circuit 108 can further be configured to use, instead of the uncorrected induction strength signal S i the current-corrected induction signal S i_I1_korr to be used for further signal processing and the calibrated rotation angle signal phi" based on the current-corrected induction strength signal S i_I1_korr to determine. For example, the current-corrected induction signal S i_I1_korr as an input signal into the angle calculation unit 201 and / or into the distance determination unit 202 ( Fig. 2 and Fig. 4) be conducted.

[0071] As mentioned above under point b), in one embodiment the circuit 108 can be configured to determine the current I1 flowing through the excitation coil 104 based on the supply current I supply to estimate. The induction strength signal S i As explained above, this depends, among other things, on the current I1 and the spatial distance 107 between the rotor 102 and the stator 101. To determine the initially unknown spatial distance 107 between the rotor 102 and the stator 101, the circuit 108 is designed according to the invention to measure the estimated current I1 and the measured induction signal S. i to put them in a relationship to each other, e.g. according to S i / I1. This ratio S i / I1 can then accordingly be a measure of the spatial distance 107 between the rotor 102 and the stator 101.

[0072] In an alternative embodiment, as mentioned above under point c), the spatial distance 107 between the rotor 102 and the stator 101 can be determined by means of two pickup coil pairs 115, 125. Fig. Figure 6A shows a schematic block diagram of an embodiment of an inductive angle sensor 100 with two pickup coil pairs 115, 125 for determining the spatial distance 107 between the rotor 102 and the stator 101.

[0073] In this embodiment according to the invention, the pickup coil arrangement 105 comprises a first pickup coil pair 115 and a second pickup coil pair 125. The first pickup coil pair 115 can essentially correspond to the pickup coil pair 115 discussed previously and may, for example, comprise a first pickup coil 115a and a second pickup coil 115b.

[0074] According to one conceivable embodiment, the numbering of the first pickup coil pair 115 and the second pickup coil pair 125, as well as the numbering of their respective targets 106a, 106b, can be different. For example, the pickup coils 115a, 115 of the first pickup coil pair 115 can have an n-fold numbering (e.g., n = 3), and the pickup coils 125a, 125b of the second pickup coil pair 125 can have an m-fold numbering, with m = n + x (e.g., m = 4).

[0075] For example, in the Fig. In the non-limiting embodiment shown in Figure 6A, the first target 106a, the first pickup coil 115a, and the second pickup coil 115b have a count of n = 3, and the second target 106b, the third pickup coil 125a, and the fourth pickup coil 125b could have a count of m = 4, i.e., L3, Lcos3, Lsin3 are three-count, and L4, Lcos4, Lsin4 are four-count. Thus, the three-count first target 106a (L3) does not couple a signal into the four-count second pickup coil pair 125 (Lcos4, Lsin4). Conversely, the four-count second target 106b (L4) does not couple into the three-count first pickup coil pair 115 (Lcos3, Lsin3). This makes it particularly easy to determine different signal strengths in the different pickup coil pairs 115, 126 (Lcos3,Lsin3 and Lcos4,Lsin4), from which the spatial distance 107 between the rotor 102 and the stator 101 can be determined.

[0076] It can be advantageous if at least the two pickup coil pairs 115, 125 (L3cos, L3sin, L4cos, L4sin), and optionally one or both targets 106a, 106 (L3, L4), are astatic. Coils or targets are described as astatic if homogeneous, time-varying magnetic fields do not induce signals in them. For further details on astatic embodiments, reference is made to the German patent specification with publication number DE 10 2019 213 174 B9.

[0077] The first and second pickup coils 115a, 115b of the first pickup coil pair 115 can be twisted relative to each other, so that a first pickup coil signal S induced in the first pickup coil 115a i_PS1 essentially orthogonal to a second pickup coil signal S induced in the second pickup coil 115b i_PS2 is, for example, according to S i_PS1 = S i cos and S i_PS2 = S isin. The first pickup coil signal S induced in the first pickup coil 115a i_PS1 It can, for example, exhibit a cosine waveform and is therefore in Fig. 6A, also designated c3. The second pickup coil signal S induced in the second pickup coil 115b. i_PS2 For example, it can have a sine waveform and is therefore in Fig. 6A is also referred to as s3.

[0078] A combination of the first and second pickup coil signals S induced in the two individual coils 115a, 115b of the first pickup coil pair 115 i_PS1 and S i_PS2 As described above, it delivers the first coil pair induction strength signal S i_first , which is the signal strength of the two pickup coil signals S induced in the first pickup coil pair 115 i_PS1 and S i_PS2 represented. Provided that the two pickup coil signals S i_PS1 and S i_PS2Since orthogonal signals are involved, the first coil pair induction strength signal S can be used. i_first for example from the two pickup coil signals S i_PS1 and S i_PS2 Calculated according to: Si_first=Si_PS12+Si_PS22 or Si_first=c32+s32.

[0079] The same applies analogously to the second pickup coil pair 125, which according to the invention has a third pickup coil 125a and a fourth pickup coil 125b. The third and fourth pickup coils 125a, 125b of the second pickup coil pair 125 can be twisted relative to each other, such that a third pickup coil signal S induced in the third pickup coil 125a i_PS3 essentially orthogonal to a fourth pickup coil signal S induced in the fourth pickup coil 125b i_PS4 is. The third pickup coil signal S induced in the third pickup coil 125a i_PS3 For example, it can exhibit a cosine waveform and is therefore in Fig. 6A, also designated c4. The fourth pickup coil signal S induced in the fourth pickup coil 125b. i_PS4 For example, it can have a sine waveform and is therefore in Fig. 6A is also referred to as s4.

[0080] According to the invention, a combination of the third and fourth pickup coil signals S induced in the two individual coils 125a, 125b of the second pickup coil pair 125 provides i_PS3 and S i_PS4 , as described above, the second coil pair induction strength signal S i_second , which is the signal strength of the two pickup coil signals S induced in the second pickup coil pair 125 i_PS3 and S i_PS4 represented. Provided that the two pickup coil signals S i_PS3 and S i_PS4 Since orthogonal signals are involved, the second coil pair induction strength signal S can be used. i_second for example from the two pickup coil signals S i_PS3 and S i_PS4 Calculated according to: Si_second=Si_PS32+Si_PS42 or Si_second=c42+s42.

[0081] Since the entire pickup coil arrangement 105 in this embodiment according to the invention comprises the two pickup coil pairs 115, 125 described above, the induction strength signal S is accordingly i from a suitable combination of the first coil pair induction strength signal S i_first and the induction strength signal of the second coil pair S i_second formed. That is, the first coil pair induction strength signal S i_first represents the induction strength in the first pickup coil pair 115, the second coil pair induction strength signal S i_second represents the induction strength in the second pickup coil pair 125, and the induction strength signal S i represents the induction strength of the entire pickup coil assembly 105.

[0082] The circuit 108 of the in Fig. The embodiment of an inductive angle sensor 100 shown in Figure 6A is designed to measure the two coil pair induction strength signals S mentioned above. i_first and S i_second to put the first and second pickup coil pairs 115, 125 into a relationship to each other, in the form S i_first / S i_second This ratio S i_first / S i_second depends monotonically on the spatial distance 107 between the rotor 102 and the stator 101 and is a measure of this spatial distance 107 ('AG') between the rotor 102 and the stator 101, for example: Si_first / Si_second−1∼1 / AG.

[0083] According to the invention, the spatial distance 107 between the rotor 102 and the stator 101 can thus be determined based on the two coil pair induction strength signals S i_first and S i_secondof the respective pickup coil pair 115, 125, or based on the induction strength signal S induced in the pickup coil arrangement 105 i , will be determined.

[0084] One advantage here is that the spatial distance 107 can be determined by forming the ratio between the two coil pair induction strength signals S i_first and S i_second The operation of the first and second pickup coil pairs 115, 125 can be independent of the electric current I1 flowing through the excitation resonant circuit 103 and the excitation coil 104, respectively. A further advantage can be the independence from the carrier frequency.

[0085] Furthermore, the first pickup coil pair 115 can have n-fold symmetry, and the second pickup coil pair 125 can have m-fold symmetry, for example with m = n + x, where m, n and x are integer variables.

[0086] According to the invention, the target arrangement 106, located in or on the rotor 102, comprises a first inductive target 106a and a second inductive target 106b. The first inductive target 106a can have n-fold symmetry, and the second inductive target 106b can have m-fold symmetry, for example with m = n + x, where m, n, and x are integer variables.

[0087] The first inductive target 106a with n-fold symmetry can thus be designed to transmit signals to the first pickup coil pair 115, which can also exhibit n-fold symmetry. The second inductive target 106b with m-fold symmetry, on the other hand, can be designed to transmit signals to the second pickup coil pair 125, which can also exhibit m-fold symmetry. This allows interference between the first and second pickup coil pairs 115 and 125 to be reduced or eliminated. For further details, reference is again made to the German patent specification with publication number DE 10 2019 213 174 B9.

[0088] As in Fig. As can be seen in Figure 6B, the two pickup coil pairs 115, 125 arranged in or on the stator 101 and the two associated inductive targets 106a, 106b arranged in or on the rotor 102 are arranged according to the invention along the common axis of rotation 109 such that the first pickup coil pair 115 has a first spatial distance 107a 'AG1' to the corresponding first inductive target 106a, and that the second pickup coil pair 125 has a second spatial distance 107b 'AG2' to the corresponding second inductive target 106b.

[0089] For example, the first spatial distance 107a can be smaller than the second spatial distance 107b. As mentioned above, the coil pair induction signal S belonging to the respective pickup coil pair 115, 125 is i_first or S i_secondamong other things, it depends on the spatial distance 107 of the rotor 102 relative to the stator 101. In the purely exemplary case mentioned here, the amplitude of the inductive strength signal S of the first coil pair belonging to the first pickup coil pair 115 could therefore be i_first due to the smaller distance 107a, it will be larger than the amplitude of the second coil pair inductance signal S belonging to the second pickup coil pair 125. i_second .

[0090] According to one conceivable embodiment, the inductive angle sensor 100 can be designed such that the two coil pair induction strength signals S i_first or S i_secondhave a clearly measurable difference in their respective amplitudes - if the difference becomes too small, noise and other real error terms lead in practice to an inaccurate estimation of the spatial distance 107 between rotor 102 and stator 101. On the other hand, the amplitudes of the two coil pair inductance signals S should i_first or S i_second The signal strengths should not differ too much from each other, as this can lead to noise problems for the weaker signal. Therefore, a trade-off must be found, which in practice can lie between signal strength ratios of 1.1 and 3 (e.g., between 1.5 and 2).

[0091] The distance between the two pickup coil pairs 115, 125 arranged in or on the stator 101 can always be known, since they can, for example, be mounted at a predetermined distance from each other. Likewise, the distance between the two inductive targets 106a, 106b arranged in or on the rotor 102 can always be known. Thus, the remaining variable is the spatial distance 107 between the rotor 102 and the stator 101, wherein, as previously described, this variable is determined according to the invention based on the ratio between the two coil pair induction strength signals S. i_first and S i_second of the respective pickup coil pair 115, 125 is determined.

[0092] Fig. Figure 7 shows a further embodiment of a circuit 108 for an inductive angle sensor 100 according to the innovative concept described herein. With this setup, a high-precision angle sensor 100 can be provided, whose accuracy in determining the actual rotation angle φ between the rotor 102 and the stator 101 is significantly increased compared to conventional angle sensors. This embodiment can utilize the so-called vernier scale principle for this purpose, which will be explained below with reference to Fig. 7 will be explained in more detail.

[0093] Initially, the stator 101 also exhibits similarity to the one in Fig. Figure 6A shows an embodiment of a pickup coil arrangement 105 with several pickup coils 115a, 115b, 125a, 125b and correspondingly several inductive targets (not shown). The pickup coil arrangement 105 has a first pickup coil pair 115 and a second pickup coil pair 125. The first pickup coil pair 115 has a first pickup coil 115a and a second pickup coil 115b. The second pickup coil pair 125 has a third pickup coil 125a and a fourth pickup coil 125b. The pickup coils 115a, 115b of the first pickup coil pair 115 can have n-fold symmetry, with e.g. n = 3, and the pickup coils 125a, 125b of the second pickup coil pair 125 can have m-fold symmetry, with e.g. m = 4.

[0094] The first pickup coil signal S is received in the first pickup coil 115a. i_PS1 induced, in the second pickup coil 115b the second pickup coil signal S i_PS2induced, in the third pickup coil 125a the third pickup coil signal S i_PS3 induced, and in the fourth pickup coil 125b the fourth pickup coil signal S i_PS4 induced.

[0095] A first signal processing unit 701 of the circuit 108 can be configured to process the first and second pickup coil signals S i_PS1 and S i_PS2 to combine and from this derive the first coil pair induction strength signal S i_first to generate the signal from the first pickup coil pair 115. A further signal processing unit 702 of the circuit 108 can be configured to process the third and fourth pickup coil signals S. i_PS3 and S i_PS4 to combine and from this derive the second coil pair induction strength signal S i_second to generate 125 from the second pickup coil pair.

[0096] Another signal processing unit 703 of the circuit 108 can be configured to process the two coil pair inductance signals Si_first and S i_second to put them in a relationship to each other. Since, as mentioned above, the ratio of the two coil pair induction strength signals S i_first and S i_second Since the spatial distance 107 (or Air Gap - 'AG') between the rotor 102 and the stator 101 is monotonically dependent, this spatial distance 107 ('AG') can be determined in a further signal processing unit 704 from the ratio S i_first / S i_second to be determined.

[0097] The determined spatial distance 107 between the rotor 102 and the stator 101 can be further processed in the form of a corresponding distance signal 204 and used in a further signal processing unit 705 to determine a first angle correction value dphi3' for the first pickup coil pair 115. The determined spatial distance 107, or the distance signal 204, can also be used in a further signal processing unit 706 to determine a second angle correction value dphi4' for the second pickup coil pair 125.

[0098] A first combiner 706 can be configured to combine the first angle correction value dphi3' with a first uncalibrated angle value phi3' of the first pickup coil pair 115, which was determined without taking into account the spatial distance 107 between the rotor 102 and the stator 101. According to the innovative concept described herein, this results in a first calibrated rotation angle value phi3" for the first pickup coil pair 115. Since this first calibrated rotation angle value phi3" applies only to the first pickup coil pair 115, but not yet to the entire pickup coil assembly 105, the first calibrated rotation angle value phi3" can also be referred to as a first calibrated intermediate rotation angle value phi3".

[0099] A second combiner 707 can be configured to combine the second angle correction value dphi4' with a second uncalibrated angle value phi4' of the second pickup coil pair 125, which was also determined without taking into account the spatial distance 107 between the rotor 102 and the stator 101. According to the innovative concept described herein, this results in a second calibrated rotation angle value phi4" for the second pickup coil pair 125. Since this second calibrated rotation angle value phi4" applies only to the second pickup coil pair 125, but not yet to the entire pickup coil assembly 105, the second calibrated rotation angle value phi4" can also be referred to as a second calibrated intermediate rotation angle value phi4".

[0100] A further signal processing unit 708 can be configured to combine the first calibrated intermediate rotation angle value phi3" and the second calibrated intermediate rotation angle value phi4" to generate a calibrated rotation angle value phi". The calibrated rotation angle value phi" can thus apply to the entire pickup coil assembly 105. The combination of the two calibrated intermediate rotation angle values ​​phi3" and phi4" can provide a more precise result compared to an embodiment in which the two calibrated intermediate rotation angle values ​​phi3" and phi4" are not combined.

[0101] For example, the signal processing unit 108 can combine the two calibrated intermediate rotation angle values ​​phi3" and phi4" according to the vernier principle. According to the vernier principle, one of the two calibrated intermediate rotation angle values ​​phi3" and phi4" can be used as a first, coarse scale for the actual rotation angle φ between the rotor 102 and the stator 101, and the other of the two calibrated intermediate rotation angle values ​​phi3" and phi4" can be used as a finer subdivision of the scale. This vernier principle is known, among other things, from calipers. For further details regarding the vernier principle for an inductive angle sensor 100, reference is again made to the German patent specification with publication number DE 10 2019 213 174 B9.

[0102] Fig.Figure 8 shows a schematic block diagram of a method 800 for determining the rotation angle φ between the stator 101 and the rotor 102 according to the concept described herein. For the implementation of the method 800, the stator 101 has the previously described excitation resonant circuit 103 or excitation coil 104 and the pickup coil arrangement 105, and the rotor 102 has the previously described inductive target arrangement 106.

[0103] In step 801, the excitation resonant circuit 103 is excited with an alternating current, so that an induced current is induced in the target arrangement 106, and the target arrangement 106 generates a magnetic field 116 in response to the induced current, which in turn generates induction signals S i_PS1 , S i_PS2 generated in the pickup coil arrangement 105.

[0104] In step 802, the signal strength of the induction signals S is determined. i_PS1 , S i_PS2 representing induction strength signal S i, as described above.

[0105] In step 803, the spatial distance 107 between the rotor 102 and the stator 101 is determined based on the induction strength signal S. i determined.

[0106] In summary, it can be said that the concept described herein relates, among other things, to a method 800 and a corresponding inductive angle sensor 100, wherein the spatial distance 107 between the stator 101 and the rotor 102 is determined based on an induction strength signal S i This determined spatial distance 107 can be used for further signal processing, for example for determining the rotation angle φ between the stator 101 and the rotor 102.

[0107] The inductive angle sensor 100 can, for example, comprise an excitation coil 104, pickup coils 115a, 115b, 125a, 125b, and inductive targets 106a, 106b. Furthermore, the inductive angle sensor 100 can comprise means configured to detect a signal strength of at least one coil pair signal S. i_PS1 , S i_PS2 to determine the signal strength induced in a pickup coil pair 115 (e.g., sine and cosine coils). This signal strength can be determined by an induction strength signal S. i or S i_first (i.e. S i = S i_first ) are represented, which consists of a suitable combination of the individual coil pair signals S i_PS1 , S i_PS2 can be determined. The inductive angle sensor 100 can also have means designed to measure this signal strength S. irelated to the signal strength of an electric current I1 flowing through the excitation coil 104. Alternatively or additionally, the inductive angle sensor 100 can have means designed to measure this signal strength S i = S i_first with signal strength S i_secondto relate a second pickup coil pair 125. The inductive angle sensor 100 can further comprise a circuit 108 configured to determine, e.g., estimate, the spatial distance 107 between the rotor 102 and the stator 101 and to generate a corresponding distance signal 204. The circuit 108 can further comprise an angle correction value dphi' based on the distance signal 204. The circuit 108 can further comprise a combiner 205 configured to combine a rough angle value phi' of the pickup coil pair 115, determined without considering the spatial distance 107, with the angle correction value dphi' to obtain a calibrated rotation angle signal phi". This can also be referred to as an autocalibration method for an inductive angle sensor 100.

[0108] The embodiments described above merely illustrate the principles of the concept described herein. It is understood that modifications and variations of the arrangements and details described herein will be obvious to other people skilled in the art. Therefore, it is intended that the concept described herein be limited only by the scope of protection of the following patent claims and not by the specific details presented herein by way of description and explanation of the embodiments.

[0109] Although some aspects have been described in connection with a device, it is understood that these aspects also constitute a description of the corresponding process, so that a block or component of a device can also be understood as a corresponding process step or as a feature of a process step. Similarly, aspects described in connection with or as a process step also constitute a description of a corresponding block, detail, or feature of a corresponding device.

[0110] Some or all of the process steps can be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or more of the key process steps can be performed by such an apparatus.

[0111] Depending on specific implementation requirements, embodiments of the concept described herein may be implemented in hardware or software, or at least partially in hardware or at least partially in software. The implementation may be carried out using a digital storage medium, such as a floppy disk, DVD, Blu-ray disc, CD, ROM, PROM, EPROM, EEPROM, FLASH memory, hard disk, or other magnetic or optical storage medium, on which electronically readable control signals are stored that can interact with, or interact with, a programmable computer system in such a way as to execute the respective method. Therefore, the digital storage medium may be computer-readable.

[0112] Some embodiments of the concept described herein therefore include a data carrier having electronically readable control signals capable of interacting with a programmable computer system to perform one of the methods described herein.

[0113] In general, embodiments of the concept described herein can be implemented as a computer program product with a program code, wherein the program code is effective in performing one of the procedures when the computer program product runs on a computer.

[0114] The program code can also be stored on a machine-readable medium, for example.

[0115] Other embodiments include a computer program for performing one of the methods described herein, wherein the computer program is stored on a machine-readable medium. In other words, an embodiment of the method described herein is a computer program that includes program code for performing one of the methods described herein when the computer program is executed on a computer.

[0116] Another embodiment of the method described herein is a data carrier (or a digital storage medium or a computer-readable medium) on which the computer program for carrying out one of the methods described herein is recorded. The data carrier, digital storage medium, or computer-readable medium is typically tangible and / or non-volatile.

[0117] Another embodiment of the method described herein is a data stream or a sequence of signals that represents the computer program for carrying out one of the methods described herein. The data stream or sequence of signals can be configured, for example, to be transferred via a data communication connection, such as the Internet.

[0118] Another embodiment comprises a processing device, for example a computer or a programmable logic device, which is configured or adapted to perform one of the methods described herein.

[0119] Another embodiment comprises a computer on which the computer program for performing one of the procedures described herein is installed.

[0120] Another embodiment of the concept described herein comprises a device or system designed to transmit a computer program for performing at least one of the methods described herein to a receiver. The transmission may be, for example, electronic or optical. The receiver may be, for example, a computer, a mobile device, a storage device, or a similar device. The device or system may, for example, include a file server for transmitting the computer program to the receiver.

[0121] In some embodiments, a programmable logic device (for example, a field-programmable gate array, an FPGA) can be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field-programmable gate array can interact with a microprocessor to perform one of the methods described herein. Generally, in some embodiments, the methods are performed by any hardware device. This can be general-purpose hardware such as a computer processor (CPU) or method-specific hardware such as an ASIC.

Claims

[1] Having an inductive angle sensor (100): a stator (101) with an excitation resonant circuit (103, 104) and a pickup coil arrangement (105), a rotor (102) rotatably arranged relative to the stator (101) with an inductive target arrangement (106), wherein the excitation resonant circuit (103, 104) can be excited with an alternating current in order to induce an induced current in the target arrangement (106), and wherein the target arrangement (106) is configured to generate a magnetic field (116) in response to the induced current, which in turn generates induction signals (S i_PS1 , S i_PS2 ) generated in the pickup coil arrangement (105), wherein the angle sensor (100) further comprises a circuit (108) which is configured to derive from a combination of the induction signals (S i_PS1 , S i_PS2 ) an induction strength signal (S i ) to derive the signal strength of the induction signals (S i_PS1 , S i_PS2) of the pickup coil arrangement (105) represents, and the spatial distance (107) between the rotor (102) and the stator (101) based on the induction strength signal (S i ) to determine and generate a corresponding distance signal (204), and wherein the circuit (108) is designed to measure the induction strength signal (S i ) with the current (I1) in the excitation resonant circuit (103, 104) into a ratio (S i / I1) to each other and based on this relationship (S i / I1) to determine the spatial distance (107) between the rotor (102) and the stator (101) and to output it as a corresponding distance signal (204). [2] Inductive angle sensor (100) according to claim 1, wherein the circuit (108) is configured to measure the value of the current (I1) flowing through the excitation coil (104) or based on the supply current (I supply to estimate. [3] Including an inductive angle sensor (100): a stator (101) with an excitation resonant circuit (103, 104) and a pickup coil arrangement (105), a rotor (102) rotatably arranged relative to the stator (101) with an inductive target arrangement (106), wherein the excitation resonant circuit (103, 104) can be excited with an alternating current in order to induce an induced current in the target arrangement (106), and wherein the target arrangement (106) is configured to generate a magnetic field (116) in response to the induced current, which in turn generates induction signals (S i_PS1 , S i_PS2 ) generated in the pickup coil arrangement (105), wherein the angle sensor (100) further comprises a circuit (108) which is configured to derive from a combination of the induction signals (S i_PS1 , S i_PS2 ) an induction strength signal (S i ) to derive the signal strength of the induction signals (S i_PS1 , S i_PS2) of the pickup coil arrangement (105) represents, and the spatial distance (107) between the rotor (102) and the stator (101) based on the induction strength signal (S i ) to determine and generate a corresponding distance signal (204), wherein the pickup coil arrangement (105) comprises a first pickup coil pair (115) with a first pickup coil (115a) and a second pickup coil (115b) and a second pickup coil pair (125) with a third pickup coil (125a) and a fourth pickup coil (125b), wherein the target arrangement (106) comprises a first inductive target (106a) and a second inductive target (106b), wherein the first pickup coil pair (115) has a first spatial distance (107a) to the first inductive target (106a), and wherein the second pickup coil pair (125) has a second spatial distance (107b) to the second inductive target (106b) that differs from the first spatial distance (107a), wherein the first pickup coil pair (115) provides a first pickup coil pair signal (S i_PS1 , S i_PS2 ) generated, from which a first coil pair induction strength signal (S i_first ) is derivable, and wherein the second pickup coil pair (125) provides a second pickup coil pair signal (S i_PS3 , S i_PS4 ) generated, from which a second coil pair induction strength signal (S) is generated. i_second ) is derivable, and wherein the circuit (108) is designed to generate the first coil pair inductance signal (S i_first) and the second coil pair induction strength signal (S i_se-cond ) to relate to each other (S i_first / S i_second ) and based on this ratio (S i_first / S i_second ) to determine the spatial distance (107) between the rotor (102) and the stator (101). [4] Inductive angle sensor (100) according to any one of claims 1 to 3, wherein the circuit (108) is configured to determine a calibrated rotation angle signal (phi") representing a rotation angle (φ) between the stator (101) and the rotor (102), wherein the calibrated rotation angle signal (phi") is based on the induction strength signal (S i ) and taking into account the distance signal (204) representing the spatial distance (107) between the rotor (102) and the stator (101). [5] Inductive angle sensor (100) according to claim 4, wherein the circuit (108) is further configured to determine an angle correction value (dphi') based on the distance signal (204) and to take the angle correction value (dph') into account when determining the calibrated rotation angle signal (phi"). [6] Inductive angle sensor (100) according to claim 5, wherein the circuit (108) is configured to determine an uncalibrated angle value (phi') which is determined independently of the spatial distance (107) between the rotor (102) and the stator (101), and wherein the circuit (108) is further configured to combine the uncalibrated angle value (phi') with the angle correction value (dphi') to determine the calibrated rotation angle signal (phi"). [7] Inductive angle sensor (100) according to one of claims 1 to 6, where the amplitude of the induction strength signal (S i) varies depending on the position of the rotor (102) relative to the stator (101), and wherein the circuit (108) is designed to reduce and / or compensate for this dependence and to generate a corresponding position-corrected induction strength signal (Si = S i_St_korr ) to determine, and wherein the circuit (108) is further configured to generate the calibrated rotation angle signal (phi") based on this position-corrected induction strength signal (S i = S i_St_korr ) to determine. [8] Inductive angle sensor (100) according to one of claims 1 to 7, where the amplitude of the induction strength signal (S i ) as a function of the current (I1) in the excitation resonant circuit (103, 104), and wherein the circuit (108) is designed to reduce and / or compensate for this dependence and to generate a correspondingly current-corrected induction signal (S i_I1_korr ) to determine, and wherein the circuit (108) is further configured to generate the calibrated rotation angle signal (phi") based on this current-corrected induction strength signal (S i_I1_korr ) to determine. [9] Inductive angle sensor (100) according to any one of claims 3 to 8, wherein the circuit (108) is designed to generate a distance signal (204) representing the spatial distance (107) between the rotor (102) and the stator (101), and based on this distance signal (204) to determine a first angle correction value (dphi3') for the first pickup coil pair (115) and a second angle correction value (dphi4') for the second pickup coil pair (125), and to take the first and second angle correction values ​​(dphi3', dphi4') into account when determining the calibrated rotation angle signal (phi"), wherein the circuit (108) is further configured to determine a first uncalibrated angle value (phi3') for the first pickup coil pair (115) and a second uncalibrated angle value (phi4') for the second pickup coil pair (125), wherein the uncalibrated angle values ​​(phi3', phi4') are determined independently of the spatial distance (107) between the rotor (102) and the stator (101), and wherein the circuit (108) is further configured to combine the first uncalibrated angle value (phi3') with the first angle correction value (dphi3') and to combine the second uncalibrated angle value (phi4') with the second angle correction value (dphi4') to determine the calibrated rotation angle signal (phi"). [10] Inductive angle sensor (100) according to claim 9, wherein the circuit (108) is designed to obtain a first calibrated intermediate rotation angle value (phi3'') when combining the first uncalibrated angle value (phi3') with the first angle correction value (dphi3'), and to obtain a second calibrated intermediate rotation angle value (phi4'') when combining the second uncalibrated angle value (phi4') with the second angle correction value (dphi4'), and wherein the circuit (108) is further configured to determine the calibrated rotation angle signal (phi") based on a combination of the first calibrated rotation angle intermediate value (phi3'') and the second calibrated rotation angle intermediate value (phi4''). [11] Inductive angle sensor (100) according to one of claims 3 to 10, wherein the first pickup coil (115a) is arranged offset from the second pickup coil (115b), such that a first pickup coil signal (S) induced in the first pickup coil (115a) i_PS1) is phase-shifted by 90° with respect to a second pickup coil signal induced in the second pickup coil (115b) (S i_PS2 ), and wherein the first coil-pair inductance signal (S i_first ), a combination of the first and second pickup coil signals (S i_PS1 , S i_PS2 ) exhibits. [12] Inductive angle sensor (100) according to one of claims 3 to 11, wherein the third pickup coil (125a) is arranged offset from the fourth pickup coil (125b), such that a third pickup coil signal (S) induced in the third pickup coil (125a) i_PS3 ) is phase-shifted by 90° with respect to a fourth pickup coil signal induced in the fourth pickup coil (125b) (S i_PS4 ), and wherein the second coil pair induction strength signal (S i_second ), a combination of the third and fourth pickup coil signals (S i_PS3 , S i_PS4 ) exhibits. [13] Inductive angle sensor (100) according to any one of claims 3 to 12, where the first pickup coil pair (115) has n-fold symmetry and the second pickup coil pair (125) has m-fold symmetry, with m = n + x, where m, n and x are integer variables, and wherein the first inductive target (106a) has n-fold symmetry and the second inductive target (106b) has m-fold symmetry, with m = n + x, where m, n and x are integer variables. [14] Method (800) for operating an inductive angle sensor (100) with a stator (101) and a rotor (102) movable relative to the stator (101), wherein the stator (101) has an excitation resonant circuit (103, 104) and a pickup coil arrangement (105), and wherein the rotor (102) has an inductive target arrangement (106), wherein the method (800) comprises the following steps: Excitation of the excitation resonant circuit (103, 104) with an alternating current, so that an induced current is induced in the target arrangement (106) and the target arrangement (106) generates a magnetic field (116) in response to the induced current, which in turn induces signals (S i_PS1 , S i_PS2 ) generated in the pickup coil arrangement (105), Determining the signal strength of the induction signals (S i_PS1 , S i_PS2 ) representing induction strength signal (S i ), and Determining a spatial distance (107) between the rotor (102) and the stator (101) based on the induction strength signal (S i ), by the induction strength signal (S i ) with the current (I1) in the excitation resonant circuit (103, 104) into a ratio (S i / I1) is set to each other and based on this ratio (S i / I1) the spatial distance (107) between the rotor (102) and the stator (101) is determined and output as a corresponding distance signal (204). [15] Method (800) for operating an inductive angle sensor (100) with a stator (101) and a rotor (102) movable relative to the stator (101), wherein the stator (101) has an excitation resonant circuit (103, 104) and a pickup coil arrangement (105), and wherein the rotor (102) has an inductive target arrangement (106), wherein the method (800) comprises the following steps: Excitation of the excitation resonant circuit (103, 104) with an alternating current, so that an induced current is induced in the target arrangement (106) and the target arrangement (106) generates a magnetic field (116) in response to the induced current, which in turn induces signals (S i_PS1 , S i_PS2 ) generated in the pickup coil arrangement (105), Determining the signal strength of the induction signals (S i_PS1, S i_PS2 ) representing induction strength signal (S i ), and Determining a spatial distance (107) between the rotor (102) and the stator (101) based on the induction strength signal (S i ), wherein the pickup coil arrangement (105) comprises a first pickup coil pair (115) with a first pickup coil (115a) and a second pickup coil (115b) and a second pickup coil pair (125) with a third pickup coil (125a) and a fourth pickup coil (125b), wherein the target arrangement (106) comprises a first inductive target (106a) and a second inductive target (106b), wherein the first pickup coil pair (115) has a first spatial distance (107a) to the first inductive target (106a), and wherein the second pickup coil pair (125) has a second spatial distance (107b) to the second inductive target (106b) that differs from the first spatial distance (107a), where a first pickup coil pair signal (S i_PS1 , S i_PS2 ) of the first pickup coil pair (115) is determined and from this a first coil pair inductance signal (S) is derived. i_first ) is derived, and wherein a second pickup coil pair signal (S i_PS3 , S i_PS4 ) of the second pickup coil pair (125) is determined and a second coil pair inductance signal (S) is derived from it. i_second ) is derived, and the method further includes the fact that the first coil pair induction strength signal (S i_first ) and the second coil pair induction strength signal (S i_second ) are put into a relationship with each other (S i_first / S i_second ) and based on this ratio (S i_first / S i_second ) the spatial distance (107) between the rotor (102) and the stator (101) is determined. [16] Computer-readable digital storage medium with program code for carrying out the method according to claim 14 or 15, when the program runs on a computer.

Images