Electromagnetic coupling sensing device, signal measurement method and electronic device

Abstract

The application discloses an electromagnetic coupling sensing device, a signal measuring method and an electronic device. A frequency generating module is configured to generate a set frequency signal; a first resonance module is configured to generate a primary resonance signal based on the set frequency signal; a second resonance module is configured to be connected with the first resonance module through a coupling capacitor to generate a secondary resonance signal based on the primary resonance signal; wherein the second resonance module comprises a coil arranged in a Z direction, a ferrite arranged in the coil, and the height of the coil is higher than the ferrite; the coil can bear a weight to be measured to generate a deformation to change the frequency of the secondary resonance signal; and a echo acquisition and processing module is configured to be connected with the second resonance module to acquire the secondary resonance signal and output a voltage signal changed according to the secondary resonance signal.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, and in particular to an electromagnetic coupling sensing device, a signal measurement method, and an electronic device. Background Technology

[0002] With the global popularization of artificial intelligence, mechanical equipment has been widely used on assembly lines to replace workers in heavy manual labor, greatly improving social productivity. On the other hand, mechanical equipment is also gradually becoming more common in households, such as intelligent robotic vacuum cleaners, coffee machines, and food delivery robots. Whether in industrial or daily life scenarios, intelligent equipment requires the replenishment of raw materials. Therefore, it is necessary to detect the remaining amount of raw materials so that they can be replenished in time when supplies are low or nearing shortage, avoiding resource waste caused by machines being unable to operate due to material shortages.

[0003] Currently, solid materials are typically measured by piece count, length count, or weight count. Liquids and gases are typically measured by volume calculation (or flow rate calculation) or weight count. Volume sensors or weight sensors are generally used for measurement. However, both volume and weight sensors are linear devices, so their sensitivity is limited by the mechanism of the device itself. Summary of the Invention

[0004] The purpose of this application is to improve the accuracy of existing gas / liquid quality detection. To achieve this technical objective, the following technical solution is adopted.

[0005] According to a first aspect of the present invention, an electromagnetic coupling sensing device is provided, comprising: a frequency generating module configured to generate a set frequency signal;

[0006] A first resonant module is configured to generate a primary resonant signal based on the set frequency signal;

[0007] A second resonant module is configured to be coupled to the first resonant module via a coupling capacitor to generate a secondary resonant signal based on the primary resonant signal; wherein the second resonant module includes a coil arranged in the Z direction, a ferrite is disposed inside the coil and the height of the coil is higher than the ferrite; the coil is capable of bearing the weight to be measured so that deformation causes a change in the eigenfrequency of the electromagnetic coupling sensing device.

[0008] An echo acquisition and processing module is configured to be connected to the second resonant module to acquire the secondary resonant signal and output a voltage signal that varies according to the intrinsic frequency of the electromagnetic coupling sensing device.

[0009] Furthermore, the echo acquisition and processing module includes: a sampling unit, an operational amplifier unit, and a voltage comparison unit;

[0010] The current of the secondary resonant signal passes sequentially through the sampling unit, the operational amplifier unit, and the voltage comparison unit to output the voltage signal.

[0011] Furthermore, the electromagnetic coupling sensing device also includes:

[0012] A microprocessor;

[0013] The microprocessor is connected to the output of the voltage comparison unit in the echo acquisition and processing module to receive the voltage signal and output quality data.

[0014] Furthermore, the frequency generation module includes a crystal oscillator, and the electromagnetic coupling sensing device further includes a microprocessor, a driving component, and a switching transistor component;

[0015] The switching transistor assembly includes a first switching transistor Q1 and a second switching transistor Q2, with the sources of the first switching transistor Q1 and the second switching transistor Q2 connected to a common terminal.

[0016] The drain of the first switch Q1 is connected to the first resonant module, and the drain of the first switch Q1 is connected to a DC power supply.

[0017] The drain of the second switch Q2 is connected to the second resonant module;

[0018] The microprocessor is connected to the driving component, which is connected to the drain of the first switching transistor Q1 and the drain of the second switching transistor Q2. The driving component is also connected to the gate control terminal of the first switching transistor Q1 and the gate control terminal of the second switching transistor Q2, so as to convert the DC power supply into a square wave with the same frequency as the crystal oscillator and input it to the first resonant module and the second resonant module.

[0019] Furthermore, the coil is a copper coil, and the diameter of the coil ranges from 0.2mm to 1mm.

[0020] Furthermore, the number of turns of the coil ranges from 5 to 100 turns.

[0021] Furthermore, the thickness of the ferrite ranges from 33% to 66% of the height of the coil under relaxed conditions.

[0022] Furthermore, the ferrite is cylindrical with a diameter ranging from 4.5 mm to 48 mm.

[0023] Furthermore, the first resonant module includes:

[0024] First frequency input terminal, first frequency output terminal, first coupling terminal, and second coupling terminal;

[0025] An inductor is connected between the first frequency input terminal and the first coupling terminal;

[0026] A first capacitor is connected between the first frequency output terminal and the second coupling terminal;

[0027] The first coupling end and the second coupling end are coupled to the second resonant module.

[0028] Furthermore, the second resonant module includes:

[0029] A third coupling terminal and a fourth coupling terminal; the third coupling terminal is connected to the first coupling terminal, the fourth coupling terminal is connected to the second coupling terminal, and the coil and the second capacitor are connected in series between the third coupling terminal and the fourth coupling terminal; the first coupling terminal and the second coupling terminal are connected through a coupling capacitor.

[0030] Furthermore, the electromagnetic coupling sensing device includes:

[0031] Strain gauge;

[0032] The strain gauge is connected to the upper end of the coil.

[0033] Furthermore, the electromagnetic coupling sensing device also includes:

[0034] Frame;

[0035] A column is provided on the frame, and the ferrite is sleeved on the column.

[0036] Furthermore, the electromagnetic coupling sensing device also includes:

[0037] Power module;

[0038] The power supply module is connected to the frequency generation module and / or the echo acquisition and processing module, and is used to step down the input power supply voltage and supply power to the frequency generation module and / or the echo acquisition and processing module.

[0039] According to a second aspect of the present invention, a signal measurement method is provided, applied to an electromagnetic coupling sensing device as provided in any possible embodiment of the first aspect, the method comprising:

[0040] Connect to power;

[0041] The object to be tested is placed on the coil to deform the coil.

[0042] The voltage signal output by the echo acquisition and processing module is measured, and the voltage signal changes according to the intrinsic frequency of the electromagnetic coupling sensing device.

[0043] According to a third aspect of the present invention, an electronic device includes: an electromagnetic coupling sensing device as provided in any possible embodiment of the first aspect.

[0044] The beneficial technical effects of this application are as follows:

[0045] The electromagnetic coupling sensing device provided in this application inputs an intrinsic frequency, which, after passing through the first resonant module and the second resonant module, ensures that the two resonant circuits have the same intrinsic resonant frequency in the initial state of the system. The loss rate of the electromagnetic coupling sensing device is determined by the equivalent resistance R of the coil in the second resonant module at the rear end. When the loss is appropriately adjusted, the system can be made to be in a critical coupling state. This application utilizes the sensitivity near the critical coupling to improve the detection sensitivity.

[0046] The electromagnetic coupling sensing device provided in this application is ideal for improving the measurement accuracy of electronic equipment. Attached Figure Description

[0047] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this application in any way. Furthermore, the shapes and scales of the components in the drawings are merely illustrative to aid in understanding this application and do not specifically limit the shapes and scales of the components. Those skilled in the art, guided by the teachings of this application, can select various possible shapes and scales to implement this application according to specific circumstances. In the drawings:

[0048] Figure 1 This is an equivalent schematic diagram of an electromagnetic coupling sensing device according to an exemplary embodiment of this application;

[0049] Figure 2 This is a schematic diagram of the electromagnetic coupling hardware topology of an electromagnetic coupling sensing device according to an exemplary embodiment of this application;

[0050] Figure 3 This is an equivalent schematic diagram of an electromagnetic coupling sensing device according to another exemplary embodiment of this application;

[0051] Figure 4 This is a schematic diagram of the coil structure of an electromagnetic coupling sensing device according to an exemplary embodiment of this application;

[0052] Figure 5 This is a schematic diagram of the echo acquisition and processing module of an electromagnetic coupling sensing device according to an exemplary embodiment of this application;

[0053] Figure 6 This is a schematic diagram of an electronic device according to an exemplary embodiment of this application;

[0054] Figure label:

[0055] 1-Frequency generation module, 2-First resonant module, 3-Second resonant module, 4-Echo acquisition and processing module, 5-Coupled capacitor, 6-Microprocessor, 7-Driver assembly, 8-Switch transistor assembly, 9-DC power supply, 10-Power supply module, 11-Electromagnetic coupling sensing device, 12-Electronic device, 21-First frequency input terminal, 22-First frequency output terminal, 23-First coupling terminal, 24-Second coupling terminal, 25-Inductor, 26-First capacitor, 31-Third coupling terminal, 32-Fourth coupling terminal, 33-Coil, 34-Second capacitor, 35-Resistor, 36-Ferrite, 37-Column, 38-Strain gauge, 39-Frame. Detailed Implementation

[0056] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0057] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of this disclosure are only used to distinguish different steps, devices or modules, and do not represent any specific technical meaning, nor do they indicate the logical order between them.

[0058] It should also be understood that in the embodiments disclosed herein, "a plurality of" may refer to two or more, and "at least one" may refer to one, two or more.

[0059] Throughout the specification and claims, when an element is described as being “connected” to another element, that element may be “directly connected” to the other element or “electrically connected” to the other element via a third element.

[0060] Furthermore, unless explicitly stated otherwise, the word "includes" will be understood to mean the included elements but not the exclusion of any other elements.

[0061] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0062] Traditional volumetric methods are primarily used when the measured value is only in volume units. There are generally two calculation methods: the first calculates the material used per unit by fixing the structural components and then calculates the remaining material; this method only allows for calculation of the usage per unit based on the fixed structural components. The second method uses a flow meter to calculate the gas / liquid flow rate through the pipeline in real time. However, regardless of the method used, the final result is still the volume parameter of the material used in the equipment. Since the unit of measurement for gas / liquid storage and containerization is usually mass, the process from volume to mass calculation must utilize density calculation formulas.

[0063] m = ρ * V,

[0064] Where ρ is the gas / liquid density, m is the mass, and V is the measurement volume.

[0065] As is well known, the density of gases / liquids changes significantly with temperature, making the above measurement methods less suitable for scenarios requiring high precision. Similarly, mass measurement typically involves weight testing, followed by calculation using the formula:

[0066] m = G / g,

[0067] Where G is the measured gravity, m is the mass, and g is the gravitational acceleration 9.8 N / kg.

[0068] The working principle of a weight measurement sensor is that gravity causes deformation of the strain gauge, the core component of the sensor. The magnitude of the deformation is converted into a resistance value, and the change in resistance value is then measured to achieve high-precision weight detection. Similarly, since the strain gauge is a completely solid metal structure, it is also subject to thermal expansion, which can lead to accuracy deviations.

[0069] In recent years, electromagnetic near-field coupling has become a major research focus. When two electromagnetic resonant units with the same frequency approach each other, a coupling frequency split occurs at the eigenfrequency of the resonant unit. Researchers have found that this split disappears when the loss parameters and coupling parameters of the system are matched. Based on this theory, researchers introduced the concept of parity-time (PT) symmetry in quantum mechanics and termed the lossy physical system as a non-Hermitian system. Surprisingly, researchers discovered that when the system is at the point where the frequency split merges, the eigenmode sensitivity to perturbations is related to the half-power of the sensitivity of a single resonant unit. Therefore, researchers believe that this system is very suitable as a fundamental principle for sensors, and some sensors are already gradually utilizing this physical mechanism to achieve high-precision detection.

[0070] Please refer to the equivalent schematic diagram of the electromagnetic coupling sensing device provided in the specific embodiments of this application. Figure 1 ,like Figure 1As shown, the electromagnetic coupling sensing device includes:

[0071] Frequency generation module 1 is configured to generate a set frequency signal;

[0072] First resonant module 2, the first resonant module 2 is used to generate a primary resonant signal based on a set frequency signal;

[0073] The second resonant module 3 is configured to be coupled to the first resonant module 2 via a coupling capacitor 5 to generate a secondary resonant signal based on the primary resonant signal. The second resonant module 3 includes a coil 33 arranged in the Z direction, a ferrite 36 disposed inside the coil 33, and the height of the coil 33 is higher than that of the ferrite 36. The coil 33 can bear the weight to be measured so that it deforms and changes the eigenfrequency of the electromagnetic coupling sensing device 11.

[0074] The echo acquisition and processing module 4 is configured to be connected to the second resonant module 3. The echo acquisition and processing module 4 acquires the secondary resonant signal and outputs a voltage signal that varies according to the intrinsic frequency of the electromagnetic coupling sensing device 11.

[0075] Frequency generation module 1 generates a signal of a fixed frequency. First resonant module 2 generates an oscillation signal, which excites coil 33 in second resonant module 3 with a high-frequency current, thus generating a high-frequency current with a certain frequency corresponding to the weight to be measured. The output voltage of the excitation current of coil 33 is generated by echo acquisition and processing module 4.

[0076] In some specific embodiments, the frequency generation module 1 may employ, but is not limited to, a crystal oscillator with a fixed frequency.

[0077] In other embodiments, the frequency generation module 1 can employ a high-precision RC circuit or an internal output of a sufficiently accurate MCU. The advantage of a crystal oscillator is its high frequency accuracy and good temperature stability. In this application, the accuracy of the frequency generation module 1 is directly determined by the accuracy of the electromagnetic coupling sensing device 11.

[0078] After being powered on, the frequency generation module 1 (such as a crystal oscillator) transmits a square wave signal of a fixed frequency to the back-end electromagnetic coupling hardware topology (which includes a first resonant module 2 and a second resonant module 3). The transmission frequency is determined by the frequency of the back-end electromagnetic coupling hardware topology. The square wave signal is reflected back to the echo acquisition and processing module 4 after passing through the electromagnetic coupling hardware topology. After being processed by the echo acquisition and processing module 4, the output voltage signal is used to calibrate the weight of the detected target.

[0079] Optionally, the upper end of coil 33 can move along the Z direction, i.e., deform as it bears weight, while the lower end of coil 33 is fixed.

[0080] The electromagnetic coupling sensing device 11 provided in this application uses a coil 33 arranged in the Z direction to achieve deformation after bearing weight. The inductance of the coil 33 serves as the strain due to weight bearing deformation, thereby affecting the local oscillator frequency of the electromagnetic coupling sensing device. The electromagnetic coupling sensing device 11 provided in this application not only has high measurement accuracy and sensitivity, but also has a simple structure and is easy to implement.

[0081] In a specific embodiment, the echo acquisition and processing module 4 may include a rectifier circuit and a filter circuit, and then amplify it to a suitable ratio through an operational amplifier.

[0082] In some embodiments, such as Figure 5 As shown, the echo acquisition and processing module 4 includes a sampling unit, an operational amplifier unit, and a voltage comparison unit. The current i1 of the secondary resonant signal passes through the sampling unit, the operational amplifier unit, and the voltage comparison unit in sequence, and outputs a voltage signal.

[0083] like Figure 5 As shown, the sampling unit includes a third resistor R3 and a fourth resistor R4. The node on the line connecting the third resistor R3 and the fourth resistor R4 is connected to one input terminal of the second operational amplifier Op2 via diode D1. The other input terminal of the second operational amplifier Op2 is connected to its output terminal via the second resistor R2. The output terminal of the second operational amplifier Op2 is connected to one input terminal of the first operational amplifier Op1 via the first resistor R1. The other input terminal of the first operational amplifier Op1 receives the reference voltage u. ref The first operational amplifier Op1 outputs a voltage signal.

[0084] The secondary resonant signal current i1 is directly coupled through coil 33 and first undergoes voltage division by two precision resistors, R3 and R4. Then, it is rectified by diode D1 and filtered by capacitor C4 before being input to the second operational amplifier Op2. Op2 is responsible for amplifying the voltage, with the amplification factor controlled by resistors R1 and R2. The signal then enters the first operational amplifier Op1 for zero-crossing comparison to remove noise signals. ref The reference voltage is used for comparison; finally, the output voltage signal is filtered by capacitor C3; optionally, the output voltage can be connected to microprocessor 6.

[0085] In some embodiments, the electromagnetic coupling sensing device further includes a microprocessor 6, which is connected to the output of the voltage comparison unit to receive voltage signals and output quality data. The microprocessor 6 can be implemented using existing technology, which will not be described in detail.

[0086] In some embodiments, such as Figure 5 As shown, the frequency generation module 1 includes a crystal oscillator, and the electromagnetic coupling sensing device 11 also includes a microprocessor 6, a drive component 7, and a switching transistor component 8.

[0087] The switching transistor assembly 8 includes a first switching transistor Q1 and a second switching transistor Q2, with the sources of the first switching transistor Q1 and the second switching transistor Q2 connected to a common terminal;

[0088] The drain of the first switching transistor Q1 is connected to the first resonant module, and the drain of the first switching transistor Q1 is connected to the DC power supply.

[0089] The drain of the second switch Q2 is connected to the second resonant module.

[0090] The microprocessor 6 is connected to the drive component 7, which is connected to the drain of the first switch Q1 and the gate control terminals of the second switch Q2, respectively, so as to convert the DC power supply 9 into a square wave with the same frequency as the crystal oscillator and input it to the electromagnetic coupling hardware topology (including the first resonant module 120 and the second resonant module 130).

[0091] The driving component 7 mainly converts the transmitter signal of the microprocessor 6 into a driving signal that can drive the MOSFETs; the first switch Q1 and the second switch Q2 are two MOSFETs. Figure 5 The inverter topology is a Double-Class-E high-frequency inverter topology, characterized by a zero-voltage switch (ZVS), low losses, and distortion-free high-frequency inversion. Currently, the output power of MCUs can only reach the mW level, but the circuit provided in this embodiment, including a microprocessor 6, a driver component 7, and a switching transistor component 8, can output power in the W level. Due to the increased drive power, this embodiment is less affected by environmental interference, thereby improving detection accuracy.

[0092] Figure 5 In the diagram, inductor Lc1 is the transmitter freewheeling inductor, mainly responsible for power supply and filtering.

[0093] The microprocessor 6 can output detection signals or update analysis methods via GPIO input / output ports.

[0094] In specific embodiments, the first resonant module 2 may employ an existing oscillation circuit, and in some embodiments, for example, an LC oscillator may be used.

[0095] In a specific embodiment, the coil 33 is wound in a spiral shape, with a ferrite 36 disposed in the middle, which can reduce the leakage magnetic field and improve the sensitivity of the sensing device. The height of the coil 33 is higher than the height of the ferrite 36.

[0096] like Figure 1In the illustrated embodiment, the first resonant module 2 of the electromagnetic coupling sensing device 11 employs an LC oscillation circuit. Since the system operates at a fixed frequency, the principle of the electromagnetic coupling sensing device provided in this application is that the voltage at the original frequency changes due to the eigenfrequency of the LC circuit in the electromagnetic coupling hardware topology shifting from the original frequency. The conversion ratio between voltage and weight is approximately determined by the amplitude of the LC resonant circuit in the second resonant module 3, i.e., the LC resonant circuit in which the coil 33 operates.

[0097] Figure 1 The electromagnetic coupling sensing device is shown to consist of two sets of LC resonant circuits connected in series (first resonant module 2 and second resonant module 3), with coupling between the two sets of LC circuits achieved through a coupling capacitor 150C0. The electromagnetic coupling hardware topology is as follows. Figure 1 The right side and Figure 2 As shown.

[0098] Specifically, the first resonant module 2 may include a first frequency input terminal 21, a first frequency output terminal 22, a first coupling terminal 23, and a second coupling terminal 24.

[0099] An inductor 25 is connected between the first frequency input terminal 21 and the first coupling terminal 23;

[0100] A first capacitor 26 is connected between the first frequency output terminal 22 and the second coupling terminal 24.

[0101] The first coupling terminal 23 and the second coupling terminal 24 are coupled to the second resonant module 3.

[0102] The second resonant module 3 includes a third coupling terminal 31 and a fourth coupling terminal 32; the third coupling terminal 31 is connected to the first coupling terminal 23, and the fourth coupling terminal 32 is connected to the second coupling terminal; a coil 33 and a second capacitor 34 are connected in series between the third coupling terminal 31 and the fourth coupling terminal 32; the first coupling terminal 23 and the second coupling terminal 24 are connected through a coupling capacitor 5. A ferrite 36 is placed in the coil 33, which can be equivalent to connecting an equivalent resistor 35 in series in the coil 33 circuit.

[0103] The intrinsic resonant frequencies ω of the two resonant circuits can be obtained using formula (I), expressed as:

[0104]

[0105] System settings To ensure that the two resonant circuits have the same intrinsic resonant frequency in the initial state of the system, L 11 L 22 These are the inductance values ​​of the inductors in the two resonant circuits, C. 11 C 22 C represents the capacitance values ​​of the capacitors in the two resonant circuits, respectively. 00This is the coupling capacitance between the two resonant circuits.

[0106] To simplify the model, physical quantities are used instead of electrical quantities to describe the system. In this case, the equations of motion for the two resonant circuits in the system can be described by formula (II), as follows:

[0107]

[0108] in, Describe the current oscillation state of two resonant circuits, ω 1,2 =ω0 is the eigenfrequency of the two resonant circuits, ω is the frequency of the crystal oscillator input, and γ is the system loss rate determined by the equivalent resistance R at the back end, with the relationship γ = R / 2L, S in Let be the voltage amplitude at the input terminal, i be the sign of a complex number, and κ represent the near-field coupling strength or near-field coupling coefficient between the first and second resonant circuits, expressed as: Where k0 is the capacitive coupling coefficient.

[0109] By rewriting the system's equations of motion, the system's Hamiltonian matrix can be further obtained, expressed as formula (III).

[0110]

[0111] By solving for the determinant of matrix H, the eigenmodes of the system can be further obtained, expressed as formula (IV).

[0112]

[0113] Consider ω 1,2 When ω = 0, the above formula (IV) can be written as:

[0114]

[0115] By appropriately adjusting the equivalent resistance R to regulate losses, the system can be brought to a critical coupling state, i.e. This application utilizes the sensitivity near the critical coupling to improve detection sensitivity. Here, the inductance (inductance value L) in the second resonant circuit is used. 11 As the weight-bearing deformation strain, when introduced into the system, it corresponds to adding a perturbation Δω to the intrinsic frequency ω2. Therefore, formula (IV) can be further rewritten as:

[0116]

[0117] Further solving yields If the relationship is a power of 1 / 2, then for subtle changes, this precision will be further amplified.

[0118] In summary, the electromagnetic coupling sensing device 11 provided in this application is very suitable as a solution to improve the detection accuracy and sensitivity requirements of the system.

[0119] The embodiment is built based on a theoretical model, wherein the electromagnetic coupling hardware topology in the electromagnetic coupling sensing device module is as follows: Figure 1 As shown, inductor 25 (L1), coupling capacitor 5 (C0), first capacitor 26 (C1), and second capacitor 34 (C2) are lumped elements. Coil 33 (L2) is a flexible coil assembly with a certain height of ferrite 36 in the middle to increase the change range of inductance L2 of coil 33 after deformation and increase the contrast of the sensing device. In a specific embodiment, the height of coil 33 must be higher than ferrite 36 (or iron core) by a certain distance.

[0120] In some embodiments, the coil 33 is made of copper wire with a diameter of 0.2mm to 1mm, optionally using copper wire with a diameter of 0.2mm, 0.5mm, or 1mm; the number of turns of the spiral winding depends on the specific dimensions, ranging from 5 to 100 turns, optionally 5, 8, 20, 50, or 100 turns, and the diameter of the spiral winding is controlled between 5mm and 50mm, such as 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, and 50mm. This preferred embodiment enables the electromagnetic coupling sensing device 11 to have relatively superior sensitivity and stability.

[0121] Since the ferrite 36 needs to be housed within the helical structure of the coil 33, the diameter of the ferrite 36 must be smaller than the diameter of the helix. The diameter of the ferrite 36 ranges from 4.5mm to 48mm, such as 4.5mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, and 48mm. This preferred design achieves a relative balance between space requirements and magnetic field strength requirements.

[0122] In a specific embodiment, the thickness of the ferrite 36 is controlled to be the height of the coil 33 in a 33% to 66% relaxed state, such as the height of the coil 33 in a 33%, 40%, 50%, or 66% relaxed state.

[0123] When unloaded, the height h of coil 33 is 7.4 mm, and the inductance L2 of coil 33 is 0.065 uH. After deformation under load, the height h of coil 33 can vary from 6 mm to 7.4 mm, and the inductance L2 of coil 33 can vary from 0.065 uH to 0.09 uH. The final feedback to the deformation mass variation range is 0–146 kg, and the normal operating range is set to 0–50 kg.

[0124] The parameters of other components in the system are set as follows: L1 = L2 = 0.065uH under no-load conditions, C1 = C2 = 6.8nF, C0 = 2.2nF. The final design operating frequency is 13.56MHz, with input provided by a fixed crystal oscillator. When the system weight changes, the height h of the strain flexible coil 33 changes, causing a change in the inductance L2 of the coil 33. This results in a frequency drift of ω2, leading to an increase in the reflection of the fixed input ω0 = 13.56MHz. After echo acquisition and processing module 4, the output voltage value increases. Ultimately, this signal can be fed back to the MCU to obtain the weight test result.

[0125] In some embodiments, the electromagnetic coupling sensing device may include a power supply module 10, such as Figure 3 As shown, when the system power is input, the power module 10 will reduce the input 5 / 9 / 12V DC voltage to 3.3 / 5V to supply power to the frequency generation module 1 (such as a crystal oscillator) and the echo acquisition and processing module 4.

[0126] By setting a power module 10 in the electromagnetic coupling sensing device, the range of power supply voltage is expanded, and power supply regulation and filtering are realized, making the entire device more adaptable and reliable.

[0127] The electromagnetic coupling sensing device 11 provided in this application, unlike traditional stress sensors which ultimately obtain a voltage value, works by stress changing resistance, with the change in resistance feeding back to the final voltage (e.g., by designing a voltage divider circuit). This application uses a coil assembly at a fixed frequency to form a resonant voltage in an LC circuit, obtaining the voltage value through voltage inductance. If the coil 33 in the sensing device experiences greater pressure, the LC frequency shifts more severely, resulting in a lower resonant voltage. In this case, an AC signal is obtained, which, after rectification and filtering, becomes a DC signal, which is then amplified by an operational amplifier to obtain a voltage signal output.

[0128] It is understood that in other embodiments, based on the above embodiments, modules such as communication modules, display modules, and voice modules can also be integrated into the electromagnetic coupling sensing device 11 to realize functions such as data communication with other devices, data display, and voice input playback. Communication modules include, but are not limited to, 2G / 3G / 4G / 5G modules, Wi-Fi modules, Zigbee modules, LoRa, NB-IoT, Bluetooth, etc.

[0129] In other embodiments, such as Figure 4 As shown, a strain gauge 38 can be installed at the upper end of the coil 33. The strain gauge 38 can be made of a non-magnetic responsive material (engineering plastic, carbon fiber, or ceramic, etc.), and has a structure that produces a certain deformation after being subjected to force. When selecting the strain gauge 38, attention should be paid to ensuring that its Young's modulus is within a reasonable range. Optionally, the strain gauge 38 and the coil 33 can be connected by a slot or glued together.

[0130] In some embodiments, to fix the lower end of the coil 33, the electromagnetic coupling sensing device may optionally include a frame 39, on which a column 37 is disposed. Ferrite 36 is sleeved on the column 37 and fixed to the frame 39. The strain gauge 38 can move up and down along the column 37 as the coil 33 deforms. The column 37 can be a common cylindrical structure with a relatively small Young's modulus.

[0131] Ferrite 36 can be adhesively bonded to the bottom of frame 39. Column 37 can be metal or a material with sufficient structural strength, integrally molded with or connected to frame 39 with high strength (welding or high-strength adhesive). Optionally, frame 39 also includes sidewalls. Optionally, frame 39 is a metal shell, primarily serving as shielding and providing structural strength.

[0132] This application also provides a signal measurement method, applied to the electromagnetic coupling sensing device provided in the above embodiments, including:

[0133] Connect to power;

[0134] The weight to be measured is placed on coil 33 to cause coil 33 to deform.

[0135] The voltage signal output by the measurement echo acquisition and processing module 4 changes according to the intrinsic frequency of the electromagnetic coupling sensing device.

[0136] Furthermore, embodiments of the present invention also provide an electrical device 12, such as... Figure 6 As shown, the electrical equipment 12 may include the electromagnetic coupling sensing device 11 as described above.

[0137] The aforementioned electrical equipment may be, for example, any one of the following: electronic scale, weight sensor, intelligent robotic vacuum cleaner, coffee machine, food delivery robot, etc., or other portable or intelligent devices not listed above.

[0138] According to embodiments of the present invention, the electromagnetic coupling sensing device in the electrical equipment can improve the accuracy of weight measurement.

[0139] For hardware implementation, the microprocessor 6 can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions of this application, or combinations thereof.

[0140] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by microprocessor 6. The memory can be implemented in microprocessor 6 or external to microprocessor 6.

[0141] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0142] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0143] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed application subject matter.

Claims

1. An electromagnetic coupling sensing device, characterized in that, include: A frequency generation module, configured to generate a set frequency signal; A first resonant module is configured to generate a primary resonant signal based on the set frequency signal; The first resonant module includes: a first frequency input terminal, a first frequency output terminal, a first coupling terminal, and a second coupling terminal; an inductor is connected between the first frequency input terminal and the first coupling terminal; a first capacitor is connected between the first frequency output terminal and the second coupling terminal; the first coupling terminal and the second coupling terminal are connected through a coupling capacitor. A second resonant module is configured to be coupled to the first resonant module via a coupling capacitor to generate a secondary resonant signal based on the primary resonant signal. The second resonant module includes a coil positioned in the Z-direction, a third coupling terminal, and a fourth coupling terminal. Ferrite is disposed within the coil, and the height of the coil exceeds the height of the ferrite. The coil is capable of bearing the weight to be measured, causing deformation that alters the intrinsic frequency of the electromagnetic coupling sensing device. The third coupling terminal is connected to the first coupling terminal, and the fourth coupling terminal is connected to the second coupling terminal. The coil and the second capacitor are connected in series between the third and fourth coupling terminals. An echo acquisition and processing module is configured to be connected to the second resonant module to acquire the secondary resonant signal and output a voltage signal that varies according to the intrinsic frequency of the electromagnetic coupling sensing device.

2. The electromagnetic coupling sensing device according to claim 1, characterized in that, The echo acquisition and processing module includes: a sampling unit, an operational amplifier unit, and a voltage comparison unit; The current of the secondary resonant signal passes sequentially through the sampling unit, the operational amplifier unit, and the voltage comparison unit to output the voltage signal.

3. The electromagnetic coupling sensing device according to claim 2, characterized in that, The electromagnetic coupling sensing device further includes a microprocessor, which is connected to the output terminal of the voltage comparison unit to receive the voltage signal and output quality data.

4. The electromagnetic coupling sensing device according to claim 1, characterized in that, The frequency generation module includes a crystal oscillator, and the electromagnetic coupling sensing device further includes a microprocessor, a driving component, and a switching transistor component. The switching transistor assembly includes a first switching transistor Q1 and a second switching transistor Q2, with the sources of the first switching transistor Q1 and the second switching transistor Q2 connected to a common terminal. The drain of the first switch Q1 is connected to the first resonant module, and the drain of the first switch Q1 is connected to a DC power supply. The drain of the second switch Q2 is connected to the second resonant module; The microprocessor is connected to the driving component, which is connected to the drain of the first switch Q1 and the drain of the second switch Q2 respectively. The driving component is also connected to the gate control terminal of the first switch Q1 and the gate control terminal of the second switch Q2, so as to convert the DC power supply into a square wave with the same frequency as the crystal oscillator and input it to the first resonant module and the second resonant module.

5. The electromagnetic coupling sensing device according to claim 1, characterized in that, The coil is a copper coil with a diameter ranging from 0.2 mm to 1 mm.

6. The electromagnetic coupling sensing device according to claim 1, characterized in that, The number of turns of the coil ranges from 5 to 100.

7. The electromagnetic coupling sensing device according to claim 1, characterized in that, The thickness of the ferrite ranges from 33% to 66% of the coil height under relaxed conditions.

8. The electromagnetic coupling sensing device according to claim 1, characterized in that, The ferrite is cylindrical with a diameter ranging from 4.5 mm to 48 mm.

9. The electromagnetic coupling sensing device according to claim 1, characterized in that, The electromagnetic coupling sensing device includes: Strain gauge; The strain gauge is connected to the upper end of the coil.

10. The electromagnetic coupling sensing device according to claim 9, characterized in that, The electromagnetic coupling sensing device further includes: Frame; A column is provided on the frame, and the ferrite is sleeved on the column.

11. The electromagnetic coupling sensing device according to claim 1, characterized in that, The electromagnetic coupling sensing device further includes: Power module; The power supply module is connected to the frequency generation module and / or the echo acquisition and processing module, and is used to step down the input power supply voltage and supply power to the frequency generation module and / or the echo acquisition and processing module.

12. A signal measurement method, characterized in that, Applied to the electromagnetic coupling sensing device as described in any one of claims 1 to 11, characterized in that the method comprises: Connect to power; The object to be tested is placed on the coil to deform the coil; The voltage signal output by the echo acquisition and processing module is measured, and the voltage signal changes according to the intrinsic frequency of the electromagnetic coupling sensing device.

13. An electronic device, characterized in that, include: The electromagnetic coupling sensing device as described in any one of claims 1 to 11.

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