Inductive sensor, sensing system and terminal equipment

Abstract

The invention relates to the technical field of inductive sensors, in particular to an inductive sensor, a sensing system and terminal equipment. An inductive sensor includes: an oscillator circuit; the exciting coil is connected with the oscillator circuit; and the N receiving coils and the excitation coil are coaxially arranged, and the receiving coils in the N receiving coils are sequentially staggered around a shaft by a signal processing circuit and are connected with the N receiving coils. The measurement precision and accuracy of the inductive sensor can be improved at least under the condition that the measurement result is corrected without depending on a filtering algorithm or a compensation algorithm and the like.

Description

Technical Field

[0001] This application relates to the field of inductive sensor technology, and in particular to an inductive sensor, sensing system and terminal device. Background Technology

[0002] Inductive sensors are devices that measure non-electrical quantities by utilizing changes in the self-inductance or mutual inductance of coils. They can be used to measure parameters such as displacement, pressure, vibration, strain, and flow rate. Inductive sensors offer a range of advantages, including simple structure, high sensitivity, high output power, low output impedance, strong anti-interference capability, and high measurement accuracy, making them widely used in electromechanical control systems.

[0003] However, current inductive sensors suffer from measurement bias and low accuracy. Summary of the Invention

[0004] This application provides an inductive sensor, a sensing system, and a terminal device, which at least helps to improve the measurement accuracy and precision of the inductive sensor without relying on filtering algorithms or compensation algorithms to correct the measurement results.

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

[0006] In some embodiments, the range of N is: in, W r =r out -r in , r in r is the inner radius of the N receiving coils. out It is the outer radius of the N receiving coils, p = ω min +s min ω min It is the minimum allowable linewidth on the substrate where the N receiving coils are located, s min n is the minimum allowable line spacing on the substrate containing the N receiving coils. layersThe number of dielectric layers on the substrate where the N receiving coils are located is the number of layers on which the N receiving coils can be deployed. m is the number of parallel channels per row of the N receiving coils. When the N receiving coils have no return current, or have 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. α is a preset protection coefficient.

[0007] In some embodiments, N ≥ N', where N' is the maximum order of the harmonics 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, wherein the input interface is connected to each of the N receiving coils.

[0009] In some embodiments, the signal processing sub-circuit includes a lookup table and a multiply-accumulator; the input interface, the lookup table, the multiply-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 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.

[0010] In some embodiments, the signal processing sub-circuit includes M multiply-accumulators, and the M multiply-accumulators are respectively 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 disposed on a PCB board.

[0013] According to some embodiments of this application, a second aspect of this application also provides an inductive sensing system, including: an inductive sensor as described in any one of the first aspects, 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.

[0014] According to some embodiments of this application, a third aspect of this application also provides a terminal device, including: an inductive sensor as described in any one of the first aspects of this application, or an inductive sensing system as described in the second aspect of this application.

[0015] The technical solution provided in this application embodiment has at least the following advantages:

[0016] In an inductive sensor, a series of staggered positions are set around the axis. The N receiving coils enable the signals generated on the N receiving coils to effectively suppress higher-order harmonics, thereby reducing the interference of these harmonics on the measurement results without relying on filtering algorithms or compensation algorithms to correct the measurement results, thus improving the accuracy and precision of the measurement. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a schematic diagram of the structure of an inductive sensor provided in one embodiment of this application;

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

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

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

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

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

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

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

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

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

[0028] Figure 11 This is a schematic diagram of the structure of an inductive sensor provided in another embodiment of this application. Detailed Implementation

[0029] As can be seen from the background technology, current inductive sensors have measurement biases and low accuracy.

[0030] Analysis revealed that the aforementioned problems stemmed from the fact that the coils in inductive sensors, due to physical characteristics such as the number of turns, shape, and phase asymmetry, may introduce non-ideal errors, generating higher-order harmonics, such as the third and fifth harmonics. When the receiving coil generates its output signal, it is inevitably affected by these harmonic signals, leading to signal distortion during transmission. In the commonly used two-phase 90° equally spaced receiving coil design, this ultimately impacts the measurement accuracy of the inductive sensor. For example, it can cause signal distortion, especially the superposition of harmonic components and the fundamental frequency, affecting measurement accuracy and potentially causing deviations in angle calculations. Furthermore, it can increase angle errors; interference from higher-order harmonic frequency components makes the sensor's angle estimation inaccurate, particularly in dynamic scenarios, making it difficult for the system to maintain high precision.

[0031] Meanwhile, although the effects of harmonics can be corrected from an algorithmic perspective, existing signal processing methods cannot completely eliminate the interference of higher-order harmonics. More complex filtering or compensation algorithms are needed for correction, which increases computational complexity and response time. This leads to both increased costs and implementation difficulty.

[0032] Therefore, in order to solve the accuracy degradation problem caused by high-order harmonic interference without relying on filtering or compensation algorithms to correct the measurement results, this application provides an inductive sensor, sensing system, and terminal device, which achieves this by setting sequentially offset around an axis. The N receiving coils cancel out the higher-order harmonics in the signals on the N receiving coils, thus effectively suppressing the higher-order harmonics. This improves the calculation accuracy of the inductive sensor without relying on filtering or compensation algorithms to correct the measurement results, and achieves higher-precision measurement.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

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

[0035] The first aspect of this application provides an inductive sensor, the structure of which is as follows: Figure 1 As shown, it includes:

[0036] Oscillator circuit 100;

[0037] The excitation coil 200 is connected to the oscillator circuit 100;

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

[0039] The signal processing circuit 400 is connected to N receiving coils 300.

[0040] Therefore, after the AC 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, based on the induction effect, the rotor will react to the electromagnetic field and change the electromagnetic field. This causes the N receiving coils 300 to generate induced signals based on the changed electromagnetic field, which are then output to the signal processing circuit 400. The signal processing circuit 400 processes the induced signals and outputs them. In this process, the reaction effect of the rotor on the electromagnetic field changes with the movement of the rotor, and thus the induced signals also change. Therefore, by analyzing the output of the signal processing circuit 400, the movement process of the rotor can be measured, that is, the physical quantities (such as displacement, angle, etc.) in the rotor movement can be measured. Specifically, since the receiving coils 301 of the N receiving coils 300 are sequentially staggered around the axis... The induced signals generated on the receiving coil 301 interact with each other, canceling out at least some of the higher-order harmonic signals, thus suppressing the higher-order harmonic signals. This reduces the interference of higher-order harmonics on the measurement results without relying on filtering or compensation algorithms to correct the measurement results, thereby improving the accuracy and precision of the measurement.

[0041] To facilitate understanding of the above-mentioned high-order harmonic suppression effect, the following explanation will take the example of the induced signals generated by each receiving coil 301 on N receiving coils 300 being mapped onto the αβ surface as the output signal of an inductive sensor.

[0042] Because the receiving coils 301 of the N receiving coils 300 are sequentially misaligned around the axis Therefore, the induced signal generated on the k-th 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. The signal processing circuit is connected to the N receiving coils.

2. The inductive sensor according to claim 1, characterized in that, The range of values ​​for N is in, W r =r out -r in , r in r is the inner radius of the N receiving coils. out It is the outer radius of the N receiving coils, p = ω min +s min ω min It is the minimum allowable linewidth on the substrate where the N receiving coils are located, s min n is the minimum allowable line spacing on the substrate containing the N receiving coils. layers The number of dielectric layers on the substrate where the N receiving coils are located is the number of layers on which the N receiving coils can be deployed. m is the number of parallel channels per row of the N receiving coils. When the N receiving coils have no return current, or have 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. α is a preset protection coefficient.

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

4. The inductive sensor according to any one of claims 1 to 3, 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.

5. The inductive sensor according to claim 4, 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.

6. The inductive sensor according to claim 5, 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.

7. The inductive sensor according to claim 4 or 5, characterized in that, M＝2。 8. The inductive sensor according to any one of claims 1 to 3, characterized in that, The excitation coil and / or the N receiving coils are mounted on a PCB board.

9. An inductive sensing system, characterized in that, include: The inductive sensor as described in any one of claims 1 to 8, 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.

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

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