Inductive sensor assembly for detecting movement of moving body
By optimizing coverage and receiver structure design, the sensing sensor assembly reduces measurement errors, improves signal-to-noise ratio and electromagnetic compatibility, and reduces structural space and cost when detecting motion.
Patent Information
- Application Number
- CN202510438802.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-04-11
- Filing Date
- 2025-04-09
- Publication Date
- 2025-10-21
AI Technical Summary
Existing sensing sensor components suffer from problems such as large measurement errors, low signal-to-noise ratio, large structural space, and high cost when detecting motion.
By optimizing coverage and receiver structure design, selecting coverage in the range of 0.7 to 0.8, and using receiver coils and evaluation units arranged 180° apart, the induced voltage is increased and the measurement error is reduced. Inexpensive semiconductor amplifiers and smaller structural space are also employed.
It achieves smaller measurement errors, improves signal-to-noise ratio and electromagnetic compatibility, reduces structural space and cost, and increases the amplitude of induced voltage.
Smart Images
Figure CN120820176A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an inductive sensor assembly for detecting motion of a moving subject. Background Art
[0002] Known in the prior art are inductive sensor assemblies used as rotational motion sensors for detecting rotational motion or linear displacement sensors for detecting linear motion. Such inductive sensor assemblies include a measured value acquisition device and at least one coupling device, which has at least one exciter structure and at least one receiving structure, also referred to as a target. The measured value acquisition device or at least one coupling device is coupled to a moving body. Furthermore, at least one exciter structure includes at least one excitation coil. At least one coupling device includes at least one electrically conductive coupling section. At least one receiving structure includes at least one, but typically two, receiving coils. A high-frequency current flows through the at least one excitation coil, generating an alternating magnetic field that induces eddy currents in the at least one coupling device. The inductive coupling between the at least one excitation coil and the at least one receiving coil is correlated with the position of the corresponding coupling device. The voltage signal induced in the at least one receiving coil allows inferences to be drawn about the current position of the coupling device and, therefore, the current position of the body whose motion is to be detected. Summary of the Invention
[0003] The inductive sensor assembly for detecting the motion of a moving body according to the present invention has the advantage that by selecting a coverage ratio, which is calculated based on the coverage of at least one conductive coupling segment in the direction of motion relative to a periodic section of at least one receiving structure, the measurement error of the measurement signal can be minimized and the amplitude of the measurement signal can be maximized. Consequently, embodiments of the inductive sensor assembly according to the present invention can increase the voltage induced in the at least one receiving structure and the amplitude of the resulting measurement signal, while simultaneously reducing the measurement error of the measured value acquisition device or the inductive sensor assembly. For example, angular errors can be reduced when detecting rotational motion, and displacement errors can be reduced when detecting linear motion. Lower measurement errors enable a smaller installation space and eliminate the need for harmonic correction. A higher amplitude of the measurement signal leads to a better signal-to-noise ratio and improved electromagnetic compatibility (EMC). Furthermore, a higher amplitude of the measurement signal enables a larger air gap, thereby reducing costs in the mechanical device. Furthermore, a higher amplitude of the measurement signal enables the use of less expensive semiconductor amplifiers with reduced amplification factors.
[0004] Embodiments of the present invention provide an inductive sensor assembly for detecting the motion of a moving body, comprising at least one measured value acquisition device and at least one coupling device, the measured value acquisition device including at least one exciter structure and at least one receiving structure. The at least one measured value acquisition device or the at least one coupling device is coupled to the moving body. At least one evaluation and control unit is configured to couple a periodic alternating signal into the at least one exciter structure during operation, evaluate the signal induced in the at least one receiving structure, and determine a measurement signal indicating the current position of the moving body. The at least one coupling device includes a base body having at least one electrically conductive coupling section and is configured to influence inductive coupling between the at least one exciter structure and the at least one receiving structure. A coverage factor, calculated based on a resulting measurement error and a resulting amplitude of the measurement signal relative to a periodic section of the at least one receiving structure, is selected such that the resulting measurement error of the measurement signal is below a predetermined first threshold value, present at a coverage factor of 0.5, and the resulting amplitude exceeds a predetermined second threshold value, depending on the type of structure.
[0005] The inductive sensor assembly can be implemented as a rotation angle sensor or a rotor position sensor, for example, wherein the moving body performs a rotational movement to be detected about the rotation axis. Alternatively, the inductive sensor assembly can be implemented as a linear displacement sensor, wherein the moving body performs a linear movement to be detected.
[0006] In the present context, an evaluation and control unit can be understood as an electrical component or circuit that prepares, processes, or evaluates detected sensor signals. Preferably, the evaluation and control unit can be implemented as an ASIC (Application-Specific Integrated Circuit). The evaluation and control unit can have at least one interface, which can be implemented as hardware and / or software. In a hardware-based design, the interface can, for example, be part of an ASIC. However, it is also possible for the interface to be a separate integrated circuit or to be composed at least partially of separate components. In a software-based design, the interface can be a software module, for example, located on a microcontroller alongside other software modules.
[0007] The exciter structure can then be understood to mean an exciter coil having a predetermined number of turns, which emits an alternating signal coupled in from at least one oscillator circuit.
[0008] The inductive sensor assembly according to the invention can be advantageously improved by means of the measures and developments listed in the description.
[0009] It is particularly advantageous that the at least one receiving structure may include at least one receiving coil having at least one turn with two periodically repeating winding structures. The two winding structures of each turn are arranged 180° apart from one another. This allows for a particularly cost-effective and simple implementation of the at least one receiving structure. A periodic section of the at least one receiving structure may correspond to a complete period of the periodically repeating winding structure of the at least one receiving coil. Preferably, the at least one receiving structure may include two receiving coils arranged 90° apart from one another, such that the first receiving coil forms a sine channel and the second receiving coil forms a cosine channel. Furthermore, the at least one evaluation and control unit may be configured to determine a measurement signal from the signals of the sine channel and the cosine channel using an inverse tangent function. Alternatively, the receiving structure may include three receiving coils with periodically repeating winding structures, the receiving coils forming a multi-phase system. The at least one evaluation and control unit may be configured to perform a suitable phase transformation of the signals of the multi-phase system and determine the measurement signal using an inverse tangent function. Thus, the signals of the three-phase system can be converted into two signals, for example, using a Clarke transformation, from which the measurement signal can then be determined using the inverse tangent function.
[0010] In another advantageous embodiment of the inductive sensor assembly, the coverage factor can be selected from a range of 0.7 to 0.8, preferably from a range of 0.7 to 0.75. The range of 0.7 to 0.75 can particularly combine the advantages of low measurement errors and high amplitudes of the induced voltage and the corresponding measurement signal. Generally, when the coverage factor is greater than 0.75, the amplitude of the induced voltage may decrease again, while the measurement error may also increase. Therefore, the coverage factor is no longer advantageous, especially in a range greater than 0.8. When the coverage factor is less than 0.7, the angular error may generally increase, and the amplitude of the induced voltage may decrease. Therefore, in particular, the coverage factor is no longer advantageous in a range of less than 0.6. When the coverage factor is in the range of 0.3 to 0.4, additional local minimums of the measurement error can be provided, depending on the type of construction. However, the amplitude of the induced voltage is significantly lower here than in the range between 0.7 and 0.8.
[0011] In another advantageous embodiment of the inductive sensor assembly, a structure-type-dependent second threshold value for the coverage ratio and / or the generated amplitude of the measurement signal can be predefined as a function of the air gap between the at least one coupling device and the at least one receiving structure and / or as a function of the periodicity of the at least one receiving structure and / or as a function of the geometry of the at least one receiving structure. This advantageously makes it possible to predefine the coverage ratio and / or the second threshold value as a function of the mechanical design of the inductive sensor assembly.
[0012] In another advantageous embodiment of the inductive sensor assembly, the two winding structures of at least one turn of at least one receiving coil can each have a plurality of winding sections and be arranged in at least two planes of the circuit carrier with opposite flow directions. The sections of the respective winding structures arranged in different planes of the circuit carrier can be electrically connected to one another via plated-through holes.
[0013] In another advantageous embodiment of the inductive sensor assembly, the moving body can perform a rotational motion about an axis of rotation, wherein the measurement error corresponds to an angular error. To detect the rotational motion of the moving body about the axis of rotation, at least one coupling device can include a base body embodied as a rotor. Here, at least one electrically conductive coupling segment can be embodied as a wing and connected to the base body embodied as a rotor. In this embodiment of the at least one coupling device, the footprint of the at least one electrically conductive coupling segment in the direction of motion can correspond to a circular arc or a circular ring segment.
[0014] Alternatively, the moving body can perform linear motion, wherein the measurement error corresponds to a displacement error. To detect the linear motion of the moving body, at least one coupling device can include a substrate configured as a carrier. Here, at least one electrically conductive coupling segment can be configured as a surface and arranged on the substrate configured as a carrier. In this embodiment of the at least one coupling device, the footprint of the at least one electrically conductive coupling segment in the direction of motion can correspond to a straight line or a rectangle. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Embodiments of the present invention are shown in the drawings and explained in more detail in the following description.In the drawings, the same reference numerals represent components or elements that implement the same or similar functions.
[0016] Figure 1 A schematic diagram shows a first embodiment of an inductive sensor assembly for detecting motion of a moving subject according to the present invention.
[0017] Figure 2 Shown Figure 1 Schematic top view of an inductive sensor assembly according to the invention with a transparently illustrated coupling device.
[0018] Figure 3 A schematic top view of a second exemplary embodiment of an inductive sensor assembly according to the invention is shown with a transparently illustrated coupling device.
[0019] Figure 4 A schematic characteristic curve diagram is shown, which has two characteristic curves respectively showing the measurement error-coverage ratio variation of the inductive sensor assembly according to the present invention and a characteristic curve showing the amplitude-coverage ratio variation of the inductive sensor assembly according to the present invention. DETAILED DESCRIPTION
[0020] from Figures 1 to 3 As can be seen, the illustrated exemplary embodiment of an inductive sensor assembly 1 according to the present invention for detecting the movement of a moving body 3 each includes at least one measured value acquisition device 10 and at least one coupling device 20, each comprising at least one exciter structure 14 and at least one receiving structure 16. The at least one measured value acquisition device 10 or the at least one coupling device 20 is coupled to the moving body 3. Furthermore, at least one evaluation and control unit 5 is designed to couple a periodic alternating signal into the at least one exciter structure 14 during operation, evaluate the signal induced in the at least one receiving structure 16, and determine a measurement signal MS for the current position of the moving body 3. The at least one coupling device 20 has a base body 22 with at least one electrically conductive coupling section 24 and is designed to influence the inductive coupling between the at least one exciter structure 14 and the at least one receiving structure 16. A coverage factor UV (calculated as a function of a coverage dimension UB of at least one conductive coupling segment 24 in the direction of movement BR relative to a periodic section PA of at least one receiving structure 16) is selected based on the resulting measurement error MF and the resulting amplitude AM of the measurement signal MS such that the resulting measurement error MF of the measurement signal MS is below a preset first threshold value SW1 present at a coverage factor UV of 0.5 and the resulting amplitude AM exceeds a preset second threshold value SW2 that depends on the type of structure.
[0021] In the illustrated embodiment of inductive sensor assembly 1 , evaluation and control unit 5 outputs measurement signals to a superordinate control unit 7 , which evaluates the measurement signals in order to actuate corresponding vehicle functions.
[0022] As especially from Figure 2 and Figure 3 As can be further seen in the figure, the illustrated embodiment of the inductive sensor assembly 1 each includes a circuit carrier 12 having an exciter structure 14 and a receiving structure 16. In the illustrated embodiment of the inductive sensor assembly 1, the exciter structure includes an exciter coil 14A having turns arranged in two planes of the circuit carrier 12; the receiving structure includes receiving coils 16A, 16B having turns W1, W2. Each turn W1, W2 of the two receiving coils 16A, 16B each includes two periodically repeating coil structures 18A, 18B. The two coil structures 18A, 18B of each turn W1, W2 are arranged 180° offset from one another.
[0023] As from Figure 2 and Figure 3As can also be seen in the figure, the two winding structures 18A, 18B of the individual turns W1, W2 of the two receiving coils 16A, 16B each have a plurality of winding sections that are arranged in at least two planes of the circuit carrier 12 and have opposite flow directions. The sections of the respective winding structures 18A, 18B arranged in different planes of the circuit carrier 12 are electrically connected to one another via plated-through holes DK. Furthermore, the periodic sections PA of the illustrated receiving structure 16 each correspond to a complete period XP of the periodically repeating winding structures 18A, 18B of the two receiving coils 16A, 16B.
[0024] As from Figure 4 As can further be seen, the characteristic diagram shown shows two characteristic curves K1 , K2 each showing by way of example the course of the measurement error MF of the measurement signal MS over the coverage UV, and a third characteristic curve K3 showing by way of example the course of the amplitude AM of the measurement signal MS over the coverage UV.
[0025] As from Figure 4 As can be further seen in FIG, the first threshold value SW1 for the measurement error MF corresponds to the value of the measurement error MF at a coverage factor of 0.5. In embodiments of the inductive sensor assembly 1, the coverage factor UV is selected in the range of 0.7 to 0.8. The range of 0.7 to 0.75 combines the advantages of a low measurement error MF and a high amplitude AM of the induced voltage or corresponding measurement signal MS.
[0026] As from Figure 4 As can be further seen, particularly in the configuration represented by the second characteristic curve K2, when the coverage factor UV exceeds 0.72, the amplitude of the induced voltage or measurement signal MS increases further, while the measurement error MF increases significantly further. Therefore, particularly in the configuration represented by the second characteristic curve K2, the coverage factor UV is no longer favorable in a range greater than 0.8. At a coverage factor less than 0.7, particularly in the configuration represented by the first characteristic curve K1, the angular error may increase, and the amplitude AM of the induced voltage or measurement signal MS may decrease. Therefore, particularly in the configuration represented by the first characteristic curve K1, the coverage factor UV is no longer favorable in a range less than 0.6. Depending on the configuration, a coverage factor UV in the range of 0.3 to 0.4, particularly in the configuration represented by the second characteristic curve K2, may provide additional local minima of the measurement error MS. However, in this case, the amplitude AM of the induced voltage or measurement signal MS is significantly lower than in the range between 0.7 and 0.8.
[0027] The coverage factor UV and / or the structure-type-dependent second threshold value SW2 of the generated amplitude AM of the measurement signal MS is predetermined as a function of the air gap between the at least one coupling device 20 and the at least one receiving structure 16, and / or as a function of the periodicity of the at least one receiving structure 16, and / or as a function of the geometry of the at least one receiving structure 16. In the exemplary embodiment shown, the predetermined coverage factor UV each has a value of 0.72.
[0028] As from Figure 1 and Figure 2 As can be seen further in FIG, the illustrated first embodiment of the inductive sensor assembly 1 is implemented as a rotational motion sensor 1A. The moving body 3 therefore executes a rotational motion about an axis of rotation DA, wherein the measurement error MF corresponds to an angular error.
[0029] As from Figure 1 and Figure 2 As can be further seen, in the illustrated embodiment of the rotary motion sensor 1A, the coupling device 20A includes a base body 22 designed as a rotor 22A, since the moving body 3 performs a rotational motion about the rotation axis DA. Here, at least one electrically conductive coupling segment 24 is designed as a wing 24A and is connected to the base body 22 designed as a rotor 22A. This means that in the illustrated embodiment of the rotary motion sensor 1A, the footprint UB of the electrically conductive coupling segment 24 in the direction of motion BR corresponds to a circular ring segment, which covers only a portion of the periodic section PA of the illustrated receiving structure 16 or a complete period XP of the periodically repeating winding structures 18A, 18B of the two receiving coils 16A, 16B in the direction of motion BR, leaving a free, uncovered segment FB in the direction of motion BR. In the illustrated embodiment, the entire wing 24A forms a circular ring segment. In an alternative, not illustrated, embodiment of the rotary motion sensor 1A, the footprint UB of the electrically conductive coupling segment 24 in the direction of motion BR may only cover a portion of the wing 24A. In an extreme case, the footprint UB of the electrically conductive coupling section 24 in the direction of movement BR can only correspond to the arc of a circle attached to the wing 24A.
[0030] As from Figure 3 As can be seen further in FIG, the illustrated embodiment of the inductive sensor assembly 1 is implemented as a linear displacement sensor 1B. Therefore, the moving body, not shown in detail here, performs a linear movement, wherein the measurement error MF corresponds to the displacement error.
[0031] As from Figure 3As can be further seen in the figure, in the illustrated embodiment of the linear displacement sensor 1B, the coupling device 20B has a base 22 embodied as a carrier 22B, since the moving body 3 performs a linear motion. Here, at least one electrically conductive coupling segment 24 is embodied as a surface 24B and is arranged on the base 22 embodied as the carrier 22B. This means that in the illustrated embodiment of the linear displacement sensor 1B, the footprint UB of the electrically conductive coupling segment 24 in the direction of motion BR corresponds to a rectangular surface 24B that covers only a portion of the periodic section PA of the illustrated receiving structure 16 or a portion of the complete period XP of the periodically repeating coiled structures 18A, 18B of the two receiving coils 16A, 16B in the direction of motion BR, leaving a free, uncovered segment FB in the direction of motion BR. In the illustrated embodiment, the rectangular surface 24B covers a portion of the carrier 22B. In alternative, not illustrated, embodiments of the linear displacement sensor 1B, the footprint UB of the electrically conductive coupling segment 24 in the direction of motion BR may cover a larger or smaller portion of the carrier 22B. In the extreme case, the footprint UB of the electrically conductive coupling section 24 in the direction of movement BR may correspond only to a straight line arranged on the carrier 22B.
Claims
1. An inductive sensor assembly (1) for detecting a movement of a moving body (3), the inductive sensor assembly comprising at least one measured value detection device (10) and at least one coupling device (20), the measured value detection device comprising at least one actuator structure (14) and at least one receiving structure (16), wherein: The at least one measured value detection device (10) or the at least one coupling device (20) is coupled to the moving body (3), wherein at least one evaluation and control unit (5) is implemented to couple a periodic alternating signal into the at least one exciter structure (14) during operation and to evaluate the signal induced in the at least one receiving structure (16) and to determine a measurement signal (MS) for the current position of the moving body (3), wherein the at least one coupling device (20) comprises a base body (22) having at least one electrically conductive coupling section (24) and is implemented to influence the at least one exciter structure (14) and the at least one receiving structure (16). The invention relates to an inductive coupling between a receiving structure (16) and a measuring signal (MS), wherein a coverage factor (UV) is selected as a function of a generated measurement error (MF) and a generated amplitude (AM) of the measuring signal (MS) such that the generated measurement error (MF) of the measuring signal (MS) is below a preset first threshold value (SW1) present at a coverage factor (UV) of 0.5 and the generated amplitude (AM) exceeds a preset second threshold value (SW2) depending on the type of structure, the coverage factor being calculated as a function of a coverage dimension (UB) of the at least one electrically conductive coupling section (24) in a direction of movement (BR) relative to a periodic section (PA) of the at least one receiving structure (16).
2. The inductive sensor assembly (1) according to claim 1, characterized in that The at least one receiving structure (16) includes at least one receiving coil (16A, 16B) having at least one turn (W1, W2) with two periodically repeated winding structures (18A, 18B).
3. The inductive sensor assembly (1) according to claim 2, characterized in that A periodic section (PA) of the at least one receiving structure (16) corresponds to a complete period (XP) of the periodically repeating coiled structure (18A, 18B) of the at least one receiving coil (16A, 16B).
4. The inductive sensor assembly (1) according to any one of claims 1 to 3, characterized in that The coverage (UV) is selected from the range of 0.7 to 0.8, preferably from the range of 0.7 to 0.
75.
5. The inductive sensor assembly (1) according to any one of claims 1 to 4, characterized in that A second structure-type-dependent threshold value (SW2) of the coverage (UV) and / or the resulting amplitude (AM) of the measurement signal (MS) is preset as a function of the air gap between the at least one coupling device (20) and the at least one receiving structure (16) and / or as a function of the periodicity of the at least one receiving structure (16) and / or as a function of the geometry of the at least one receiving structure (16).
6. The inductive sensor assembly (1) according to any one of claims 2 to 5, characterized in that The two winding structures (18A, 18B) of at least one turn (W1, W2) of the at least one receiving coil (16A, 16B) each have a plurality of winding sections and are constructed in at least two planes of the circuit carrier (12) and have opposite flow directions.
7. The inductive sensor assembly (1) according to claim 6, characterized in that Sections of the respective coil structures (18A, 18B) arranged in different planes of the circuit carrier (12) are electrically connected to one another via plated-through holes (DK).
8. The inductive sensor assembly (1) according to any one of claims 1 to 7, characterized in that The moving body (3) performs a rotational movement about a rotation axis (DA), in which the measurement error (MF) corresponds to an angular error, or the moving body (3) performs a linear movement, in which the measurement error (MF) corresponds to a displacement error.
9. The inductive sensor assembly (1) according to claim 8, characterized in that When the moving body (3) performs a rotational movement about an axis of rotation (DA), the at least one coupling device (20) has a base body (22) designed as a rotor (22A).
10. The inductive sensor assembly (1) according to claim 9, characterized in that The at least one electrically conductive coupling section (24) is embodied as a wing (24A) and is connected to a base body (22) embodied as a rotor (22A).
11. The inductive sensor assembly (1) according to claim 9, characterized in that When the moving body (3) performs a linear movement, the at least one coupling device (20) has a base body (22) which is implemented as a carrier (22B).
12. The inductive sensor assembly (1) according to claim 11, characterized in that The at least one electrically conductive coupling section (24) is embodied as a surface (24B) and is arranged on a base body (22) embodied as a carrier (22B).