Inductive measurement assembly and pedal assembly for vehicle

Abstract

The embodiment of the invention relates to an inductive measurement assembly and a pedal assembly for a vehicle. The invention relates to an inductive measuring assembly comprising at least one evaluation and control unit, a circuit carrier on which at least one transmitting structure and at least one receiving structure are arranged, and at least one electrically conductive coupling element, the at least one evaluation and control unit is designed to couple a periodic alternating electrical signal into the at least one transmitting structure and to receive a measurement signal (MS) sensed by the at least one electrically conductive coupling element into the at least one receiving structure on the basis of the principle of eddy current, the invention relates to an inductive measuring assembly (10) for measuring a circuit carrier (7) and at least one electrically conductive coupling element (14), which measuring signal represents a current distance (A) or a change in the distance (A) between the circuit carrier (7) and the at least one electrically conductive coupling element (14), and for generating and outputting an output signal on the basis of the measuring signal, and to a pedal assembly (1) having at least one such inductive measuring assembly (10).

Description

Technical Field

[0001] The present invention relates to an inductive measuring assembly and also to a pedal assembly for a vehicle having such an inductive measuring assembly. Background Art

[0002] Pedal assemblies are known from the prior art, for example for implementing brake pedals or travel pedals. Such pedal assemblies for implementing brake pedals are designed, for example, as hydraulic systems with at least one hydraulic cylinder. In order to provide a sufficient fluid volume for actuating the at least one hydraulic cylinder, corresponding brake pedals have a long actuation stroke of about 70 mm. Usually, the brake pedal is actuated by a lever that is significantly longer than the height of the pedal surface. As a result, it is largely irrelevant where the foot is placed on the pedal surface for actuation.

[0003] The electrification of the brake system (brake-by-wire) makes it possible to reduce the actuation distance by using force sensors and also to achieve fine-tuned operation. The goal is to replace the classic brake pedal with a force-sensitive pedal with an actuation distance of less than 2 mm that is no longer perceived by the driver as a "pedal distance". The main challenges for force sensors are dirt resistance, a flat design, flat measurement of the load or detection of uneven pedal loading, electromagnetic compatibility (mainly relevant for electric vehicles), functional safety and competitive production costs.

[0004] Force measurement can also be achieved by combining linear spring elements with distance measurement. Inductive sensors for distance measurement with coils are widely used in industrial environments. The basic principle of such inductive sensors is to change the inductance or its quality by changing the position of the sensor relative to the conductive and / or ferromagnetic parts. As a component of an oscillating circuit, the coil usually emits a magnetic field, which induces eddy currents in the conductive material passing by, so this sensor design is also called eddy current sensor. The amplitude and frequency of the oscillating circuit change. When the change is determined, the output is switched by a Schmidt trigger or the amplitude can be converted into a distance. Usually, the coil is wound around a ferrite core. This design ensures that such sensors are large in the axial sensing direction and small in orthogonal to the sensing direction. A disadvantage for use in pedals is the installation space requirement, especially in the axial direction. Equally disadvantageous is the complex design with the wound coil. The complex design makes these sensors expensive. Most inductive distance sensors work as switches, i.e. their output can only assume two states. The resolution is too low for use in pedals.

[0005] DE 198 11 268 A1 discloses an operating device for influencing a foot-operated drive or deceleration device in a motor vehicle, the operating device having a signal generator, which generates a control signal dependent on the operating path and has a power supply line. The signal generator has a body that is elastic and electrically conductive, and is provided with a first electrical contact region that extends on a first surface of the body and is electrically conductively connected to the body on the one hand and to the first power supply line on the other hand; and a second electrical contact region that extends on a second surface of the body opposite to the first surface and is electrically conductively connected to the body on the one hand and to the second power supply line on the other hand. The resistance of the body between the two contact regions is dependent on the distance between the two contact regions, and a measuring transducer is connected downstream of the signal generator, whose input is connected to the first and second contact regions via the power supply line and at whose output a control signal can be taken, which constitutes a measure of the resistance. Summary of the invention

[0006] The inductive measuring component according to the invention has the following advantages: the eddy current principle used can provide a safe and inexpensive inductive measuring component, which can still generate a proportional signal at a "small" axial actuation stroke of less than two millimeters (2 mm), which is suitable, for example, for activating a brake pedal for a braking function or for activating an acceleration function.

[0007] Embodiments of the present invention provide an inductive measuring assembly having at least one evaluation and control unit, a circuit carrier, on which at least one transmitting structure and at least one receiving structure are arranged, and at least one electrically conductive coupling element. The at least one evaluation and control unit is designed to couple a periodic alternating electrical signal into the at least one transmitting structure, and to receive a measurement signal induced into the at least one receiving structure based on the eddy current principle via the at least one electrically conductive coupling element, the measurement signal representing the current distance or distance change between the circuit carrier and the at least one electrically conductive coupling element, and to generate and output an output signal based on the measurement signal.

[0008] In addition, a pedal assembly for a vehicle is proposed, which has at least one movably supported pedal that can be operated over a predetermined axial operating stroke against the force of at least one spring element; and has at least one inductive measuring assembly that is implemented to detect the operation of the pedal and the corresponding operating stroke.

[0009] Embodiments of the inductive measuring arrangement utilize the eddy current principle, wherein an electromagnetic field is coupled from at least one transmitting structure via at least one conductive coupling element into one or more receiving structures. The position, in particular the distance, of the at least one conductive coupling element relative to the at least one transmitting structure and the at least one receiving structure determines the strength of the inductive coupling. The coupling can be measured via an induced voltage in the at least one receiving structure and allows the distance between the at least one conductive coupling element and the circuit carrier to be determined.

[0010] Because an axial operating stroke of about one millimeter is sufficient to change the output signal or measurement signal by a factor of two using the eddy current principle, the distance to be detected or the distance change to be detected between the circuit carrier and the axial operating stroke to be detected of at least one conductive coupling element of the inductive measuring component or the pedal component is preferably predetermined in the range of 1 mm to 5 mm. This allows the inductive measuring component and the corresponding pedal component to have a flat structural form in the axial sensing direction. A linear relationship between the operating force and the output signal of the inductive measuring component can be achieved through appropriate design. In addition, the implementation of the inductive measuring component can replace the binary "switch output" to achieve a continuous output signal with high resolution and accuracy. In common force sensors with strain gauges, in addition to unfavorable point measurements, the design freedom is also very limited because the deformable body and the strain gauge must be prevented from being at the same position. The implementation of the inductive measuring component can include a possible tilted measurement of the operating force in a planar manner. The implementation of the inductive measuring component can achieve a very high degree of redundancy independent of the deformable body by separating the deformable body from the measuring part. This can achieve very high functional safety. The inductive distance measurement performed by the implementation of the inductive measuring component is inherently interference-resistant when properly designed. Furthermore, the embodiment of the inductive measuring assembly enables a simple construction with inexpensive components for a pedal assembly for a vehicle. Furthermore, no wound coil is required. The inductive measuring assembly can preferably be implemented on a standard circuit board. Furthermore, there is more installation space on existing circuit boards for different redundancies for distance measurement, for example on an optical or magnetic basis.

[0011] The analysis, evaluation and control unit can currently be understood as a circuit for processing or analyzing and evaluating the detected sensor signals. The analysis, evaluation and control unit can have at least one interface, which can be constructed in hardware and / or software. In the case of hardware construction, the interface can be, for example, a part of a so-called system ASIC module (ASIC: application-specific integrated circuit), which contains various functions of the analysis, evaluation and control unit. However, the interface can also be an independent integrated circuit or at least partially composed of discrete structural elements. For example, in the case of software construction, the interface can be a software module that exists on a microcontroller, for example, together with other software modules. It is also advantageous that a computer program product with program code can be stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory, etc. and is used to perform analysis and evaluation when the program is executed by the analysis, evaluation and control unit.

[0012] The measures and developments listed in preferred embodiments make it possible to achieve advantageous improvements to the inductive measuring arrangement provided by the invention.

[0013] Particularly advantageously, at least one conductive coupling element or circuit carrier can be coupled to a movable body, and the movable body can overcome the force movement of at least one spring element. Here, at least one analysis, evaluation and control unit can also be implemented as a predetermined characteristic based on the measurement signal and at least one spring element to generate and output another output signal, and this other output signal represents the current operating force acting on the movable body. The output signal can be generated and output by a common analysis, evaluation and control unit or two independent analysis, evaluation and control units, for example. Therefore, two independent analysis, evaluation and control units can be arranged on the circuit carrier of the inductive measurement component. Alternatively, a common analysis, evaluation and control unit or a first analysis, evaluation and control unit can be arranged on the circuit carrier of the inductive measurement component. In addition, a common analysis, evaluation and control unit or a second analysis, evaluation and control unit can be arranged in a superior controller electrically connected to the inductive measurement component. Using the eddy current principle has a plurality of technical advantages for realizing a force measurement of an inductive measurement component with a negligible small axial operating stroke. The applied operating force or pedal force can be derived by a small axial operating stroke of the movable body or a small distance change between at least one conductive coupling element and the circuit carrier in combination with the known characteristics of at least one spring element. The desired force-displacement characteristic curve for the operating force can be set by the characteristics of the at least one spring element. The spring characteristic can preferably be designed in such a way that the relationship between the force applied to the at least one spring element and the distance change between the at least one conductive coupling element and the circuit carrier is linear. Of course, nonlinear behavior can also be used in order to actively influence the feeling when operating the movable body or the pedal. In the case of a known force-displacement characteristic curve, the distance change can still be converted into an operating force.

[0014] In an advantageous configuration of the inductive measuring assembly, the movable body can be, for example, a pedal of a pedal assembly for a vehicle. In the embodiment of the pedal assembly, since at least one spring element is separated from at least one transmitting structure and at least one receiving structure on a common circuit carrier, the separation of the deformation element and the sensor surface can be simply achieved. Therefore, it is possible to simply adjust the force measurement area without changing at least one transmitting structure and at least one receiving structure on a common circuit carrier. In addition, good electromagnetic compatibility can be achieved by a fixed operating frequency and / or a differential measurement principle. At least one spring element can be implemented as a disc spring, a short helical spring or an elastomer element, etc. At least one spring element can also be assembled from a plurality of distributed springs. In addition, at least one spring element can also be implemented as a tensilely loaded crimp that connects the pedal to the frame. Here, at least one conductive coupling element or the circuit carrier can be coupled to the pedal and move with the pedal when the pedal is operated. This means that at least one conductive coupling element can be coupled to the pedal, while the circuit carrier can be fixed. Thus, when the pedal is operated, at least one conductive coupling element can move with the pedal, while the circuit carrier does not move together. Alternatively, the circuit carrier can be coupled to the pedal, while at least one conductive coupling element can be fixed. When the pedal is actuated, the circuit carrier can move with the pedal without the at least one conductive coupling element moving with it. In this case, the coupling or connection between the pedal and the at least one conductive coupling element or the circuit carrier can be implemented in such a way that the current distance between the circuit carrier and the at least one conductive coupling element decreases when the pedal is actuated. Alternatively, the coupling or connection between the pedal and the at least one conductive coupling element or the circuit carrier can be implemented in such a way that the current distance between the circuit carrier and the at least one conductive coupling element increases when the pedal is actuated. This alternative configuration can be used in particular for applications that require particularly high precision in the low force range.

[0015] In another advantageous embodiment of the inductive measuring assembly, the at least one transmitting structure can include at least one planar transmitting coil and the at least one receiving structure can include at least one planar receiving coil. In the case of planar coils, the windings are not made of wires, such as copper wires or the like, but rather of etched conductor tracks of the circuit carrier. This enables a simple and cost-effective implementation of the at least one transmitting structure and the at least one receiving structure in the circuit carrier.

[0016] In another advantageous embodiment of the inductive measuring assembly, the circuit carrier can be embodied as a multilayer printed circuit board. This enables simple and cost-effective production of the circuit carrier. Alternatively, the circuit carrier can be embodied as an injection-molded busbar or an injection-molded circuit carrier (MID: molded interconnect device).

[0017] In another advantageous embodiment of the inductive measuring assembly, at least one planar transmitting coil and / or at least one planar receiving coil can be arranged in a plurality of layers of the printed circuit board. In this case, sections of the at least one planar transmitting coil and / or at least one planar receiving coil arranged in different layers can be electrically contacted with one another via through-holes and connected in series. In this case, planar can be understood to mean that the spatial extent in the “plane” is significantly greater than the spatial extent on the layers of the printed circuit board.

[0018] In another advantageous embodiment of the inductive measuring assembly, the circuit carrier can be arranged between two conductive coupling elements. In this case, a current first distance between the first conductive coupling element and the circuit carrier can be reduced when the movable body moves due to an operating force, while a current second distance between the second conductive coupling element and the circuit carrier can be increased when the movable body moves due to an operating force. By a suitable arrangement of the two conductive coupling elements relative to the circuit carrier, the relationship between the voltage induced in the at least one receiving structure and the distance between the at least one conductive coupling element and the circuit carrier can be largely linearized. In this case, the use of two conductive coupling elements can provide an improved linearization than the use of only one conductive coupling element.

[0019] In another advantageous embodiment of the inductive measuring assembly, at least one receiving structure can include at least one coil pair, which includes two adjacently arranged planar receiving coils with opposite windings. External interfering magnetic fields can be effectively suppressed by the opposite windings of the two receiving coils.

[0020] In another advantageous embodiment of the inductive measuring arrangement, the planar receiving coils of a coil pair can be, for example, geometric polygons, preferably geometric rectangles or triangles, or geometric circles or geometric semicircles or geometric ellipses or other suitable geometric shapes.

[0021] In another advantageous embodiment of the inductive measuring assembly, the transmitting coils of at least one plane of the corresponding transmitting structure can geometrically surround the coil pair of at least one receiving structure, so that at least one coil pair is completely arranged in the plane spanned by the transmitting coils of the at least one plane.

[0022] In another advantageous embodiment of the inductive measuring assembly, at least one conductive coupling element can at least partially cover the surface expanded by at least one coil pair and the surface expanded by at least one planar transmitting coil. Preferably, at least one conductive coupling element is based on the same geometry as at least one receiving coil. In addition, at least one conductive coupling element can, for example, cover half of the surface expanded by the two receiving coils of at least one coil pair. By covering half of the surface expanded by the receiving coils of at least one coil pair, it can be achieved that a signal is generated in the two receiving coils by forming a difference, while suppressing external interference effects that also act on the two receiving coils. Of course, different coverage levels can also be implemented, such as covering a quarter or a third of the receiving coils of at least one coil pair. Energy can be transferred from at least one transmitting coil to at least one receiving coil by at least one conductive coupling element depending on the distance from the circuit carrier, and the energy can be measured as a voltage or current on at least one receiving coil. Half coverage can also be established in the following way, that is, at least one conductive coupling element has a contour structure with different heights on the two receiving coils. At least one conductive coupling element can also be manufactured in circuit board technology similar to the circuit carrier in order to achieve the necessary partial overlap of the receiving coils. In this case, the at least one electrically conductive coupling element can be manufactured in such a way that an electrically conductive surface is arranged on the first receiving coil of the at least one coil pair, while only a non-conductive carrier material is arranged on the second receiving coil of the at least one coil pair. Alternatively, the at least one electrically conductive coupling element can be designed as a busbar overmolded with plastic or as an injection-molded circuit carrier (MID: molded interconnect device).

[0023] In another advantageous configuration of the inductive measuring assembly, at least three coil pairs respectively surrounded by a planar transmitting coil can form a sensor array, which can be at least partially covered by a common conductive coupling element or two different conductive coupling elements. Here, at least one analysis and evaluation and control unit can also be implemented to receive and analyze the measurement signals induced in the multiple coil pairs of at least one receiving structure and determine the spatial position of the movable body based on the analysis and evaluation. A multi-channel structure can thus be realized, which can realize an improved relationship between the operating force applied to the movable body and the movement detected by the inductive measuring assembly in an advantageous manner. Different forces acting on the movable body or the pedal due to the centering of the operating force and the current distance or distance change between the circuit carrier and the at least one conductive coupling element can thus be detected by the sensor array. By determining the spatial position of the movable body (which can usually be different when operated by the user), it is possible to reliably detect whether the pedal is operated at all. It is possible to compensate for the offset that may be caused by aging during operation. In addition, it is possible to identify faults, such as when the temperature characteristics of each channel change, and to identify contamination in the air chamber between the at least one conductive coupling element and the circuit carrier. Furthermore, due to the redundancy in the embodiment as a sensor array, the measurement signals can be verified, whereby high requirements for functional safety can be met. Thus, for example, degradation or failure of a single receiving coil can be reliably detected by comparison with other receiving coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments of the invention are shown in the drawings and explained in more detail in the following description. In the drawings, the same reference numerals designate components or elements that perform the same or similar functions.

[0025] Figure 1 A sectional view of a first exemplary embodiment of a pedal assembly according to the invention for a vehicle is shown, which has a first exemplary embodiment of an inductive measuring assembly according to the invention.

[0026] Figure 2 Show Figure 1 Schematic top view of an inductive measuring assembly according to the invention.

[0027] Figure 3 Show Figure 1 and Figure 2 A schematic plan view of a first exemplary embodiment of a circuit carrier for an inductive measuring arrangement according to the invention, which is embodied as a printed circuit board.

[0028] Figure 4 A schematic top view of a second exemplary embodiment of an inductive measuring arrangement according to the invention is shown.

[0029] Figure 5 Show Figure 4 A schematic plan view of a second exemplary embodiment of a circuit carrier for an inductive measuring arrangement according to the invention, which is embodied as a printed circuit board.

[0030] Figure 6 A schematic top view of a third exemplary embodiment of an inductive measuring arrangement according to the invention is shown.

[0031] Figure 7 A sectional view of a second exemplary embodiment of a pedal assembly according to the invention for a vehicle is shown, which has a fourth exemplary embodiment of an inductive measuring assembly according to the invention.

[0032] Figure 8 Show Figure 7 Schematic top view of an inductive measuring assembly according to the invention.

[0033] Fig. 9 A schematic top view of a fifth embodiment of the inductive measuring assembly according to the present invention is shown.

[0034] Fig.10 Show Fig. 9 Schematic diagram of an electrically conductive coupling element for an inductive measuring assembly according to the invention.

[0035] Fig.11 A schematic electrical block diagram of an inductive measuring assembly according to the present invention is shown.

[0036] Fig.12 A schematic diagram of a measurement signal-distance characteristic diagram shows the characteristic curves of two coil pairs of an inductive measuring arrangement according to the invention. DETAILED DESCRIPTION

[0037] As from Figures 1 to 9 As can be seen, the illustrated embodiments of the inductive measuring assembly 10, 10A, 10B, 10C, 10D, 10E according to the invention each comprise at least one evaluation and control unit 11, a circuit carrier 7, on which at least one transmitting structure 12 and at least one receiving structure 16 are arranged, and at least one electrically conductive coupling element 14. In this case, the at least one evaluation and control unit 11 is designed to couple a periodic alternating electrical signal into the at least one transmitting structure 12 and to receive a measurement signal MS induced into the at least one receiving structure 16 by the at least one electrically conductive coupling element 14 based on the eddy current principle, which measurement signal represents the current distance A or a change in the distance A between the circuit carrier 7 and the at least one electrically conductive coupling element 14, and to generate and output an output signal AS based on the measurement signal MS.

[0038] The current distance A between the circuit carrier 7 and the at least one conductive coupling element 14 determines the degree of coupling between the at least one transmitting structure 12 and the at least one receiving structure 16. The relative movement between the circuit carrier 7 and the at least one conductive coupling element 14 changes the current distance between the circuit carrier 7 and the at least one conductive coupling element 14 and thereby changes the measurement signal MS induced into the at least one receiving structure 16. Here, at least one conductive coupling element 14 or the circuit carrier 7 is coupled to a movable body 3, which can move against the force of at least one spring element 15. The at least one evaluation and control unit 11 is further embodied to generate and output a further output signal based on the predetermined characteristics of the measurement signal MS and the at least one spring element 15, which further output signal represents the actuating force F currently acting on the movable body 3. In the illustrated embodiment, a common evaluation and control unit 11 is embodied to generate the output signal AS of each inductive measuring component 10, 10A, 10B, 10C, 10D, 10E. Figure 1 and Figure 7 In the illustrated embodiment of the pedal assembly 1 for a vehicle, the movable bodies 3 are respectively pedals 3A.

[0039] As from Figure 1 and Figure 7 It can also be seen that the illustrated embodiments of the pedal assembly 1, 1A, 1B according to the invention for a vehicle each include a movably supported pedal 3A, which can be actuated over a predetermined small axial actuation travel against the force of at least one spring element 15; a circuit carrier 7 and at least one inductive measuring component 10, 10A, 10B, 10C, 10D, 10E, which is implemented to detect the actuation of the pedal 3A and the corresponding axial actuation travel. Figure 1 and Figure 7 It can also be seen that in the illustrated embodiment of the pedal assembly 1, 1A, 1B, the evaluation and control unit 11 is respectively arranged on the underside of the circuit carrier 7. Figure 1 and Figure 7 It can also be seen that in the illustrated embodiment of the pedal assembly 1 , 1A, 1B, at least one electrically conductive coupling element 14 is coupled to the pedal 3A and moves together with the pedal when the pedal 3A is actuated.

[0040] In an alternative exemplary embodiment (not shown) of the pedal assembly 1 , the circuit carrier 7 is coupled to the movable body 3 or the pedal 3A and moves together with it when the movable body 3 or the pedal 3A is actuated.

[0041] As from Figure 1 and Figure 7It can also be seen that in the illustrated embodiment of the pedal assembly 1A, 1B, the circuit carrier 7 having at least one transmitting structure 12 and at least one receiving structure 16 is arranged in the housing 9. In addition, the plurality of spring elements 15 of the illustrated embodiment of the pedal assembly 1A, 1B are each designed as a helical spring 15A, which is supported on the carrier 5 designed as a base plate 5A. In this case, the base plate 5A forms the bottom of the housing 9.

[0042] As from Figure 1 It can also be seen that in the first illustrated embodiment of the pedal assembly 1A, the conductive coupling element 14 is arranged on a retaining structure 4 implemented as a retaining plate 4A, which is coupled or connected to the housing 9 via a connecting tab 3.1. Here, the connecting tab 3.1 is guided through a cover of the housing 9, which is not indicated in detail. As a result, the coupling element 14 is arranged between the circuit carrier 7 and the pedal 3A and the distance A between the coupling element 14 and the circuit carrier 7 is reduced when an operating force F is applied to the pedal 3A. The end region of the retaining plate 4 forms a stop 4.1, which, in combination with the cover of the housing 9, defines the illustrated starting position of the retaining plate 4 and thus of the pedal 3A. The spring element 15 implemented as a coil spring 15A acts as a compression spring and presses the retaining plate 4 against the cover of the housing 9 into the illustrated starting position. As can be seen from Figure 1 It can also be seen that the circuit carrier 7 is firmly connected to the substrate 5A via spacer elements (not shown in detail).

[0043] As from Figures 1 to 9 It can also be seen that in the exemplary embodiment shown, at least one transmitting structure 12 comprises at least one planar transmitting coil 13, 13A, 13B, 13C, 13D. At least one receiving structure 16 comprises at least one planar receiving coil 17, 17A, 17B. Furthermore, the circuit carrier 7 is designed as a multilayer printed circuit board 7A, 7B, 7C. Here, at least one planar transmitting coil 13, 13A, 13B, 13C, 13D and at least one planar receiving coil 17, 17A, 17B are arranged in a plurality of layers of the printed circuit board 7A. Sections of at least one planar transmitting coil 13, 13A, 13B, 13C, 13D and at least one planar receiving coil 17, 17A, 17B arranged in different layers are electrically contacted with each other and connected in series via plated contacts 13, 1, 17.1.

[0044] In the illustrated embodiment of the inductive measuring assembly 10, 10A, 10B, 10C, 10D, 10E, at least one receiving structure 16 comprises at least one coil pair 18, 18A, 18B, 18C, 18D, which comprises two adjacently arranged planar receiving coils 17, 17A, 17B with opposite windings, which are electrically connected in series. This means that the winding of one of the two planar receiving coils 17, 17A, 17B extends clockwise, while the winding of the other of the two planar receiving coils 17, 17A, 17B extends counterclockwise. In an ideal case, the surface spanned by the receiving coils 17, 17A, 17B with the windings extending clockwise is exactly as large as the surface spanned by the receiving coils 17, 17A, 17B with the windings extending counterclockwise. In this way, external interfering magnetic fields are suppressed, since in total no voltage is induced in reception coils 17 , 17A, 17B by the interfering magnetic fields, or the voltages induced in the subwindings add up to zero.

[0045] The at least one planar transmitting coil 13, 13A, 13B, 13C, 13D of the corresponding transmitting structure 12 geometrically surrounds at least one coil pair 18, 18A, 18B, 18C, 18D of at least one receiving structure 16. The most important property of the at least one planar transmitting coil 13, 13A, 13B, 13C, 13D is to provide inductance. This inductance is mainly related to the outer dimensions (height and width) of the at least one planar transmitting coil 13, 13A, 13B, 13C, 13D and the number of windings. Typical outer dimensions are in the region of 10 mm x 10 mm. The surface spanned by the at least one transmitting coil 13, 13A, 13B, 13C, 13D can have a rectangular, circular, elliptical or other suitable shape. The planar receiving coils 17, 17A, 17B of each coil pair 18, 18A, 18B, 18C, 18D are geometrically located within the corresponding planar transmitting coils 13, 13A, 13B, 13C, 13D. The terminals of the receiving coils 17, 17A, 17B are led out from the corresponding planar transmitting coils 13, 13A, 13B, 13C, 13D and connected to at least one evaluation and control unit 11. The planar receiving coils 17, 17A, 17B of the coil pairs 18, 18A, 18B, 18C, 18D can have a geometric polygon, preferably a geometric rectangle or a geometric triangle, or a geometric circle or a geometric semicircle or a geometric ellipse. Of course, the planar receiving coils 17, 17A, 17B can also have other suitable geometric shapes.

[0046] As from Figures 1 to 9It can also be seen that at least one electrically conductive coupling element 14, 14A, 14B at least partially covers the area spanned by at least one coil pair 18, 18A, 18B, 18C, 18D and the area spanned by at least one planar transmitting coil 13, 13A, 13B, 13C, 13D. The geometry of at least one electrically conductive coupling element 14, 14A, 14B is preferably based on the same geometry as the receiving coil 17, 17A, 17B.

[0047] As from Figure 2 and Figure 3 It can further be seen that the first embodiment of the inductive measuring component 10A shown includes a transparently shown circuit carrier 7 implemented as a multi-layer circuit board 7A and a rectangular conductive coupling element 14, wherein the circuit carrier has a receiving structure 16 and a transmitting structure 12, wherein the receiving structure has two coil pairs 18A, 18B, wherein the coil pairs each have two rectangular planar receiving coils 17A, 17B, wherein the rectangular planar receiving coils each have eight windings; and the transmitting structure has a rectangular planar transmitting coil 13, wherein the rectangular planar transmitting coil has ten windings. Here, the planar receiving coils 17A, 17B of the two coil pairs 18A, 18B and the planar transmitting coil 13 of the transmitting structure are respectively arranged in two layers of the circuit board 7A. As can be seen in particular from Figure 3 It can be seen that the first planar receiving coil 17A of the first coil pair 18A on the left side of the diagram is arranged above the second planar receiving coil 17B of the first coil pair 18A. The winding of the first planar receiving coil 17A of the first coil pair 18A extends clockwise, while the winding of the second planar receiving coil 17B of the first coil pair 18A extends counterclockwise. The first planar receiving coil 17A of the second coil pair 18B on the right side of the diagram is arranged above the second planar receiving coil 17B of the second coil pair 18B. The winding of the first planar receiving coil 17A of the second coil pair 18B extends counterclockwise, while the winding of the second planar receiving coil 17B of the second coil pair 18B extends clockwise. As can be seen from Figure 2 and Figure 3 It can also be seen that the planar transmitting coil 13 geometrically surrounds the planar receiving coils 17A, 17B of the two coil pairs 18A and 18B. The planar receiving coils 17A, 17B of the two coil pairs 18A, 18B each have eight windings. Figure 2 It can further be seen that the rectangular electrically conductive coupling element 14 covers the upper half of the planar transmitting coil 13 in the illustration and the two first planar receiving coils 17A of the two coil pairs 18A, 18B.

[0048] As from Figure 4 and Figure 5It can further be seen that the second embodiment of the inductive measuring component 10B shown comprises, similarly to the first embodiment, a transparently shown circuit carrier 7 embodied as a multilayer circuit board 7B and a triangular conductive coupling element 14, the circuit carrier having a receiving structure 16 and a transmitting structure 12, the receiving structure having two coil pairs 18A, 18B, the two coil pairs each having two triangular planar receiving coils 17A, 17B, the triangular planar receiving coils each having eight windings; the transmitting structure having a rectangular planar transmitting coil 13, the rectangular planar transmitting coil having ten windings. Here, the planar receiving coils 17A, 17B of the two coil pairs 18A, 18B and the planar transmitting coil 13 of the transmitting structure are respectively arranged in two layers of the circuit board 7A. As can be seen in particular from Figure 5 It can be seen that the first planar receiving coil 17A of the first coil pair 18A shown at the top in the diagram is arranged on the left side next to the second planar receiving coil 17B of the first coil pair 18A. The winding of the first planar receiving coil 17A of the first coil pair 18A extends clockwise, while the winding of the second planar receiving coil 17B of the first coil pair 18A extends counterclockwise. The first planar receiving coil 17A of the second coil pair 18B shown at the bottom in the diagram is arranged on the left side next to the second planar receiving coil 17B of the second coil pair 18B. The winding of the first planar receiving coil 17A of the second coil pair 18B extends counterclockwise, while the winding of the second planar receiving coil 17B of the second coil pair 18B extends clockwise. As can be seen from Figure 4 and Figure 5 It can be further seen that the planar transmitting coil 13 geometrically surrounds the receiving coils 17A, 17B of the two coil pairs 18A, 18B. The planar receiving coils 17A, 17B of the two coil pairs 18A, 18B each have eight windings. Figure 4 It can further be seen that the triangular conductive coupling element 14 covers the right quarter of the planar transmitting coil 13 in the illustration and the two second planar receiving coils 17B of the two coil pairs 18A, 18B.

[0049] As from Figure 6It can be seen that the third exemplary embodiment of the inductive measuring assembly 10C shown comprises a circuit carrier 7 designed as a multilayer circuit board 7C, which has a receiving structure 16 and a transmitting structure 12, which has four coil pairs 18A, 18B, 18C, 18D, each of which has two triangular planar receiving coils 17A, 17B; and a rectangular (here square) conductive coupling element 14, which is shown transparently. The four planar transmitting coils 13A, 13B, 13C, 13D each surround one of the coil pairs 18A, 18B, 18C, 18D, so that a sensor array 19 with four basic units is formed, each of which consists of a planar transmitting coil 13A, 13B, 13C, 13D and a coil pair 18A, 18B, 18C, 18D.

[0050] As from Figure 6 It can also be seen that the two triangular planar receiving coils 17A and 17B of the first coil pair 18A arranged at the upper left in the diagram are geometrically surrounded by the first planar transmitting coil 13A. Here, the first triangular planar receiving coil 17A is arranged to the left of the second triangular planar receiving coil 17B. The two triangular planar receiving coils 17A and 17B of the second coil pair 18B arranged at the lower left in the diagram are geometrically surrounded by the second planar transmitting coil 13B. Here, the first triangular planar receiving coil 17A is arranged to the left of the second triangular planar receiving coil 17B. The two triangular planar receiving coils 17A and 17B of the third coil pair 18C arranged at the upper right in the diagram are geometrically surrounded by the third planar transmitting coil 13C. Here, the first triangular planar receiving coil 17A is arranged to the right of the second triangular planar receiving coil 17B. The two triangular planar receiving coils 17A and 17B of the fourth coil pair 18D arranged at the lower right in the diagram are geometrically surrounded by the fourth planar transmitting coil 13D. Here, the first triangular planar receiving coil 17A is arranged to the right of the second triangular planar receiving coil 17B. As from Figure 6 It can be further seen that in the illustrated embodiment, the square conductive coupling element 14 is arranged tilted 90° so that it covers half of the four planar transmitting coils 13A, 13B, 13C, 13D and the second planar receiving coil 17B of the four coil pairs 18A, 18B, 18C, 18D.

[0051] Here, the evaluation and control unit 11 is further implemented to receive and evaluate the measurement signals MS induced in the plurality of coil pairs 18A, 18B, 18C, 18D of the receiving structure 16 and determine the spatial position of the movable body 3 or the conductive coupling element 14 coupled to the movable body 3 based on the evaluation. In this way, a multi-channel structure can be realized and different force effects on the movable body 3 or on the pedal 3A or on the conductive coupling element 14 can be detected by the sensor array 19. The tilt caused on the two axes of the movable body 3 or the pedal 3A or the conductive coupling element 14 as well as the centering of the actuating force and the current distance A between the circuit carrier 7 and the conductive coupling element 14 or the change in the distance A can be calculated with the help of trigonometric functions.

[0052] As from Figure 7 It can further be seen that in the second embodiment of the pedal assembly 1B shown, the circuit carrier 7 is arranged between two conductive coupling elements 14, 14A, 14B. Here, the current first distance A1 between the first conductive coupling element 14A and the circuit carrier 7 decreases when the pedal 3A is actuated, while the current second distance A2 between the second conductive coupling element 14B and the circuit carrier 7 increases when the pedal 3A is actuated. Figure 7 It can further be seen that in the second embodiment of the pedal assembly 1B shown, similarly to the first embodiment of the pedal assembly 1A, the first electrically conductive coupling element 14A is arranged on a holding structure 4 designed as a holding plate 4A, which is coupled or connected to the pedal 3A via a connecting tab 3.1. As a result, the first coupling element 14A is arranged between the circuit carrier 7 and the pedal 3A, and a first distance A1 between the first coupling element 14A and the circuit carrier 7 is reduced when an actuating force F is applied to the pedal. The second electrically conductive coupling element 14B is arranged between the circuit carrier 7 and the base plate 5A and is coupled or connected to the first electrically conductive coupling element 14A via a connecting tab, not specifically indicated, which is guided through the circuit carrier 7. When an actuating force F is applied to the pedal 3A, a second distance A2 between the second coupling element 14B and the circuit carrier 7 increases. Analogously to the first embodiment of the pedal assembly 1A, in the second embodiment of the pedal assembly 1B shown, the end region of the holding plate 4 forms a stop 4.1, which, in conjunction with the cover of the housing 9, defines the shown initial position of the holding plate 4 and thus of the pedal 3A. The spring element 15 designed as a helical spring 15A acts as a compression spring and presses the retaining plate 4 into the illustrated initial position against the cover of the housing 9. In addition, the circuit carrier 7 is firmly connected to the base plate 5A via spacer elements (not shown in detail) which are designed higher than in the first exemplary embodiment.

[0053] exist Figure 7 and Figure 8In the fourth external embodiment of the inductive measuring component 10D shown, the transparently shown circuit carrier 7, which is designed as a multilayer circuit board 7A, corresponds to the multilayer circuit board 7A of the first embodiment of the inductive measuring component 10A. This means that the receiving structure 16 has two coil pairs 18A, 18B, each of which has two rectangular planar receiving coils 17A, 17B, each of which has eight windings, and the transmitting structure 12 has a rectangular planar transmitting coil 13 with ten windings, which geometrically surrounds the planar receiving coils 17A, 17B of the two coil pairs 18A, 18B. In contrast to the first embodiment, the inductive measuring component 10D in the fourth embodiment includes two rectangular conductive coupling elements 14A, 14B, between which the circuit carrier 7 is arranged.

[0054] As from Figure 8 It can further be seen that the first rectangular conductive coupling element 14A partially covers the upper side of the circuit carrier 7. Here, the first rectangular conductive coupling element 14 covers the upper half of the planar transmitting coil 13 in the illustration and covers the two first planar receiving coils 17A of the two coil pairs 18A, 18B from above. The second rectangular conductive coupling element 14B partially covers the lower side of the circuit carrier 7. Here, the second rectangular conductive coupling element 14B covers the lower half of the planar transmitting coil 13 in the illustration and covers the two second planar receiving coils 17B of the two coil pairs 18A, 18B from below. This means that the second rectangular conductive coupling element 14B covers the areas of the transmitting coil 13 and receiving coils 17A, 17B of the two coil pairs 18A, 18B that are not covered by the first rectangular conductive coupling element 14B. Thus, a current first distance A1 between the first conductive coupling element 14A and the upper side of the circuit carrier 7 decreases when the movable body 3 or the pedal 3A moves due to the applied actuating force F, while a current second distance A2 between the second conductive coupling element 14B and the lower side of the circuit carrier 7 increases when the movable body 3 or the pedal 3A moves due to the applied actuating force F. The second target covers the area of ​​the coil system that is not covered by the first target.

[0055] exist Fig. 9 and Fig.10In the fifth external embodiment of the inductive measuring assembly 10E shown, the transparently shown circuit carrier 7, which is designed as a multilayer circuit board 7A, corresponds to the multilayer circuit board 7B of the second embodiment of the inductive measuring assembly 10B. This means that the receiving structure 16 has two coil pairs 18A, 18B, each of which has two triangular planar receiving coils 17A, 17B, each of which has eight windings, and the transmitting structure 12 has a rectangular planar transmitting coil 13 with ten windings, which geometrically surrounds the planar receiving coils 17A, 17B of the two coil pairs 18A, 18B. In contrast to the second embodiment, the inductive measuring assembly 10E in the fifth embodiment comprises two electrically conductive coupling elements 14A, 14B, between which the circuit carrier 7 is arranged.

[0056] As from Fig. 9 It can further be seen that the first triangular conductive coupling element 14A partially covers the upper side of the circuit carrier 7. Here, the first triangular conductive coupling element 14A covers the right quarter of the planar transmitting coil 13 in the illustration and covers the two second planar receiving coils 17B of the two coil pairs 18A, 18B from above. Fig.10 It can be seen that the second rectangular conductive coupling element 14B partially covers the bottom side of the circuit carrier 7 with a triangular part (which corresponds to the triangular shape of the first conductive coupling element 14A). In this case, the second conductive coupling element 14B covers the remaining three quarters of the planar transmitting coil 13 and covers the two first planar receiving coils 17A of the two coil pairs 18A, 18B from below. This means that the second conductive coupling element 14B covers the areas of the transmitting coil 13 and the receiving coils 17A, 17B of the two coil pairs 18A, 18B that are not covered by the first conductive coupling element 14B. The current first distance A1 between the first conductive coupling element 14A and the top side of the circuit carrier 7 decreases when the movable body 3 or the pedal 3A moves due to the applied operating force F, while the current second distance A2 between the second conductive coupling element 14B and the bottom side of the circuit carrier 7 increases when the movable body 3 or the pedal 3A moves due to the applied operating force F.

[0057] In the first, second, fourth and fifth embodiments of the inductive measuring assembly 10A, 10B, 10D, 10E, the receiving structure 16 comprises two coil pairs 18A, 18B respectively, so that the evaluation and control unit 11 receives and evaluates the first measurement signal MS output by the first coil pair 18A. Fig.12 K1 is used to indicate the trend of the first measurement signal and the second measurement signal MS output by the second coil pair 18B. Fig.12The trend of the second measurement signal is indicated by K2 in FIG. Here, the two measurement signals MS have different polarities. The two measurement signals MS can be evaluated to verify or achieve similar redundancy. Preferably, the sum signal that should have a "zero" value within a predetermined tolerance range is evaluated to monitor the evaluation at different polarities. In order to achieve similar redundancy, two separate evaluation and control units 11 can be used, which respectively receive and evaluate one of the measurement signals MS. Here, a common conductive coupling element 14 can be used to generate the two measurement signals MS.

[0058] As from Fig.11 It can be seen that in the exemplary embodiment shown, the evaluation and control unit 11 is designed as an ASIC module 11A (ASIC: Application Specific Integrated Circuit) and comprises an oscillator circuit 11.1, a demodulator circuit 11.2, a computing unit 11.3, an output driver 11.4 and a supply circuit for supplying and generating and providing the internal voltage required for the operation of the evaluation and control unit 11. The transmitting coil 13 is interconnected with separate capacitors C1, C2 to form an electrically excited resonant circuit. The evaluation and control unit 11 designed as an ASIC module 11A is used to maintain the resonant oscillation in the exciting resonant circuit and to evaluate the receiving coil signal. The ASIC module 11A has at least one or more drivers and one or more connections for at least one transmitting coil 13 and at least one connection for at least one receiving coil 17, 17A, 17B. In the exemplary embodiment shown, the ASIC module 11A comprises connections for a plurality of receiving coils 17A, 17B and for a plurality of coil pairs 18, 18A, 18B, 18C, 18D. The demodulator circuit 11.2 of the ASIC module 11A performs demodulation of the amplitude modulated receiving coil signal, and the calculation unit 11.3 calculates the distance A between the at least one conductive coupling element 14 and the circuit carrier 7 from the potential of the induced voltage. If necessary, the calculation unit 11.3 also performs a linearization of the characteristic curves K1, K2. The output signal AS can be transmitted to a higher-level controller in an analog or digital manner via an output driver 11.4. In addition, the temperature sensor in the ASIC module 11A can be used to compensate for thermal drifts, for example, to compensate for impedance changes of the at least one conductive coupling element 14 or the planar receiving coils 17A, 17B or the transmitting coil 13.

[0059] A magnetic field with the same frequency is generated by a high-frequency current in at least one transmitting coil 13. This magnetic field is penetrated by at least one electrically conductive coupling element 14. As a result, shielding eddy currents are induced in the thin edge layer of the coupling element 14. According to Lenz's law, these shielding currents are directed in the opposite direction to their cause (excitation field) and thus weaken the excitation field. The coupling element 14 is not located on the entire coil surface of the coil pair 18, 18A, 18B, 18C, 18D, but only on a certain part. In this way, the partial voltages induced in the coil pair 18, 18A, 18B, 18C, 18D are unbalanced. Therefore, the induced voltage is not equal to zero and is dependent on the air gap or distance between the electrically conductive coupling element 14 and the circuit carrier 7. The geometry of the at least one electrically conductive coupling element 14 is largely dependent on the shape of the receiving coil 17, 17A, 17B and covers exactly the receiving coil 17, 17A, 17B of the corresponding coil pair 18, 18A, 18B, 18C, 18D and a part of the transmitting coil 13. In principle, all materials with a conductivity of more than 1 MS / m are suitable as materials for the at least one conductive coupling element 14, in particular copper, aluminum and steel. The thickness of the conductive coupling element 14 depends on the resonant frequency of the oscillating circuit and the conductivity of the material used and should be at least in the range of the epidermal depth. Implementation with the aid of standard circuit boards is feasible and very cost-effective. The relationship between the induced receiving coil voltage and the air gap or distance A between the at least one conductive coupling element 14 and the circuit carrier is nonlinear. The relationship can be largely linearized by using two conductive coupling elements 14, 14A, 14B, between which the circuit carrier 7 is arranged. Further linearization can be achieved by an embodiment with a non-planar conductive coupling element 14, for example a hemispherical or parabolic conductive coupling element 14.

Claims

1. An inductive measuring assembly (10) comprising at least one evaluation and control unit (11), a circuit carrier (7) and at least one electrically conductive coupling element (14), on which at least one transmitting structure (12) and at least one receiving structure (16) are arranged, wherein the at least one evaluation and control unit (11) is designed to couple a periodic alternating electrical signal into the at least one transmitting structure (12) and to receive a measurement signal (MS) induced into the at least one receiving structure (16) by the at least one electrically conductive coupling element (14) based on the eddy current principle, the measurement signal representing a current distance (A) or a change in the distance (A) between the circuit carrier (7) and the at least one electrically conductive coupling element (14), and to generate and output an output signal (AS) based on the measurement signal (MS).

2. The inductive measuring assembly (10) according to claim 1, characterized in that The at least one electrically conductive coupling element (14) or the circuit carrier (7) is coupled to a movable body (3) which is movable against the force of at least one spring element (15), wherein the at least one evaluation and control unit (11) is further implemented to generate and output a further output signal based on the measurement signal (MS) and a predetermined characteristic of the at least one spring element (15), the further output signal representing the actuating force (F) currently acting on the movable body (3).

3. The inductive measuring assembly (10) according to claim 2, characterized in that The movable body (3) is a pedal (3A).

4. The inductive measuring assembly (10) according to any one of claims 1 to 3, characterized in that: The at least one transmitting structure (12) includes at least one planar transmitting coil (13), and the at least one receiving structure (16) includes at least one planar receiving coil (17).

5. The inductive measuring assembly (10) according to any one of claims 1 to 4, characterized in that: The circuit carrier (7) is embodied as a multilayer printed circuit board (7A).

6. The inductive measuring assembly (10) according to claims 4 and 5, characterized in that The at least one planar transmitting coil (13) and / or the at least one planar receiving coil (17) are arranged in a plurality of layers of the circuit board (7A), wherein sections of the at least one planar transmitting coil (13) and / or the at least one planar receiving coil (17) arranged in different layers are electrically contacted with each other via through-holes (13.1, 17.1) and connected in series.

7. The inductive measuring assembly (10) according to any one of claims 2 to 6, characterized in that The circuit carrier (7) is arranged between two conductive coupling elements (14), wherein a current first distance (A1) between a first conductive coupling element (14A) and the circuit carrier (7) decreases when the movable body (3) moves based on an applied operating force (F), and a current second distance (A2) between a second conductive coupling element (14B) and the circuit carrier (7) increases when the movable body (3) moves based on the applied operating force (F).

8. The inductive measuring assembly (10) according to any one of claims 1 to 7, characterized in that The at least one receiving structure (16) comprises at least one coil pair (18), which comprises two adjacently arranged planar receiving coils (17) with opposite windings, which are electrically connected in series.

9. The inductive measuring assembly (10) according to claim 8, characterized in that The planar receiving coil (17) of the coil pair (18) has a geometric polygonal shape, a geometric circular shape, a geometric semicircular shape, or a geometric elliptical shape.

10. The inductive measuring assembly (10) according to claim 8 or 9, characterized in that: The at least one planar transmitting coil (13) of the corresponding transmitting structure (12) geometrically surrounds the coil pair (18) of the at least one receiving structure (16).

11. The inductive measuring assembly (10) according to any one of claims 8 to 10, characterized in that The at least one conductive coupling element (14) at least partially covers a surface spanned by the at least one coil pair (18) and a surface spanned by the at least one planar transmitting coil (13).

12. The inductive measuring assembly (10) according to any one of claims 8 to 11, characterized in that The at least one conductive coupling element (14) is based on the same geometry as the at least one receiving coil (17).

13. The inductive measuring assembly (10) according to any one of claims 8 to 12, characterized in that At least three coil pairs (18) each surrounded by a planar transmitting coil (13) form a sensor array (19) which is at least partially covered by a common conductive coupling element (14) or two different conductive coupling elements (14).

14. The inductive measuring assembly (10) according to claim 13, characterized in that The at least one evaluation and control unit is further designed to receive and evaluate measurement signals (MS) induced in a plurality of coil pairs (18) of the at least one receiving structure (16) and to determine the spatial position of the movable body (3) based on the evaluation.

15. A pedal assembly (1) for a vehicle, comprising: at least one movably supported pedal (3A), which can be operated over a predetermined axial operating stroke against the force of at least one spring element (15); and at least one inductive measuring assembly (10), which is constructed according to any one of claims 1 to 14 and is implemented to detect the operation of the pedal (3A) and the corresponding operating stroke.

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