Abstract
An inductive sensor arrangement includes at least two coupling devices rotatable about an axis of rotation at a different speed than a rotatable body, and at least one measured value acquisition device, which includes a multilayered circuit carrier having at least one exciter structure and at least two receiving structures, each of which is associated with one of the coupling devices. The exciter structure is coupled to at least one oscillator circuit, which generates a periodic change signal in the exciter structure. The coupling devices are designed to affect an inductive coupling between the exciter structure and the associated receiving structure. At least two receiving structures are arranged concentrically on the circuit carrier without significant overlap. An evaluation and control unit is designed to evaluate signals induced in the receiving structures, provided as at least two different measurement signals, which represent information about the rotational movement of the body.
Claims
1. An inductive sensor arrangement for detecting a rotational movement of a body rotatable about an axis of rotation, comprising: at least two coupling devices rotatable about the axis of rotation; and at least one measured value acquisition device having a multilayered circuit carrier comprising: at least one exciter structure coupled to at least one oscillator circuit, which, during operation, comprises at least one periodic change signal in the at least one exciter structure; and at least two receiving structures, each receiving structure of the at least two receiving structures being respectively associated with one of the at least two coupling devices, which is configured inductively couple the at least one exciter structure with the respectively associated receiving structure, wherein at least two of the receiving structures of the at least two receiving structures are arranged concentrically on the circuit carrier, without significant overlap; at least one transmission device configured to transfer rotational movement of the rotatable body about the axis of rotation with a predetermined transmission ratio coaxially to at least a first coupling device of the at least two coupling devices, such that the first coupling device rotates at a different speed about the axis of rotation than the rotatable body; and at least one evaluation and control unit configured to evaluate signals induced in the at least two receiving structures, which are provided by the at least two receiving structures as at least two different measurement signals, the at least two different measurement signals representing information about the rotational movement of the body.
2. The inductive sensor arrangement according to claim 1, wherein the at least one exciter structure and the at least two receiving structures are arranged concentrically.
3. The inductive sensor arrangement according to claim 2, wherein the at least one exciter structure and the at least two receiving structures are arranged concentrically on the circuit carrier without significant overlap.
4. The inductive sensor arrangement according to claim 3, wherein: at least one first receiving structure of the at least two receiving structures, which is associated with the first coupling device, is arranged radially outside the at least one exciter structure on the circuit carrier, and at least one second receiving structure of the at least two receiving structures is arranged radially within the at least one exciter structure on the circuit carrier.
5. The inductive sensor arrangement according to claim 1, wherein the at least one transmission device is configured as a planetary gear train or as a gear system.
6. The inductive sensor arrangement according to claim 1, wherein the at least two coupling devices each have a number of electrically conductive coupling segments that define a periodicity of the signals induced in the at least two receiving structures.
7. The inductive sensor arrangement according to claim 6, wherein the first coupling device is configured as a tooth disk and faces a first side of the circuit carrier, and the electrically conductive coupling segments are configured as teeth and are separated from one another by recesses.
8. The inductive sensor arrangement according to claim 7, wherein the electrically conductive coupling segments of the first coupling device are connected to each other via an internal short-circuit ring or via an external short-circuit ring.
9. The inductive sensor arrangement according to claim 8, wherein at least one radial slot is arranged in the electrically conductive coupling segments of the first coupling device so as to separate the internal short-circuit ring or the external short-circuit ring.
10. The inductive sensor arrangement according to claim 6, wherein: a second coupling device of the at least two coupling devices and a third coupling device of the at least two coupling devices are each configured as a rotor with electrically conductive coupling segments configured designed as blades, the number of electrically conductive coupling elements of the second and third coupling devices differs, and the second coupling device faces a first side of the circuit carrier and the third coupling device faces a second side of the circuit carrier.
11. The inductive sensor arrangement according to claim 10, wherein the respective receiving structures associated with the second and third coupling devices are arranged in a plurality of different layers of the circuit carrier, and at least partially overlap one another.
12. The inductive sensor arrangement according to claim 1, wherein the at least two receiving structures comprise at least one receiver coil having a periodically repeating loop structure.
13. The inductive sensor arrangement according to claim 12, wherein: a first receiver coil of the at least one receiver coil forms a sine channel and a second receiver coil of the at least one receiver coil forms a cosine channel, the at least two measurement signals each comprise a signal of the sine channel and a signal of the cosine channel, and the at least one evaluation and control unit is configured to determine corresponding information of the rotational movement of the body using an arctangent function.
14. The inductive sensor arrangement according to claim 1, wherein: each of the at least two receiving structures comprises at least three receiver coils having a periodically repeating loop structure that form a multi-phase system, the at least one evaluation and control unit is configured to execute a suitable phase transformation of signals of the multi-phase system and, via an arctangent function, to determine the at least two measurement signals.
15. The inductive sensor arrangement according to claim 1, wherein the at least one evaluation and control unit is configured to determine a differential angle between a first portion of the rotatable body and a second portion of the rotatable body and/or an absolute rotational angle of the rotatable body from the at least two different measurement signals.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 shows a schematic illustration of a first exemplary embodiment of an inductive sensor arrangement according to the disclosure.
[0024] FIG. 2 shows a schematic plan view of the sensor unit according to the disclosure from FIG. 1 with a circuit carrier shown in a transparent manner.
[0025] FIG. 3 shows a schematic plan view of a second exemplary embodiment of a sensor unit according to the disclosure with a circuit carrier shown in a transparent manner.
[0026] FIG. 4 shows a schematic block diagram of an exemplary embodiment of an evaluation and control unit for the inductive sensor arrangements according to the disclosure from FIGS. 1 to 3.
DETAILED DESCRIPTION
[0027] As can be seen from FIGS. 1-4, the illustrated exemplary embodiments comprise an inductive sensor arrangement 1, 1A, 1B according to the disclosure, for detecting a rotational movement of a body 3 rotatable about an axis of rotation DA, each of at least two coupling devices 5 rotatable about the axis of rotation DA, 5A1, 5A1, 5B, 5C and at least one measured value acquisition device 10, which comprises a multilayered circuit carrier 7 having at least one exciter structure 12, 12A, 12B and at least two receiving structures 14, 14A, 14B, 14C, which are associated with one of the at least two coupling devices 5, 5A1, 5A1, 5B, 5C. The at least one exciter structure 12, 12A, 12B is coupled to at least one oscillator circuit 26 which, during operation, couples a periodic alternating signal WS1, WS2 into the at least one exciter structure 12, 12A, 12B. The at least two coupling devices 5, 5A1, 5A1, 5B, 5C each affect an inductive coupling between the at least one exciter structure 12, 12A, 12B and the associated receiving structure 14, 14A, 14B, 14C. At least one transmission device 30 coaxially transfers the rotational movement of the rotatable body 3 about the axis of rotation DA with a predetermined transmission ratio to at least a first coupling device 5A1, 5A2 of the at least two coupling devices 5 such that at least the first coupling device 5A1, 5A2 rotates at a different rotational speed about the axis of rotation DA than the rotatable body 3. At least two of the receiving structures 14, 14A, 14B, 14C of the at least two receiving structures 14, 14A, 14B, 14C are arranged concentrically on the circuit carrier 7 without significant overlap. At least one evaluation and control unit 20 evaluates signals induced in the at least two receiving structures 14, 14A, 14B, 14C, which provide the at least two receiving structures 14, 14A, 14B, 14C as at least two different measurement signals MS1, MS2, MS3 representing information about the rotational movement of the body 3.
[0028] As can further be seen from FIGS. 1 to 3, the inductive sensor arrangement 1, 1A, 1B according to the disclosure in the illustrated exemplary embodiments comprises three receiving structures 14A, 14B, 14C and three coupling devices 5A1, 5A1, 5B, 5C and an evaluation and control unit 20. Here, a first receiving structure 14A is associated with a first coupling device 5A1, 5A1 and is arranged on a first side 7.1, here the bottom of the circuit carrier 7. A second receiving structure 14B is associated with a second coupling device 5B and is also arranged on the first side 7.1 of the circuit carrier 7. A third receiving structure 14C is associated with a third coupling device 5C and is also arranged on the second side 7.2 of the circuit carrier 7. As is further visible from FIGS. 1-3, a first exciter structure 12A is arranged on the first side 7.1 of the circuit carrier 7 and faces the first coupling device 5A1, 5A1 and the second coupling device 5B. A second exciter structure 12B is arranged on the second side 7.2 of the circuit carrier 7 and faces the third coupling device 5C. Thus, the first side 7.1 of the circuit carrier 7 faces the first coupling device 5A1, 5A1 and the second coupling device 5B, while the second side 7.2 of the circuit carrier 7 faces the third coupling device 5C. Also, the second coupling device 5B and the third coupling device 5C are directly connected to the rotatable body 3 designed as a torsion rod 3A. This means that the rotational movement of the torsion rod 3A corresponds to the rotational movements of the second coupling device 5B and the third coupling device 5C. The first coupling device 5A1, 5A1 is connected to the torsion rod 3A via the transmission device 30. Thus, the rotational movement of the first coupling device 5A1, 5A2 is transmitted or reduced as a function of the transmission ratio of the transmission device 30 to the rotational movement of the rotatable body 3 designed as a torsion rod 3A.
[0029] As can be further seen from FIGS. 1 to 3, the exciter structures 12 each comprise at least one exciter coil. In the illustrated exemplary embodiments, the receiving structures 14, 14A, 14B, 14C each have two receiver coils each having a periodically repeating loop structures. Here, a first receiver coil of the receiving structures 14, 14A, 14B, 14C each forms a sine channel and a second receiver coil of the receiving structures 14, 14A, 14B, 14C each forms a cosine channel. Thus, the corresponding measurement signals MS1, MS2, MS3 each comprise a signal of the sine channel and a signal of the cosine channel. The evaluation and control unit determines, by an arctangent function, corresponding information of the rotational movement of the body 3. To avoid crossovers of the loop structures of the individual receiving structures 14, 14A, 14B, 14C, portions of the loop structures are arranged in a plurality of different layers of the circuit carrier 7. The individual portions of the respective loop structure are electrically connected to each other via vias not shown in greater detail.
[0030] In an alternative embodiment of the inductive sensor arrangement 1, which is not shown, the receiving structures 14, 14A, 14B, 14C comprise at least three receiver coils having a periodically repeating loop structure, which form a multi-phase system. The at least one evaluation and control unit 20 carries out a suitable phase transformation of signals of the multi-phase system, and determines the respective measurement signal MS1, MS2, MS3 using an arctangent function.
[0031] As can further be seen from FIGS. 2 and 3, the first exciter structure 12A and the first receiving structure 14A and the second receiving structure 14B are arranged concentrically on the first side 7.1 of the circuit carrier 7 without significant overlap. Here, the first receiving structure 14A associated with the first coupling device 5A1, 5A2 is arranged radially outside of the first exciter structure 12A. The second receiving structure 14B associated with the second coupling device 5B is radially within the first exciter structure 12A. In addition, the second exciter structure 12B and the third receiving structure 14C are arranged concentrically on the second side 7.2 of the circuit carrier 7 without significant overlap. Here, the third receiving structure 14C associated with the third coupling device 5C is arranged radially within the second exciter structure 12B.
[0032] As can be further seen from FIGS. 1 to 3, the second receiving structure 14B associated with the second coupling device 5B and the third receiving structures 14C associated with the third coupling device 5C are arranged in a plurality of different layers of the circuit carrier 7 and at least partially overlap each other.
[0033] As can further be seen from FIGS. 1-3, the coupling devices 5, 5A1, 5A2, 5B, 5C each have a predetermined number of electrically conductive coupling segments 5.1, 5.1A, 5.1B, 5.1C defining a periodicity of the signals induced in the receiving structures 14, 14A, 14B, 14C. In the illustrated exemplary embodiments, the first coupling device 5A1, 5A1 has fifteen electrically conductive coupling segments 5.1A as an example. The second coupling device 5B comprises four electrically conductive coupling segments 5.1B and the third coupling device 5C comprises seven electrically conductive coupling segments 5.1C.
[0034] As can be seen further from FIGS. 1 and 2, the first coupling device 5A1 in the illustrated first exemplary embodiment of the inductive sensor arrangement 1A is designed as a toothed disk and faces the first side 7.1 of the circuit carrier 7. The electrically conductive coupling segments are designed as teeth and separated from one another by recesses. Here, the electrically conductive coupling segments 5.1A of the first coupling device 5A1 are connected to each other via an outer short-circuit ring 5.2B. In an alternative embodiment of the inductive sensor arrangement 1, not shown, at least one radial slot is introduced into the electrically conductive coupling segments 5.1A of the first coupling device 5A1, which separates the outer short-circuit ring 5.2B.
[0035] As can be seen further from FIGS. 3, the first coupling device 5A2 in the illustrated second exemplary embodiment of the inductive sensor arrangement 1B is also designed as a toothed disk and faces the first side 7.1 of the circuit carrier 7. In contrast to the first exemplary embodiment, the electrically conductive coupling segments 5.1A, which are designed as teeth, are connected to each other in the second exemplary embodiment of the inductive sensor arrangement 1B via an internal short-circuit ring 5.2A. In an alternative embodiment of the inductive sensor arrangement 1, not shown, at least one radial slot is introduced into the electrically conductive coupling segments 5.1A of the first coupling device 5A2, which separates the internal short-circuit ring 5.2A.
[0036] As can be further seen from FIGS. 1-3, the second coupling device 5B and the third coupling device 5C are each designed as rotors with electrically conductive coupling segments 5.1B, 5.1C configured as blades, wherein the number of electrically conductive coupling elements 5.1B, 5.1C of the two coupling devices 5B, 5C differs.
[0037] In the illustrated exemplary embodiments of the inductive sensor arrangement 1, 1A, 1B, the transmission device 30 is designed as a planetary gear train 30A. In an alternative embodiment not shown, the transmission device is used as a gear system or gear train.
[0038] As can further be seen from FIG. 4, an oscillator circuit 28 arranged in the evaluation and control unit 20 generates two periodic change signals WS1, WS2. In the illustrated exemplary embodiment, a first change signal WS1 is coupled to the first exciter structure 12A and a second change signal WS2 is coupled to the second exciter structure 12B. In addition, the evaluation and control unit 20 receives a first measurement signal from the first receiving structure 14A, a second measurement signal MS2 from the second receiving structure 14B, and a third measurement signal MS3 from the third receiving structures 14C. A signal processing block 22 multiplexes and demodulates the measurement signals MS1, MS2, MS3 and generates corresponding analog rotational angle signals DW1, DW2, DW3, which are subsequently digitized by an analog-digital converter 24 and passed to a logic block 26. In this case, a first rotational angle signal DW1 represents the first measurement signal MS1, a second rotational angle signal DW2 represents a second measurement signal MS2 and a third rotational angle signal DW3 represents a third measurement signal MS3. From the first rotational angle signal DW1 and the second rotational angle signal DW2, the logic block 26 of the evaluation and control unit 20 determines an absolute rotational angle of the rotatable body 3 in a range of uniqueness that is greater than 360 degrees or a revolution of the rotatable body 3, respectively. From the second rotational angle signal DW2 and the third rotational angle signal DW3, the logic block 26 of the evaluation and control unit 20 determines a differential angle between a first portion of the rotatable body 3 and a second portion of the rotatable body 3. From this differential angle, a torque may be determined acting on the rotatable body 3 designed as torsion rod 3A.
