Inductive position sensor device, drive device

Abstract

The invention relates to an inductive position sensor device (5) for detecting the position of a coupling element, which can be arranged on a movable actuator element of an electric machine (2), having at least one transmitter coil (8, 8') for generating electromagnetic waves, at least one receiver coil (9, 9') for detecting electromagnetic waves generated by the transmitter coil (8) and influenced by the actuator element, and a computing unit (11) for operating the transmitter coil (8) and evaluating the electromagnetic waves detected by the receiver coil (9, 9') in order to determine the position, the coils (8, 9) being arranged on the front side of a common circuit board (6) and the computing unit (11) being arranged on the back side, the coils (8, 8', 9, 9') and the computing unit (11) being electrically connected by connection lines (12, 13) which extend along the circuit board (6) and through the circuit board (6). It is provided that the connection lines (12, 13) are essentially parallel to one another.

Description

Technical Field

[0001] This invention relates to an inductive position sensor device for detecting the position of a coupling element that can be arranged on a movable actuator element of a motor. The position sensor device has a transmitter coil for generating electromagnetic waves, at least one receiver coil, and a computing unit. The receiver coil is used to detect the electromagnetic waves generated by the transmitter coil and affected by the coupling element. The computing unit is used to manipulate the transmitter coil and evaluate the electromagnetic waves detected by the receiver coil to determine the position of the actuator element. The coil and the computing unit are arranged on a common circuit board, with the coil arranged on the front side of the circuit board and the computing unit arranged on the back side of the circuit board opposite to the front side. The coil and the computing unit are electrically connected by a connecting line extending along and through the circuit board.

[0002] Furthermore, the present invention relates to a drive device, particularly for braking devices of motor vehicles, the drive device having a motor and an inductive position sensor device associated with the motor for detecting the position of a movable actuator element of the motor, the actuator element being particularly a rotor actuator or a linear actuator. Background Technology

[0003] Inductive position sensor devices, particularly in the form of rotor orientation sensor devices, are known in the prior art for detecting the azimuth or angular position of a motor's rotor. These position sensor devices utilize the effect that, depending on the angular orientation of a coupling element, specifically fixed to the end face of the rotor, the electromagnetic wave field exposed to the transmitter coil is affected in an understandable manner. To manipulate the transmitter coil and evaluate the results detected by the receiver coil, such sensor devices typically also have a control unit or computing unit, for example, in the form of a microprocessor or application-specific integrated circuit (ASIC). The computing unit is specifically used here to manipulate the transmitter coil to generate a modulated signal. The signal received by the receiver coil is then demodulated by the computing unit or optionally by another computing unit so that the signal can be evaluated and thus affected by the rotor of the motor. Electromagnetic waves are thus coupled from the transmitter coil to the coupling element and from the coupling element to the receiver coil, allowing the rotor angular orientation to be extracted from the electromagnetic signal detected by the receiver coil.

[0004] Typically, the computing unit and at least two coils, namely the transmitter coil and the receiver coil, are arranged on the same circuit board to enable simple electrical and / or signal connections between the computing unit and the coils, and to achieve a compact configuration. Summary of the Invention

[0005] The position sensor device according to the invention, having the features of claim 1, has the advantage of enabling the circuit board to be manufactured less cumbersomely and at a lower cost than to date, because in particular, so-called shielding or shielding layers can be eliminated. To date, these shielding or shielding layers have been used to interrupt or limit electromagnetic interference fields between different layers of the circuit board. However, with the position sensor device according to the invention, such electromagnetic interference signals or interference fields are suppressed or at least reduced from the outset to the point that additional shielding layers can be eliminated. This, in particular, reduces the number of stacks or layers of the circuit board. According to the invention, this is achieved by making the connecting lines that connect the computing unit to the coil extend at least substantially parallel to each other. By extending them parallel, induction in the area of ​​the connecting lines is minimized, thereby preventing offsets in the output signal and thus optimizing the measurement results. Furthermore, the connecting lines are preferably designed to be as short as possible.

[0006] According to a preferred embodiment of the invention, the connecting lines extend at least partially parallel to each other on different layers of the circuit board. Therefore, in this case, the connecting lines are not located on the same layer of the circuit board, but are spaced apart by the layers of the circuit board. This orientation on different layers ensures a particularly compact construction of the circuit board and provides the possibility that the connecting lines can also be formed directly overlapping each other on the circuit board and thus very close to each other.

[0007] Furthermore, it is preferably specified that the connecting lines on different layers extend parallel to each other, at least partially overlapping each other. If the circuit board is designed as a circle or ring, such as in the case of a rotor orientation sensor, then the connecting lines extending parallel to each other along the axial direction overlap each other directly along the axial direction. This achieves a particularly compact construction and advantageously reduces electromagnetic control effects.

[0008] According to an alternative embodiment of the invention, the connecting lines, or at least two of the connecting lines, extend substantially parallel to each other on the circuit board layer. Thus, the connecting lines do not overlap, but are arranged side-by-side on the circuit board, more precisely, on the circuit board layer. This also advantageously reduces electromagnetic control effects, wherein the layer arrangement can be implemented cost-effectively if necessary.

[0009] Furthermore, preferably, the circuit board has a first layer (or first layer), a second layer (or second layer), a third layer (or third layer), and a fourth layer (or fourth layer) overlapping each other, wherein at least one coil of the coils is arranged at least partially on the first and second layers, the computing unit is arranged on the fourth layer, and parallel-extending segments of connecting lines are arranged at least on the third and / or fourth layers. Thus, the circuit board is designed as four-layered or having four layers, wherein preferably the coils are located on two layers and the computing unit and connecting lines, more precisely at least the parallel-extending segments of the connecting lines, are located on the remaining two layers. This ensures advantageous separation of functions in the sensor device, which allows for cost-effective manufacture of a circuit board with components arranged thereon. Laying or arranging parallel-extending segments of connecting lines on the third and / or fourth layers provides the advantage of being able to position the connecting lines independently of the coil extensions, thereby allowing for optimal implementation of the connecting line routing.

[0010] Furthermore, it is preferably specified that the position sensor device has at least one transmitter coil and at least two receiver coils, wherein the receiver coils are arranged, in particular, staggered from each other, on the actuator element. This results in high-resolution and clear signals being received, and the position of the actuator element being precisely and, in particular, absolutely determined.

[0011] Furthermore, it is preferably specified that the corresponding receiver coil extends at least on the first and second layers. Thus, the receiver coil extends on the two uppermost layers of the circuit board, thereby ensuring a favorable coil routing, in which segments of the same coil can be intersected by being arranged on different layers.

[0012] Furthermore, it is preferably specified that the at least one transmitter coil extends only on the first layer or extends at least on the first and second layers.

[0013] Particularly preferably, the circuit board has no shielding layer, and therefore no intermediate layer, particularly made of copper, to prevent electromagnetic interference fields or signals from transitioning to the next layer. Since the position sensor device is designed according to the invention, such a shielding layer is not necessary and is therefore preferably avoided in the present case. This significantly reduces the manufacturing cost, particularly of the circuit board.

[0014] Particularly preferably, the circuit board is constructed in a disc shape, particularly an annular disc shape or a strip shape, depending on whether the position sensor device is constructed as a rotor orientation sensor device or a linear actuator orientation sensor device.

[0015] In addition, it is preferably specified that at least one EMV anti-interference capacitor, preferably multiple EMV anti-interference capacitors, are also arranged on the back of the circuit board to improve the EMV compatibility of the position sensor device.

[0016] The drive device according to the invention, having the features of claim 12, is characterized by the position sensor device according to the invention. This brings the advantages already mentioned. Attached Figure Description

[0017] In particular, additional advantages and preferred features and combinations thereof arise from the foregoing description and the claims. The invention will now be further explained with reference to the accompanying drawings. Wherein:

[0018] Figure 1 The advantageous drive mechanism is illustrated in a simplified diagram;

[0019] Figure 2 The advantageous position sensor device of the drive unit is shown in a top view;

[0020] Figure 3 A simplified illustration of the position sensor device is shown in the side view.

[0021] Figure 4 An enlarged detailed view of the position sensor device according to the first embodiment is shown; and

[0022] Figure 5 An enlarged detailed view of the position sensor device according to the second embodiment is shown. Detailed Implementation

[0023] Figure 1 A simplified illustration shows a drive unit 1 advantageous for a consumable device (not shown further here), such as the braking system of a motor vehicle, particularly a parking brake. The drive unit 1 has a motor 2 with a drive shaft 3 rotatably supported in a housing (not shown) and carrying a rotor 4 associated with a stator 4' fixed relative to the housing. The drive shaft 3 is mechanically coupled to, or can be coupled to, the consumable device to drive it.

[0024] The rotor 4 of motor 2 is associated with a position sensor device 5, currently in the form of a rotor orientation sensor device, which detects the rotor angular orientation of rotor 4 by sensing. For this purpose, the position sensor device 5 has a circuit board 6, which, according to the current embodiment, is annular and arranged coaxially with the drive shaft 3 and associated with the end face of rotor 4. The circuit board 6 carries at least one transmitter coil 8 and at least two receiver coils 9, 9' on its front side 7 facing rotor 4. A computing unit 11 is arranged on the back side 10 of the circuit board 6 opposite rotor 4; according to the current embodiment, this computing unit is an application-specific integrated circuit (ASIC) and is electrically connected to the two types of coils 8, 9, 9'. Specifically, the coils 8, 9, 9' are printed on the circuit board 6, particularly on different layers of the circuit board 6, as will be explained further below. Figure 1 In the illustration, coils 8, 9, and 9' are shown as blocks in a very simplified manner. Preferably, at least one EMV anti-interference capacitor 14 is also arranged on the back side 10 and is specifically electrically connected to the computing unit 11 and / or coils 8, 9, and 9'.

[0025] The calculation unit 11 controls the transmitter coil 7 to emit signals via electromagnetic waves. These signals penetrate the coupling element 15 of the position sensor device 5, which is arranged on the end face of the rotor 4 and faces the circuit board 6. The electromagnetic waves are affected by the coupling element 15 and are reflected or conducted to the receiver coil 9, where the influence on the electromagnetic waves depends on the coupling element 15, more precisely, the rotational angular position of the rotor 4. The calculation unit 11 demodulates the signal detected by the receiver coil 9 and affected by the rotor 4, and determines the rotor angular position of the rotor 4 based on the detected signal. The method of determining the rotor angular orientation using an inductive rotor position sensor device (also commonly referred to as an inductive rotor orientation sensor) is basically known, therefore the specific function and implementation of this method will not be discussed here.

[0026] Figure 2 A simplified top view shows the position sensor device 5. The circuit board 6 is annular, as already mentioned. Coils 8 and 9 overlap each other on different layers of the circuit board 6, such that these coils... Figure 2 The top view shown intersects at multiple locations. The computing unit 11 is located behind the coils 8 and 9, so that the coils 8 and 9 are above the computing unit 11 in the top view. Therefore, the computing unit 11 and the coils 8 and 9 are not only arranged on different sides of the circuit board 6, but are also arranged to directly overlap each other, thereby ensuring a particularly compact configuration with a very short connection path to the computing unit 11.

[0027] According to the current embodiment, the circuit board is four-layered and therefore has four layers. This is in Figure 3The diagram is shown in a simplified side view. Multiple portions of the transmitter coil 8 and receiver coils 9, 9' are located in the first layer L1, and these coils also cross each other, for example, in their orientation.

[0028] In the second layer L2 below, there are additional portions of the transmitter coil 8 and the receiver coils 9 and 9'. Specifically, there is only one transmitter coil 8 and two receiver coils 9 and 9', which extend on layers L1 and L2 respectively.

[0029] In the lowest layer L4, the computing unit 11 is arranged on the back side 10 of the circuit board 6, as mentioned earlier. In the third layer L3, located between layer L4 and layer L2, and in layer L4, connection lines 12 for the transmitter coil 8 and connection lines 13 for the receiver coils 9, 9' are constructed. The transmitter coils 8, 8' and the receiver coils 9, 9' are electrically connected to the computing unit 11 through these connection lines. Of course, the connection lines 12, 13 extend through all layers required to reach the corresponding coils 8, 8', 9, 9'. However, in layers L3 and L4, the connection lines 12, 13 extend at least substantially parallel to each other, as... Figure 3 As shown in the simplified version.

[0030] Figure 4 A simplified detailed top view of circuit board 6 is shown, in which connecting lines 12 and 13 extending radially or non-axially in layers L3 and L4 are parallel to each other, such that the connecting lines directly overlap each other. Here, the connecting lines 12 and 13 between computing unit 11 and coils 8 and 9 extend as long as possible parallel to the third layer L3 and the fourth layer L4, or extend parallel to the same layer L3 and L4. This minimizes the inductive effect in the connecting areas, thereby minimizing the offset in the signal. This offset can be at least ignored if it does not lead to erroneous measurements or if the output signal is as linear as possible. Furthermore, the connecting lines 12 and 13 between computing unit 11 and coils 8 and 9 are preferably as short as possible to also minimize interference fields or signals generated by induction.

[0031] Although in modern sensor devices, computational units are typically not applied to the back of a four-layer circuit board because induction in the coil connection area causes large offsets and thus high linearity deviations, the advantageous implementation of sensor device 5 according to the current embodiment is suitable for making this possible in a four-layer circuit board without the need for additional shielding layers between the layers. Sine and cosine output signals are obtained from the demodulated signals of receiver coils 9, 9'. To obtain a linear signal that depends on the path or angle, an ATAN function is constructed. The more similar the signal is to the sine and cosine, the lower the higher harmonic signal components, and the more linear the output signal. Linearity can be quantified: if the ATAN (signal 1, signal 2) derives a perfect ATAN (a straight line) from the sine and cosine, a linearity deviation is obtained, i.e., the deviation from the ideal sine and cosine signals. Since only a limited number of pivots of the path-signal curve can typically be stored, high nonlinearity means either low accuracy or increased calibration workload. For motors with poor regulators, this can lead to vibration and noise. To reduce errors, for example, a shielding layer made of copper has traditionally been placed between layers to reduce the influence of interference fields. Due to the advantageous design of the current position sensor device 5, this layer can be omitted for the aforementioned reasons, thus reducing the overall cost of the circuit board 6 and saving more structural space.

[0032] Although the actuator element to be inspected according to this embodiment is rotor 4, according to another embodiment the actuator element is linear actuator element 15, such as... Figure 5 As shown. This differs from the previous embodiment in that the circuit board 6 is not annular but strip-shaped, wherein coils 8, 9, 8', and 9' extend longitudinally along the strip-shaped circuit board 6. Furthermore, the computing unit 11 is also arranged in layer L4, and the coils are also arranged in layers L1 and L2. Here, the connection lines from the coils to the computing unit 11 are at least substantially parallel to each other in different layers, and in particular, directly overlap each other.

[0033] As an alternative to having connecting lines 12 and 13 extend overlapping each other in different layers, it is also possible to have connecting lines 12 and 13, or at least one of connecting lines 12 and 13, extend parallel to each other in layers L1 to L4 or other layers. This parallel extension can also reduce interference signals.

Claims

1. An inductive position sensor device (5) for detecting the position of a coupling element, the coupling element being arranged on a movable actuator element of a motor (2), the inductive position sensor device having at least one transmitter coil (8, 8'), at least one receiver coil (9, 9'), and a computing unit (11) for generating electromagnetic waves, the receiver coil for detecting electromagnetic waves generated by the transmitter coil (8) and affected by the actuator element, the computing unit being designed to manipulate the transmitter coil (8) and evaluate the electromagnetic waves detected by the receiver coil (9, 9') to determine the position, wherein, The coils (8, 9) are arranged on the front side of a common circuit board (6), while the computing unit (11) is arranged on the back side of the common circuit board, wherein the coils (8, 8', 9, 9') and the computing unit (11) are electrically connected by connecting lines (12, 13) extending along and through the circuit board (6), characterized in that the connecting lines (12, 13) extend substantially parallel to each other, and the circuit board (6) has a first layer (L1), a second layer (L2), a third layer (L3), and a fourth layer (L4) that overlap each other. The circuit board (6) has four layers (L4), wherein at least one of the coils (8, 9, 8', 9') is arranged at least partially on the first layer (L1) and the second layer (L2), the computing unit (11) is arranged on the fourth layer (L4), and the parallel segments of the connecting lines (12, 13) are located at least on the third layer (L3) and / or the fourth layer (L4), and the connecting lines (12, 13) extend at least substantially parallel to each other on different layers (L3, L4) of the circuit board (6).

2. The inductive position sensor device according to claim 1, characterized in that, The connecting lines (12, 13) extend parallel to each other at least partially overlapping at different levels (L3, L4).

3. The inductive position sensor device according to claim 1 or 2, characterized in that, The connecting lines (12, 13) extend at least substantially parallel to each other on the layers (L3, L4) of the circuit board.

4. The inductive position sensor device according to claim 1 or 2, characterized in that, A transmitter coil (8) and at least two receiver coils (9, 9') are provided, wherein the receiver coils (9, 9') are arranged staggered from each other on the actuator element.

5. The inductive position sensor device according to claim 1 or 2, characterized in that, The corresponding receiver coils (9, 9') extend at least on the first and second layers.

6. The inductive position sensor device according to claim 1 or 2, characterized in that, The at least one transmitter coil (8) extends only on the first layer (L1) or at least on both the first and second layers.

7. The inductive position sensor device according to claim 1 or 2, characterized in that, The circuit board (6) has no shielding layer.

8. The inductive position sensor device according to claim 1 or 2, characterized in that, The circuit board (6) is either disc-shaped or strip-shaped.

9. The inductive position sensor device according to claim 8, characterized in that, The circuit board (6) is in the shape of a circular disc.

10. The inductive position sensor device according to claim 1 or 2, characterized in that, At least one EMV anti-interference capacitor (14) is arranged on the back side (10).

11. A drive device (1) having a motor having an inductive position sensor device (5) associated with the motor, the inductive position sensor device being used to detect the position of a movable actuator element of the motor, characterized in that, The inductive position sensor device (5) is constructed according to any one of claims 1 to 10.

12. The driving device according to claim 11, characterized in that, The drive unit is used for the parking brake of a motor vehicle.

13. The driving device according to claim 11, characterized in that, The actuator element is a rotor (4) or a linear actuator (15).

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