An inductive sensor, a sensing system and a terminal device

Abstract

The application relates to the technical field of inductive sensors, in particular to an inductive sensor, a sensing system and a terminal device. The inductive sensor comprises an oscillator circuit, an excitation coil connected with the oscillator circuit, N receiving coils coaxially arranged with the excitation coil, and a signal processing circuit connected with the N receiving coils. At least the inductive sensor can improve the measurement precision and accuracy without modifying the measurement results by means of filtering algorithms or compensation algorithms.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inductive sensors, and particularly relates to an inductive sensor, a sensing system and a terminal device. BACKGROUND

[0002] An inductive sensor is a device for realizing non-electricity measurement by using the change of self-inductance or mutual inductance. By using the inductive sensor, displacement, pressure, vibration, strain, flow and other parameters can be measured. The inductive sensor has a series of advantages such as simple structure, high sensitivity, large output power, small output impedance, strong anti-interference ability and high measurement precision, and is therefore widely used in electromechanical control systems.

[0003] However, the current inductive sensor measurement has deviation and low precision. SUMMARY

[0004] The inductive sensor, the sensing system and the terminal device provided in the embodiments of the present application are at least beneficial to improving the measurement precision and accuracy of the inductive sensor without relying on correction of measurement results by filtering algorithms or compensation algorithms.

[0005] According to some embodiments of the present application, the first aspect of the embodiments of the present application provides an inductive sensor, comprising: an oscillator circuit; an excitation coil connected with the oscillator circuit; N receiving coils coaxially arranged with the excitation coil, and each receiving coil in the N receiving coils is sequentially staggered around the axis a signal processing circuit connected with the N receiving coils.

[0006] In some embodiments, the value range of N is wherein, W r = r out -r in , r in is the inner radius of the N receiving coils, r out is the outer radius of the N receiving coils, p = ω min +s min , ω min is the minimum line width allowed on the substrate where the N receiving coils are located, s min is the minimum line distance allowed on the substrate where the N receiving coils are located, n layersm is the number of layers of the medium layer available for deploying the N receiving coils on the substrate where the N receiving coils are located, m is 1 when the N receiving coils have no backflow, or have backflow but the backflow does not run from the medium layer where the N receiving coils are located, m is 2 when the N receiving coils have backflow and the backflow runs from the medium layer where the N receiving coils are located, and a is a preset protection coefficient.

[0007] In some embodiments, N≥N', and N' is the maximum order of the harmonic generated by the inductive sensor.

[0008] In some embodiments, the signal processing circuit includes an input interface, a signal processing sub-circuit, and an output interface connected in sequence, and the input interface is connected to each of the N receiving coils respectively.

[0009] In some embodiments, the signal processing sub-circuit includes a lookup table and a multiplier-accumulator; the input interface, the lookup table, the multiplier-accumulator, and the output interface are connected in sequence, and the input interface and the lookup table are connected through N signal channels; wherein the lookup table stores rotation coefficients for mapping N signals generated by the N receiving coils or digital signals corresponding to the N signals into M orthogonal signals, and M is a positive integer.

[0010] In some embodiments, the signal processing sub-circuit includes M multiplier-accumulators, and each of the M multiplier-accumulators is connected to the output interface.

[0011] In some embodiments, M=2.

[0012] In some embodiments, the excitation coil and / or the N receiving coils are arranged on a PCB board.

[0013] According to some embodiments of the present application, the second aspect of the embodiments of the present application further provides an inductive sensing system, including: the inductive sensor according to any one of the first aspect, and a host computer connected to the inductive sensor; wherein the host computer is configured to acquire and process signals and / or data output by the signal processing circuit in the inductive sensor.

[0014] According to some embodiments of the present application, the third aspect of the embodiments of the present application further provides a terminal device, including: the inductive sensor according to any one of the first aspect, or the inductive sensing system according to the second aspect.

[0015] The technical solutions provided in the embodiments of the present application have at least the following advantages:

[0016] The inductive sensor is provided with coils that are sequentially staggered around the axis N receiving coils, so that the high-order harmonics can be effectively suppressed among the signals generated on the N receiving coils, thereby reducing the interference of the harmonics on the measurement results without depending on the correction of the measurement results by filtering algorithms or compensation algorithms, and improving the accuracy and precision of the measurement. BRIEF DESCRIPTION OF DRAWINGS

[0017] One or more embodiments are illustrated by way of example in the figures that are part of this disclosure and which are illustrative, but not restrictive, of the embodiments, wherein elements having the same reference numerals designate like elements throughout the several views, and wherein the figures are not necessarily to scale, unless otherwise specifically noted.

[0018] Figure 1 is a structural schematic diagram of an inductive sensor provided in an embodiment of the present application;

[0019] Figure 2 is a coil pattern schematic diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=3;

[0020] Figure 3 is a phase distribution diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=3;

[0021] Figure 4 is a coil pattern schematic diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=4;

[0022] Figure 5 is a phase distribution diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=4;

[0023] Figure 6 is a coil pattern schematic diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=5;

[0024] Figure 7 is a phase distribution diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=5;

[0025] Figure 8 is a coil pattern schematic diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=6;

[0026] Figure 9 is a phase distribution diagram of N receiving coils of an inductive sensor provided in another embodiment of the present application when N=6;

[0027] Figure 10 is a structural schematic diagram of an inductive sensor provided in another embodiment of the present application;

[0028] Figure 11 is a structural schematic diagram of an inductive sensor provided in another embodiment of the present application. DETAILED DESCRIPTION

[0029] As can be known from the background, the current inductive sensor measurement has deviation and low precision.

[0030] It is found through analysis that the reason for the above problems is that the coil in the inductive sensor may introduce non-ideal errors in physical characteristics such as the number of turns, shape, phase asymmetry, etc. of the coil, thereby generating high-order harmonics such as third-order harmonics, fifth-order harmonics, etc. When the receiving coil generates an output signal, it is inevitably affected by these harmonic signals, thereby causing distortion of the signal in the transmission process. In the receiving coil scheme commonly used in the related art, the two-phase 90° equally spaced wiring ultimately affects the measurement precision of the inductive sensor. For example, it causes signal distortion, and the superposition of harmonic components and fundamental waves affects the accuracy of measurement, which may cause deviation in the angle calculation result. Also, it causes the angle error to increase, and the interference of high-order harmonic frequency components makes the angle estimation of the sensor inaccurate, especially in a dynamic scenario, the system is difficult to maintain high precision.

[0031] At the same time, although the influence of harmonics can be corrected from the algorithm point of view, the existing signal processing method cannot completely eliminate the interference of high-order harmonics, and more complex filtering algorithm or compensation algorithm, etc. is needed to correct, so as to increase the complexity of calculation and response time. It will not only increase the cost, but also increase the implementation difficulty.

[0032] Therefore, in order to solve the problem of precision reduction caused by high-order harmonic interference without relying on filtering algorithm or compensation algorithm, etc. to correct the measurement result, an inductive sensor, a sensing system and a terminal device are provided in the embodiments of the present application. By arranging N receiving coils which are sequentially staggered around the axis, the high-order harmonic parts in the signals on the N receiving coils cancel each other out, effectively suppressing the high-order harmonics, thereby improving the calculation precision of the inductive sensor without relying on filtering algorithm or compensation algorithm, etc. to correct the measurement result, and realizing higher precision measurement.

[0033] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be realized even without these technical details and various changes and modifications based on the following embodiments.

[0034] The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific implementation modes of the present application. The various embodiments can be combined with each other and referenced to each other without contradiction.

[0035] The first aspect of the embodiments of the present application provides an inductive sensor, the structure of which is shown in Figure 1 The inductive sensor comprises:

[0036] an oscillator circuit 100;

[0037] an excitation coil 200 connected with the oscillator circuit 100;

[0038] N receiving coils 300 coaxially arranged with the excitation coil 200, and each receiving coil 301 in the N receiving coils 300 is sequentially staggered around the axis

[0039] a signal processing circuit 400 connected with the N receiving coils 300.

[0040] Therefore, after the alternating current signal generated by the oscillator circuit 100 is output to the excitation coil 200, an electromagnetic field will be generated based on electromagnetic induction. When the rotor exists in the electromagnetic field, the rotor will react to the electromagnetic field and change the electromagnetic field based on the induction effect, so that the N receiving coils 300 generate an induction signal based on the changed electromagnetic field and output it to the signal processing circuit 400. The signal processing circuit 400 processes and outputs the induction signal. In this process, the reaction effect of the rotor on the electromagnetic field changes with the movement of the rotor, so the induction signal also changes. Therefore, by analyzing the output of the signal processing circuit 400, the movement process of the rotor can be measured, that is, the physical quantity (such as displacement, angle, etc.) in the movement of the rotor can be measured. Since each receiving coil 301 in the N receiving coils 300 is sequentially staggered around the axis so that the induction signals generated on the receiving coils 301 act on each other and cancel at least part of the high-order harmonic signals, realizing the suppression of high-order harmonic signals, thereby reducing the interference of high-order harmonics on the measurement results without relying on correction of the measurement results such as filtering algorithm or compensation algorithm, and improving the accuracy and precision of the measurement.

[0041] In order to facilitate understanding of the above high-order harmonic suppression effect, the induction signals generated on each receiving coil 301 in the N receiving coils 300 will be mapped to the αβ plane as the output signal of the inductive sensor in the subsequent description.

[0042] Since each receiving coil 301 in the N receiving coils 300 is sequentially staggered around the axis Therefore, the induction signal generated on the kth coil 301 satisfies the following expression:

[0043] U k (t)=U m1 ×cos(ω×t-θ k )+∑ h [U mh ×cos(h×ω×th×θ k )];

[0044] Among them, U k (t) is a function of the induced signal generated on the k-th receiving coil 301 as a function of time t; U m1 It is the fundamental amplitude of the signal induced by the electromagnetic field; U mh It is the amplitude of the harmonic signal of order h, where h = 3, 5, 7, ..., or h = 2, 4, 6, ...; ω represents the initial phase of the induced signal on the k-th receiving coil 301, where ω is the frequency of the signal.

[0045] The output signal generated by the N receiving coils 300 as a whole can be regarded as the result of a weighted superposition of the induced signals generated by each receiving coil 301 after phase rotation. Here, the signal phase rotation can be equivalent to the signal being multiplied by e. j×θ In other words, the output signal U out (t) is:

[0046]

[0047] Thus, Euler's formula is used. After expanding the cosine, we have:

[0048]

[0049] Therefore, the output signal U out (t) can be viewed as the superposition of two components, namely the fundamental term and the harmonic term. The signal expression of the fundamental term is as follows:

[0050]

[0051] The above formula can be further expressed as:

[0052] The signal expression for the h-th harmonic component is as follows:

[0053]

[0054] exist In the middle, let p = -(h-1); in In the middle, let the corresponding p = h + 1.

[0055] So regardless still All can be represented in the following form: Here, p represents the harmonic order. Whether the harmonic signals are canceled out depends on whether the vector sum corresponding to different p values ​​is zero.

[0056] At this time, So because therefore, It is easy to see that S(p) is a standard geometric sequence. Therefore, based on the summation theorem for geometric sequences, we know that: e j×2×π×p =1.

[0057] Therefore, when p is an integer multiple of N, the denominator If p is 0, S(p) = N can be calculated using the limit method; if p is not an integer multiple of N, then S(p) = 0.

[0058] In other words, for the fundamental frequency signal There are two frequency terms: the forward rotation frequency component e. j×ω×t And, the inverted frequency component e -j×ω×t e j×ω×t and e -j×ω×t It is the time-domain representation of the waveform, ∑1 and The two sums are fittings in the waveform spatial domain, i.e., the fundamental wave and the second harmonic at different phases θ. k The superposition after rotation.

[0059] Therefore, the component e in the fundamental signal j×ω×t Multiplying by ∑1=N is equivalent to directly accumulating N e. j×ω×t The other component, e, is preserved intact. -j×ω×t Multiply The summation S(p) is calculated using a geometric series, where p = 2. If 2 is not an integer multiple of N, such as N = 3, 4, 5, ..., then S(p) = 0, meaning the vector sum is 0, and the signals cancel each other out.

[0060] Similarly, the signal of the h-th harmonic component There are also two frequency terms: forward component and forward component. And, inverted components Let p = -(h-1). If (h-1) mod N ≡ 0 and S(p) = N, then the first term remains, and the part corresponding to the forward component is retained. Let p = h+1. If (h+1) mod N ≡ 0 and S(p) = N, then the second term remains, and the part corresponding to the inverted component is retained. Otherwise, both terms cancel each other out, and after mapping to the αβ plane, the h-th harmonic part of the signal will completely disappear.

[0061] In other words, for the output signal mapped onto the αβ plane, the harmonic cancellation will be as shown in Table 1 below:

[0062] Table 1 Harmonic cancellation of N receiving coils

[0063]

[0064] Therefore, based on the above analysis and Table 1, it can be seen that when N=3, the inductive sensor can cancel all harmonics whose orders are integer multiples of 3, such as the 3rd, 6th, and 9th harmonics, effectively improving the accuracy of fundamental component extraction and enhancing the system's anti-interference capability; when N=4, the inductive sensor can cancel all harmonics whose orders are even, such as the 2nd, 4th, 6th, and 8th harmonics, which is suitable for application scenarios that require the elimination of interference from harmonics of even orders, ensuring the purity of fundamental component extraction and improving overall measurement accuracy and stability; when N=5, the inductive sensor can cancel the 5th harmonic, and simultaneously cancel the 3rd harmonic, The 7th, 9th, and 11th harmonics, which are odd-order harmonics, are significantly weakened, significantly improving signal stability in high-frequency interference environments. When N=5, it can also achieve higher angular resolution and stronger fault tolerance, making it suitable for applications with high dynamic response requirements. When N=6, the inductive sensor can cancel the 2nd, 3rd, 4th, and 6th harmonics, and weaken the 5th, 7th, and 11th harmonics, which are odd-order harmonics. While improving measurement accuracy, it effectively improves the system's resistance to high-order harmonic interference, making it suitable for high-reliability sensor designs in harsh electromagnetic environments.

[0065] Of course, N can also take other values, which will not be elaborated here.

[0066] As can be seen from the above analysis, the inductive sensor provided in this application embodiment can cancel at least some of the higher-order harmonics, reduce the interference of higher-order harmonics on the measurement results, and improve the accuracy and precision of the measurement.

[0067] To facilitate understanding of the inductive sensor provided in the embodiments of this application, its structure will be described below. As analyzed above, the suppression effect of the inductive sensor provided in the embodiments of this application on higher-order harmonics mainly comes from the cancellation of the signals generated by the N receiving coils 300. Therefore, the following description mainly focuses on the N receiving coils 300.

[0068] The following will describe, based on different values ​​of N, the sequential misalignment of each of the N receiving coils 301 around the axis described in the embodiments of this application. Provide examples and explanations.

[0069] When N=3, the shape of the 3 receiving coils 301 included in the N receiving coils 300 will be as follows: Figure 2As shown, by Figure 2 It can be seen that each receiving coil 301 is a closed coil consisting of 5 electrical cycles. Each electrical cycle is considered to be 2π. The shape of a receiving coil 301, i.e., one electrical cycle, will contain one protrusion. Within one electrical cycle of a receiving coil 301, the... Figure 2 Taking the solid line within the acute angle range formed by O1S1 and O1T1, representing one electrical cycle of the receiving coil 301, as an example, the three receiving coils 301 are evenly distributed with a phase difference of 360° / 3 = 120°. At this time, since the phase difference between any two adjacent receiving coils 301 is 120°, the phase distribution of these three receiving coils 301 will be as follows... Figure 3 As shown.

[0070] When N=4, the shape of the four receiving coils 301 included in the N receiving coils 300 will be as follows: Figure 4 As shown, by Figure 4 It can be seen that each receiving coil 301 is a closed coil consisting of 5 electrical cycles. Each electrical cycle is considered to be 2π. The shape of one receiving coil 301 is reflected in one electrical cycle, which will contain one protrusion. Within one electrical cycle of one receiving coil 301, the four receiving coils 301 are evenly distributed, with a phase difference of 360° / 4 = 90°. Since the phase difference between any two adjacent receiving coils 301 is 90°, the phase distribution of these four receiving coils 301 will be as follows: Figure 5 As shown.

[0071] When N=5, the shape of the 5 receiving coils 301 included in the N receiving coils 300 will be as follows: Figure 6 As shown, by Figure 6 It can be seen that each receiving coil 301 is a closed coil consisting of 5 electrical cycles. Each electrical cycle is considered to be 2π. The shape of one receiving coil 301 is reflected in one electrical cycle, which will contain one protrusion. Within one electrical cycle of one receiving coil 301, the 5 receiving coils 301 are evenly distributed, with a phase difference of 360° / 5 = 72°. Since the phase difference between two adjacent receiving coils 301 is 72°, the phase distribution of these 5 receiving coils 301 will be as follows: Figure 7 As shown, the phase difference between two adjacent receiving coils 301 is 72°.

[0072] When N=6, the shape of the 6 receiving coils 301 included in the N receiving coils 300 will be as follows: Figure 8 As shown, by Figure 8It can be seen that each receiving coil 301 is a closed coil consisting of 6 electrical cycles. Each electrical cycle is considered to be 2π. The shape of one receiving coil 301 is reflected in one electrical cycle, which will contain one protrusion. Within one electrical cycle of one receiving coil 301, the 6 receiving coils 301 are evenly distributed, with a phase difference of 360° / 6 = 60°. Since the phase difference between two adjacent receiving coils 301 is 60°, the phase distribution of these 6 receiving coils 301 will be as follows... Figure 9 As shown.

[0073] Of course, the above are just examples. In some embodiments, N can take other values, which will not be listed here.

[0074] In some embodiments, the value of N ranges from [3, ..., ],in, , , , , , It is the inner radius of N receiving coils, each with a diameter of 300. It is the outer radius of N receiving coils, each with a diameter of 300. , It is the minimum allowable linewidth on the substrate where N receiving coils 300 are located. It is the minimum allowable line spacing on the substrate where N receiving coils 300 are located. Let m be the number of dielectric layers on the substrate where the N receiving coils 300 are located, which can be used to deploy the N receiving coils 300. Let m be the number of parallel channels per row of the N receiving coils. When the N receiving coils have no return current, or when there is return current but the return current does not run through the dielectric layer where the N receiving coils are located, m=1. When the N receiving coils have return current and the return current runs through the dielectric layer where the N receiving coils are located, m=2. This is the preset protection factor. At this point, the value of N is limited to no more than [a certain value]. This design ensures that the pattern of the N coils 300 is not too dense or complex, facilitating the production of N coils 300. In particular, it allows for the use of easy-to-implement and quick processes to produce N coils 300, which helps control costs and facilitates production. At the same time, interference between the individual receiving coils 301 can be effectively controlled.

[0075] In some embodiments, N is related to the order of the harmonics generated by the inductive sensor. As analyzed above, different values ​​of N result in different suppression effects on harmonics of different orders. For example, when N=3, it can cancel harmonics of orders that are multiples of 3, such as the 3rd, 6th, and 9th harmonics. When N=4, it can cancel harmonics of orders that are even, such as the 2nd, 4th, 6th, and 8th harmonics. Therefore, associating the value of N with the order of the harmonics generated by the inductive sensor allows for effective cancellation of the harmonics generated by the inductive sensor. This not only cancels higher-order harmonics but also avoids the N receiving coils 300 from becoming excessively complex. This effectively controls the complexity of the N receiving coils 300, reduces costs and implementation difficulty, and is beneficial for applications.

[0076] In some embodiments, such as Figure 10 As shown, the signal processing circuit 400 includes an input interface 401, a signal processing sub-circuit 402, and an output interface 403 connected in sequence. The input interface 401 is connected to each of the N receiving coils 300. Therefore, the induced signals generated on each of the N receiving coils 301 can be output to the input interface 401 respectively, ensuring that the induced signals generated on each of the N receiving coils 301 are output independently without affecting or interfering with subsequent signal processing.

[0077] In some embodiments, such as Figure 11 As shown, the signal processing sub-circuit 402 includes a lookup table 412 and a multiply-accumulate (MAC) unit 422. The input interface 401, lookup table 412, multiply-accumulate unit 422, and output interface 403 are connected sequentially. The input interface 401 and the lookup table 412 are connected via N signal channels. The lookup table 412 stores rotation coefficients that map the N signals or their corresponding digital signals generated by the N receiving coils 300 into M orthogonal signals, where M is a positive integer. Thus, the induced signal generated by each of the N receiving coils 301 can be independently input into the lookup table 412 after passing through the input interface 401 to determine the rotation coefficient corresponding to each signal. This coefficient is then used for rotation mapping in the multiply-accumulate unit 422, thereby mapping the N signals generated by the N receiving coils 300 into M orthogonal signals. Furthermore, different rotation coefficients can be written into the lookup table 412 to adapt to different mapping requirements, demonstrating strong versatility.

[0078] The rotation coefficients stored in lookup table 412 will vary depending on the values ​​of N and M. For example, with M=2, the rotation coefficients stored in lookup table 412 can be expressed as... Determine, where k = 0, ..., N-1.

[0079] For example, when N=4 and M=2, the rotation coefficients stored in table 412 can be looked up as shown in Table 2 below.

[0080] Table 2 Rotation Coefficients (N=4, M=2)

[0081]

[0082] When N=5 and M=2, the rotation coefficients stored in Table 412 can be found as shown in Table 3 below.

[0083] Table 3 Rotation Coefficients (N=5, M=2)

[0084]

[0085] When N=6 and M=2, the rotation coefficients stored in Table 412 can be found as shown in Table 4 below.

[0086] Table 4 Rotation Coefficients (N=6, M=2)

[0087]

[0088]

[0089] Accordingly, the processing performed on multiply-accumulator 422 can be represented by the following expression:

[0090]

[0091] Where α and β are the output signals of multiply-accumulate unit 422, which can then be used as IQ (in-phase-quadrature) signals for phase calculation, phase-locking, coordinate transformation, and other processing steps to obtain measured values ​​such as angles and displacements; x k The induced signal output from the k-th coil out of N receiving coils; This refers to the rotation coefficients output from the aforementioned lookup table 412.

[0092] In some embodiments, such as Figure 11 As shown, the signal processing sub-circuit 402 may include M multiply-accumulators 422, and each of the M multiply-accumulators 422 is connected to the output interface 403. This allows each multiply-accumulator 422 to process the mapping of one of the M orthogonal signals, thus enabling the M multiply-accumulators 422 to complete the rotation mapping in parallel and output M orthogonal signals. In particular, it can support a pipelined architecture, achieving high throughput, low latency signal processing, and higher processing efficiency.

[0093] In some embodiments, such as Figure 11As shown, M=2, meaning that the signal processing sub-circuit 402 can include two multiply-accumulators 422. Thus, the signal processing sub-circuit 402 can provide users with two orthogonal signals, which is more suitable for current algorithms for measuring displacement, angle and other information using inductive sensors, without the need for additional processing of the output signal, resulting in a better user experience.

[0094] It should be noted that the embodiments in this application are not merely illustrative examples of the signal processing circuit 400 and the signal processing sub-circuit 502. In some embodiments, the signal processing circuit 400 may not include the input interface 401, and the N coils 300 may be directly connected to the signal processing sub-circuit 402. Alternatively, in some embodiments, the signal processing sub-circuit 402 may include some signal processing engines to directly output measurement results, such as physical quantities like displacement and angle. These will not be elaborated further here.

[0095] It should also be noted that the embodiments of this application do not limit the deployment method of the relevant structures in the inductive sensor. For example, in some embodiments, the excitation coil and / or N receiving coils are disposed on a PCB (Printed Circuit Board), although other substrates may also be used, which will not be listed here. Furthermore, taking the excitation coil 200 and N receiving coils 300 disposed on a PCB as an example, in some embodiments, the excitation coil 200 and N receiving coils 300 are disposed on different layers of the PCB, etc., which will not be elaborated further here.

[0096] Furthermore, the implementation of the oscillator circuit 100 and the excitation coil 200 in this application embodiment is not limited. The oscillator circuit 100 can be any structure capable of generating alternating current, and the excitation coil 200 can be any structure capable of generating an electromagnetic field covering N receiving coils 300 based on alternating current. These will not be described in detail here.

[0097] It should be noted that the above schematic diagram of the inductive sensor structure only uses N=6 and M=2 as an example. However, this does not mean that N can only take the value of 6 and M can only take the value of 2. As mentioned earlier, different specific values ​​can be set for N and M according to the application scenario, user needs, etc., which will not be listed here.

[0098] A second aspect of this application also provides an inductive sensing system, including: an inductive sensor as described in any of the preceding embodiments, and a host computer connected to the inductive sensor; wherein the host computer is used to acquire and process signals and / or data output by the signal processing circuit in the inductive sensor.

[0099] It should be noted that the embodiments of this application do not limit the host computer. In some embodiments, the host computer may be a related signal processing chip, which may be integrated with the inductive sensor as a single device, or it may be set up independently of the inductive sensor. In some embodiments, the host computer may also be an external device, such as a computer, a PC, an IoT control center, etc., which will not be listed here.

[0100] It is not difficult to see that this embodiment is a system embodiment corresponding to the sensor embodiment, and this embodiment can be implemented in conjunction with the sensor embodiment. The relevant technical details mentioned in the sensor embodiment are still valid in this embodiment, and will not be repeated here to avoid repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the sensor embodiment.

[0101] Furthermore, in order to highlight the innovative aspects of this application, no units that are not closely related to solving the technical problems proposed in this application are introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0102] A third aspect of this application also provides a terminal device, including: an inductive sensor as described in any of the preceding embodiments, or an inductive sensing system as described in any of the preceding embodiments.

[0103] In some embodiments, the terminal device includes a housing, and an inductive sensor or inductive sensing system is disposed within the housing to protect the inductive sensor or inductive sensing system.

[0104] In some embodiments, the terminal device may also include external devices connected to the inductive sensor or inductive sensing system, such as display devices, input devices, etc., which will not be described in detail here.

[0105] It is not difficult to see that this embodiment is a device embodiment corresponding to the foregoing embodiments, and this embodiment can be implemented in conjunction with the foregoing embodiments. The relevant technical details mentioned in the foregoing embodiments are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the foregoing embodiments.

[0106] Furthermore, in order to highlight the innovative aspects of this application, no units that are not closely related to solving the technical problems proposed in this application are introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0107] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. An inductive sensor, characterized in that, include: Oscillator circuit; An excitation coil is connected to the oscillator circuit. N receiving coils are coaxially arranged with the excitation coil, and the receiving coils are staggered sequentially around the axis. ; A signal processing circuit is connected to the N receiving coils; Where N takes values ​​in the range [4, ..., ],in, , , , , , It is the inner radius of the N receiving coils. It is the outer radius of the N receiving coils. , It is the minimum allowable linewidth on the substrate where the N receiving coils are located. It is the minimum allowable line spacing on the substrate where the N receiving coils are located. Let m be the number of dielectric layers on the substrate containing the N receiving coils that can be used to deploy the N receiving coils, and m be the number of parallel channels per row of the N receiving coils. m=1 when the N receiving coils have no return current, or when there is return current but it is not routed through the dielectric layer containing the N receiving coils; m=2 when the N receiving coils have return current and the return current is routed through the dielectric layer containing the N receiving coils. This is the preset protection factor.

2. The inductive sensor according to claim 1, characterized in that, N is related to the order of the harmonics generated by the inductive sensor.

3. The inductive sensor according to claim 1 or 2, characterized in that, The signal processing circuit includes an input interface, a signal processing sub-circuit, and an output interface connected in sequence. The input interface is connected to each of the N receiving coils.

4. The inductive sensor according to claim 3, characterized in that, The signal processing sub-circuit includes a lookup table and a multiply-accumulator; The input interface, the lookup table, the multiply-accumulate unit, and the output interface are connected in sequence, and the input interface and the lookup table are connected through N signal channels; The lookup table stores rotation coefficients that map the N signals generated by the N receiving coils or the digital signals corresponding to the N signals into M orthogonal signals, where M is a positive integer.

5. The inductive sensor according to claim 4, characterized in that, The signal processing sub-circuit includes M multiply-accumulators, and each of the M multiply-accumulators is connected to the output interface.

6. The inductive sensor according to claim 4 or 5, characterized in that, M=2。 7. The inductive sensor according to claim 1 or 2, characterized in that, The excitation coil and / or the N receiving coils are mounted on a PCB board.

8. An inductive sensing system, characterized in that, include: The inductive sensor as described in any one of claims 1 to 7, and the host computer connected to the inductive sensor; The host computer is used to acquire and process the signals and / or data output by the signal processing circuit in the inductive sensor.

9. A terminal device, characterized in that, include: The inductive sensor as described in any one of claims 1 to 7, or the inductive sensing system as described in claim 8.

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